WorldWideScience

Sample records for cassava starch hydrolysate

  1. Fermentation and recovery of L-glutamic acid from cassava starch hydrolysate by ion-exchange resin column

    Directory of Open Access Journals (Sweden)

    Nampoothiri K. Madhavan

    1999-01-01

    Full Text Available Investigations were carried out with the aim of producing L-glutamic acid from Brevibacterium sp. by utilizing a locally available starchy substrate, cassava (Manihot esculenta Crantz. Initial studies were carried out in shake flasks, which showed that even though the yield was high with 85-90 DE (Dextrose Equivalent value, the maximum conversion yield (~34% was obtained by using only partially digested starch hydrolysate, i.e. 45-50 DE. Fermentations were carried out in batch mode in a 5 L fermenter, using suitably diluted cassava starch hydrolysate, using a 85-90 DE value hydrolysate. Media supplemented with nutrients resulted in an accumulation of 21 g/L glutamic acid with a fairly high (66.3% conversation yield of glucose to glutamic acid (based on glucose consumed and on 81.74% theoretical conversion rate. The bioreactor conditions most conducive for maximum production were pH 7.5, temperature 30°C and an agitation of 180 rpm. When fermentation was conducted in fed-batch mode by keeping the residual reducing sugar concentration at 5% w/v, 25.0 g/L of glutamate was obtained after 40 h fermentation (16% more the batch mode. Chromatographic separation by ion-exchange resin was used for the recovery and purification of glutamic acid. It was further crystallized and separated by making use of its low solubility at the isoelectric point (pH 3.2.

  2. Resistant starch in cassava products

    OpenAIRE

    Bruna Letícia Buzati Pereira; Magali Leonel

    2014-01-01

    Found in different foods, starch is the most important source of carbohydrates in the diet. Some factors present in starchy foods influence the rate at which the starch is hydrolyzed and absorbed in vivo. Due the importance of cassava products in Brazilian diet, the objective of this study was to analyze total starch, resistant starch, and digestible starch contents in commercial cassava products. Thirty three commercial cassava products from different brands, classifications, and origin were...

  3. Cassava starch in the Brazilian food industry

    OpenAIRE

    Ivo Mottin Demiate; Valesca Kotovicz

    2011-01-01

    Cassava starch is a valued raw material for producing many kinds of modified starches for food applications. Its physicochemical properties, as well as its availability, have made it an interesting and challenging ingredient for the food industry. In the present work, food grade modified cassava starches were purchased from producers and analyzed for selected physicochemical characteristics. Samples of sour cassava starch were included, as well as one sample of native cassava starch. Results ...

  4. Cassava starch in the Brazilian food industry

    Directory of Open Access Journals (Sweden)

    Ivo Mottin Demiate

    2011-06-01

    Full Text Available Cassava starch is a valued raw material for producing many kinds of modified starches for food applications. Its physicochemical properties, as well as its availability, have made it an interesting and challenging ingredient for the food industry. In the present work, food grade modified cassava starches were purchased from producers and analyzed for selected physicochemical characteristics. Samples of sour cassava starch were included, as well as one sample of native cassava starch. Results showed that almost all modified starches were resistant to syneresis, produced pastes more stable to stirred cooking, and some of them were difficult to cook. The sour cassava starches presented high acidity and resulted in clear and unstable pastes during stirred cooking, susceptible to syneresis.

  5. Genetic modification of cassava enhances starch production

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Recently, a field test of transgenic cassava (Manihot esculenta Crantz) for enhanced starch production by the Shanghai Institute of Plant Physiology & Ecology (SIPPE), the CAS Shanghai Institutes for Biological Sciences, proved successful. Through application of transgenic technologies in cassava, the starch quality of this tropical root crop was largely improved. The new cassava cultivars are believed to have a tremendous potential for industrial application in the future.

  6. Properties of baked foams from citric acid modified cassava starch and native cassava starch blends.

    Science.gov (United States)

    Pornsuksomboon, Kanlaya; Holló, Berta Barta; Szécsényi, Katalin Mészáros; Kaewtatip, Kaewta

    2016-01-20

    Starch foams from native cassava starch (NS) and citric acid modified cassava starch (CNS) were prepared using baking processes with blend ratios of 80/20, 60/40, 50/50, 40/60 and 20/80. The density, thickness, morphology, thermal stability and water absorption of the NS, CNS and blended starch foams were determined. The ratio of the two starch components had a significant influence on the density and thickness of the blended starch foams. All blended starch foams showed good water resistance. Moreover, the morphology of the blended starch foam with the NS/CNS ratio of 50/50 showed a more ordered distribution of cell sizes with thicker cell walls than for the NS and CNS foams. The thermal stability of the blended starch foams was somewhat lower than the stability of the NS foam but not to the extent that it affected any potential practical applications.

  7. Properties of baked foams from citric acid modified cassava starch and native cassava starch blends.

    Science.gov (United States)

    Pornsuksomboon, Kanlaya; Holló, Berta Barta; Szécsényi, Katalin Mészáros; Kaewtatip, Kaewta

    2016-01-20

    Starch foams from native cassava starch (NS) and citric acid modified cassava starch (CNS) were prepared using baking processes with blend ratios of 80/20, 60/40, 50/50, 40/60 and 20/80. The density, thickness, morphology, thermal stability and water absorption of the NS, CNS and blended starch foams were determined. The ratio of the two starch components had a significant influence on the density and thickness of the blended starch foams. All blended starch foams showed good water resistance. Moreover, the morphology of the blended starch foam with the NS/CNS ratio of 50/50 showed a more ordered distribution of cell sizes with thicker cell walls than for the NS and CNS foams. The thermal stability of the blended starch foams was somewhat lower than the stability of the NS foam but not to the extent that it affected any potential practical applications. PMID:26572335

  8. Properties of thermoplastic starch from cassave bagasse and cassava starch and their blends with poly (lactic acid).

    Science.gov (United States)

    Cassava bagasse is an inexpensive and broadly available waste byproduct from cassava starch production. It contains roughly 50% cassava starch along with mostly fiber and could be a valuable feedstock for various bioproducts. Cassava bagasse and cassava starch were used in this study to make fiber-r...

  9. A Comparative Study of Some Properties of Cassava and Tree Cassava Starch Films

    Science.gov (United States)

    Belibi, P. C.; Daou, T. J.; Ndjaka, J. M. B.; Nsom, B.; Michelin, L.; Durand, B.

    Cassava and tree cassava starch films plasticized with glycerol were produced by casting method. Different glycerol contents (30, 35, 40 and 45 wt. % on starch dry basis) were used and the resulting films were fully characterized. Their water barrier and mechanical properties were compared. While increasing glycerol concentration, moisture content, water solubility, water vapour permeability, tensile strength, percent elongation at break and Young's modulus decreased for both cassava and tree cassava films. Tree cassava films presented better values of water vapour permeability, water solubility and percent elongation at break compared to those of cassava films, regardless of the glycerol content.

  10. An Integrated Investment Appraisal of Cassava Starch Production in Rwanda: The Case of Kinazi Cassava Plant

    OpenAIRE

    Alice Nsenkyire; Glenn P. Jenkins; Mikhail Miklyaev; Octave Semwaga

    2015-01-01

    In April 2012, Kinazi Cassava Plant was established as a government initiative to produce high quality cassava flour, and other value added cassava products. After the successful establishment of the cassava flour plant in Ruhango district, KCP now plans to diversify into cassava starch production to feed the emerging manufacturing industries such as the pharmaceuticals, food processing, breweries, textiles etc. both domestically and for exportation. The study assesses the financial and econo...

  11. Anaerobic digestion of cassava starch factory effluent.

    Science.gov (United States)

    Manilal, V B; Narayanan, C S; Balagopalan, C

    1990-06-01

    Biomethanation of cassava starch factory effluent in a batch digester produced 130 l biogas/kg dry matter with an average melthane content of 59%. About 63% COD was removed during 60 days. In semicontinuous digesters, gas production was 3251/kg dry matter with a retention time of 33,3 days giving a COD reduction of 50%. Size of starter inoculum was important for good biogasification of the effluent.

  12. Radiation processing of cassava starch hydrogel

    International Nuclear Information System (INIS)

    This paper consists of two topics on cassava starch (CS). The first paper deals with radiation-induced graft polymerization of 1-vinyl-2-pyrrolidinone (VP) onto CS. The results from PVP -grafted-starch were subsequently compared with those of PVP hydrogels and PVP-blended-starch hydrogels. It was found that the PVP-grafted-starch hydrogels, with gel fraction higher than 80%, could be prepared at the dose of 20 kGy, while PVP and PVP-blended-starch hydrogels require at least 30 kGy to obtain gels with more than 80% gel fraction. And at the same dose used for irradiation, the gel strength of the PVP-grafted-starch hydrogels is significantly higher than that of the PVP and PVP-blended-starch hydrogels. Radiation crosslinking of carboxymethyl CS is the second topic. CS was chemically modified by sodium monochloroacetate (SMCA) to yield carboxymethyl starch (CMS). The aqueous solution of CMS was irradiated and underwent radiation-induced crosslinking, resulting in a crosslinked CMS (XLCMS) hydrogel. The optimum condition for obtaining hydrogels with desirable properties is irradiation at low dose, 2 kGy. At higher doses, the gel fraction tends to diminish, due to the domination of degradation over crosslinking. (author)

  13. Study on the Rheological Property of Cassava Starch Adhesives

    Directory of Open Access Journals (Sweden)

    Junjun Liu

    2014-03-01

    Full Text Available The main goal of this study was to use cassava starch in the production of environmentally sound adhesives. ‘Three-formaldehyde glue’ pollutes the environment and harms to human health strongly, which widely used for wood-based panels preparation. Environment-friendly cassava starch adhesives were prepared using method of oxidation-gelatinization, insteading of the three formaldehyde glue. The effects of the quality ratio of starch and water, temperature and shear rate on the apparent viscosity of the adhesive were studied. The rheological eigenvalue of apparent viscosity was studied through nonlinear regression. The results showed that the apparent viscosity of cassava starch adhesives decreased with the increasing of temperature; the apparent viscosity decreased slowly with the increasing of rotor speed; the phenomenon of shear thinning appeared within cassava starch adhesives which was pseudo-plastic fluids. Cassava starch adhesives with characteristics of non-toxic, no smell and pollution could be applied in interior and upscale packaging.

  14. High temperature simultaneous saccharification and fermentation of starch from inedible wild cassava (Manihot glaziovii) to bioethanol using Caloramator boliviensis.

    Science.gov (United States)

    Moshi, Anselm P; Hosea, Ken M M; Elisante, Emrode; Mamo, G; Mattiasson, Bo

    2015-03-01

    The thermoanaerobe, Caloramator boliviensis was used to ferment starch hydrolysate from inedible wild cassava to ethanol at 60°C. A raw starch degrading α-amylase was used to hydrolyse the cassava starch. During fermentation, the organism released CO2 and H2 gases, and Gas Endeavour System was successfully used for monitoring and recording formation of these gaseous products. The bioethanol produced in stoichiometric amounts to CO2 was registered online in Gas Endeavour software and correlated strongly (R(2)=0.99) with values measured by HPLC. The organism was sensitive to cyanide that exists in cassava flour. However, after acclimatisation, it was able to grow and ferment cassava starch hydrolysate containing up to 0.2ppm cyanide. The reactor hydrogen partial pressure had influence on the bioethanol production. In fed-batch fermentation by maintaining the hydrogen partial pressure around 590Pa, the organism was able to ferment up to 76g/L glucose and produced 33g/L ethanol.

  15. Characteristics of cassava starch fermentation wastewater based on structural degradation of starch granules

    OpenAIRE

    Juliane Mascarenhas Pereira; Ana Carolina Moura de Sena Aquino; Daiana Cardoso de Oliveira; Gabriela Rocha; Alícia de Francisco; Pedro Luiz Manique Barreto; Edna Regina Amante

    2016-01-01

    ABSTRACT: Sour cassava starch is a naturally modified starch produced by fermentation and sun drying, achieving the property of expansion upon baking. Sour cassava starch' bakery products can be prepared without the addition of yeast and it is gluten free. The fermentation process associated with this product has been well studied, but the wastewater, with high acidity and richness in other organic compounds derived from starch degradation, requires further investigation. In this study, the s...

  16. MOISTURE ISOTHERMS OF CASSAVA BAGASSE COMPOSITES IMPREGNATED WITH CASSAVA STARCH ACETATE SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Kátia N. MATSUI

    2009-07-01

    Full Text Available

    The industrial processing of cassava to obtain starch generates a great variety of residues, with bagasse being the main solid residue produced. The improper disposal of this material represents an environmental problem and could be avoided by using this residue as a raw material to obtain biodegradable products. The bagasse produced during the process to obtain starch from cassava was used to prepare composites for disposable trays. Samples of the composites were impregnated with cassava starch acetate at atmospheric pressure and under vacuum condition. Moisture isotherms were determined and adjusted by GAB model. It was observed that the impregnation promoted an important decrease in sample higroscopicity, mainly at high relative humidities. These results suggest that starch acetate impregnation can be an alternative to water proofing biological materials like the composites obtained in this work. KEYWORDS: Cassava; bagasse; starch acetate; impregnation; isotherms.

  17. Biogas Production From Cassava Starch Effluent Using Microalgae As Biostabilisator

    OpenAIRE

    B. Budiyono; Tutuk Djoko Kusworo

    2011-01-01

    The rapid growing of Indonesian population is emerging several critical national issues i.e. energy, food, environmental, water, transportation, as well as law and human right. As an agricultural country, Indonesia has abundant of biomass wastes such as agricultural wastes include the cassava starch wastes. The problem is that the effluent from cassava starch factories is released directly into the river before properly treatment. It has been a great source of pollution and has caused environ...

  18. Electrical and absorption properties of fresh cassava tubers and cassava starch

    Science.gov (United States)

    Harnsoongnoen, S.; Siritaratiwat, A.

    2015-09-01

    The objective of this study was to analyze the electrical and absorption properties of fresh cassava tubers and cassava starch at various frequencies using electric impedance spectroscopy and near-infrared spectroscopy, as well as determine the classification of the electrical parameters of both materials using the principle component analysis (PCA) method. All samples were measured at room temperature. The electrical and absorption parameters consisted of dielectric constant, dissipation factor, parallel capacitance, resistance, reactance, impedance and absorbance. It was found that the electrical and absorption properties of fresh cassava tubers and cassava starch were a function of frequency, and there were significant differences between the materials. The dielectric constant, parallel capacitance, resistance and impedance of fresh cassava tubers and cassava starch had similar dramatic decreases with increasing frequency. However, the reactance of both materials increased with an increasing frequency. The electrical parameters of both materials could be classified into two groups. Moreover, the dissipation factor and phase of impedance were the parameters that could be used in the separation of both materials. According to the absorbance patterns of the fresh cassava tubers and cassava starch, there were significant differences.

  19. Electrical and absorption properties of fresh cassava tubers and cassava starch

    International Nuclear Information System (INIS)

    The objective of this study was to analyze the electrical and absorption properties of fresh cassava tubers and cassava starch at various frequencies using electric impedance spectroscopy and near-infrared spectroscopy, as well as determine the classification of the electrical parameters of both materials using the principle component analysis (PCA) method. All samples were measured at room temperature. The electrical and absorption parameters consisted of dielectric constant, dissipation factor, parallel capacitance, resistance, reactance, impedance and absorbance. It was found that the electrical and absorption properties of fresh cassava tubers and cassava starch were a function of frequency, and there were significant differences between the materials. The dielectric constant, parallel capacitance, resistance and impedance of fresh cassava tubers and cassava starch had similar dramatic decreases with increasing frequency. However, the reactance of both materials increased with an increasing frequency. The electrical parameters of both materials could be classified into two groups. Moreover, the dissipation factor and phase of impedance were the parameters that could be used in the separation of both materials. According to the absorbance patterns of the fresh cassava tubers and cassava starch, there were significant differences

  20. MOISTURE ISOTHERMS OF CASSAVA BAGASSE COMPOSITES IMPREGNATED WITH CASSAVA STARCH ACETATE SOLUTIONS

    OpenAIRE

    KáTIA N. MATSUI; FáBIO D. S. LAROTONDA; Alfredo T. N. Pires; JOãO B. LAURINDO

    2009-01-01

    The industrial processing of cassava to obtain starch generates a great variety of residues, with bagasse being the main solid residue produced. The improper disposal of this material represents an environmental problem and could be avoided by using this residue as a raw material to obtain biodegradable products. The bagasse produced during the process to obtain starch from cassava was used to prepare composites for disposable trays. Samples of the composites were imp...

  1. SACCHARIFICATION OF NATIVE CASSAVA STARCH AT HIGH DRY SOLIDS IN AN ENZYMATIC MEMBRANE REACTOR

    Directory of Open Access Journals (Sweden)

    I Nyoman Widiasa

    2012-02-01

    Full Text Available This study is aimed to develop a novel process scheme for hydrolysis of native cassava starch at high dry solids using an enzymatic membrane reactor (EMR. Firstly, liquefied cassava starch having solids content up to 50% by weight was prepared by three stage liquefactions in a conventional equipment using a commercially available heat stable a-amylase (Termamyl 120L. The liquefied cassava starch was further saccharified in an EMR using glucoamylase (AMG E. By using the developed process scheme, a highly clear hydrolysate with dextrose equivalent (DE approximately 97 could be produced, provided the increase of solution viscosity during the liquefaction was precisely controlled. The excessive space time could result in reduction in conversion degree of starch. Moreover, a residence time distribution study confirmed that the EMR could be modelled as a simple continuous stirred tank reactor (CSTR. Using Lineweaver-Burk analysis, the apparent Michaelis-Menten constant (Km and glucose production rate constant (k2 were 552 (g/l and 4.04 (min-1, respectively. Application of simple CSTR model with those kinetic parameters was quietly appropriate to predict the reactor’s performance at low space time.

  2. Origins of the poor filtration characteristics of wheat starch hydrolysates

    NARCIS (Netherlands)

    Matser, A.M.; Steeneken, P.A.M.

    1998-01-01

    The effects of wheat starch components on the filtration characteristics of wheat starch hydrolysates were investigated with a model-based approach. The filtration rate was not affected by the removal of the pentosans or by altering the conformation of the protein. On the other hand, the filtration

  3. Properties of Cassava Starch Modified by Amylomaltase from Corynebacterium glutamicum.

    Science.gov (United States)

    Suriyakul Na Ayudhaya, Pitcha; Pongsawasdi, Piamsook; Laohasongkram, Kalaya; Chaiwanichsiri, Saiwarun

    2016-06-01

    Amylomaltase (α-1,4-glucanotransferase, AM; EC 2.4.1.25) from Corynebacterium glutamicum expressed in Escherichia coli was used to prepare the enzyme-modified cassava starch for food application. About 5% to 15% (w/v) of cassava starch slurries were incubated with 1, 3, or 5 units of amylomaltase/g starch. Apparent amylose, amylopectin chain length distribution, thermal properties, freeze-thaw stability, thermo-reversibility, and gel strength of the obtained modified starches were measured. The apparent amylose content and retrogradation enthalpy were lower, whereas the retrogradation temperatures, freeze-thaw stability, and thermo-reversibility were higher than those of the native cassava starch. However, when amylomaltase content was increased to 20 units of amylomaltase/g starch and for 24 h, the modified starch showed an improvement in the thermo-reversibility property. When used in panna cotta, the gel strength of the sample using the 20 units/24 h modified cassava starch was similar to that of using gelatin. PMID:27105125

  4. Characters related to higher starch accumulation in cassava storage roots.

    Science.gov (United States)

    Li, You-Zhi; Zhao, Jian-Yu; Wu, San-Min; Fan, Xian-Wei; Luo, Xing-Lu; Chen, Bao-Shan

    2016-01-01

    Cassava (Manihot esculenta) is valued mainly for high content starch in its roots. Our understanding of mechanisms promoting high starch accumulation in the roots is, however, still very limited. Two field-grown cassava cultivars, Huanan 124(H124) with low root starch and Fuxuan 01(F01) with high root starch, were characterised comparatively at four main growth stages. Changes in key sugars in the leaves, stems and roots seemed not to be strongly associated with the final amount of starch accumulated in the roots. However, when compared with H124, F01 exhibited a more compact arrangement of xylem vascular bundles in the leaf axils, much less callose around the phloem sieve plates in the stems, higher starch synthesis-related enzymatic activity but lower amylase activity in the roots, more significantly up-regulated expression of related genes, and a much higher stem flow rate (SFR). In conclusion, higher starch accumulation in the roots results from the concurrent effects of powerful stem transport capacity highlighted by higher SFR, high starch synthesis but low starch degradation in the roots, and high expression of sugar transporter genes in the stems. A model of high starch accumulation in cassava roots was therefore proposed and discussed.

  5. Characters related to higher starch accumulation in cassava storage roots.

    Science.gov (United States)

    Li, You-Zhi; Zhao, Jian-Yu; Wu, San-Min; Fan, Xian-Wei; Luo, Xing-Lu; Chen, Bao-Shan

    2016-01-01

    Cassava (Manihot esculenta) is valued mainly for high content starch in its roots. Our understanding of mechanisms promoting high starch accumulation in the roots is, however, still very limited. Two field-grown cassava cultivars, Huanan 124(H124) with low root starch and Fuxuan 01(F01) with high root starch, were characterised comparatively at four main growth stages. Changes in key sugars in the leaves, stems and roots seemed not to be strongly associated with the final amount of starch accumulated in the roots. However, when compared with H124, F01 exhibited a more compact arrangement of xylem vascular bundles in the leaf axils, much less callose around the phloem sieve plates in the stems, higher starch synthesis-related enzymatic activity but lower amylase activity in the roots, more significantly up-regulated expression of related genes, and a much higher stem flow rate (SFR). In conclusion, higher starch accumulation in the roots results from the concurrent effects of powerful stem transport capacity highlighted by higher SFR, high starch synthesis but low starch degradation in the roots, and high expression of sugar transporter genes in the stems. A model of high starch accumulation in cassava roots was therefore proposed and discussed. PMID:26892156

  6. Effect of carboxymethyl cellulose concentration on physical properties of biodegradable cassava starch-based films

    OpenAIRE

    Sriburi Pensiri; Wongruong Sasitorn; Mauer Lisa J; Tongdeesoontorn Wirongrong; Rachtanapun Pornchai

    2011-01-01

    Abstract Background Cassava starch, the economically important agricultural commodity in Thailand, can readily be cast into films. However, the cassava starch film is brittle and weak, leading to inadequate mechanical properties. The properties of starch film can be improved by adding plasticizers and blending with the other biopolymers. Results Cassava starch (5%w/v) based films plasticized with glycerol (30 g/100 g starch) were characterized with respect to the effect of carboxymethyl cellu...

  7. Biogas Production From Cassava Starch Effluent Using Microalgae As Biostabilisator

    Directory of Open Access Journals (Sweden)

    B. Budiyono

    2011-07-01

    Full Text Available The rapid growing of Indonesian population is emerging several critical national issues i.e. energy, food, environmental, water, transportation, as well as law and human right. As an agricultural country, Indonesia has abundant of biomass wastes such as agricultural wastes include the cassava starch wastes. The problem is that the effluent from cassava starch factories is released directly into the river before properly treatment. It has been a great source of pollution and has caused environmental problems to the nearby rural population. The possible alternative to solve the problem is by converting waste to energy biogas in the biodigester. The main problem of the biogas production of cassava starch effluent is acid forming-bacteria quickly produced acid resulting significantly in declining pH below the neutral pH and diminishing growth of methane bacteria. Hence, the only one of the method to cover this problem is by adding microalgae as biostabilisator of pH. Microalgae can also be used as purifier agent to absorb CO2.The general objective of this research project was to develop an integrated process of biogas production and purification from cassava starch effluent by using biostabilisator agent microalgae. This study has been focused on the used of urea, ruminant, yeast, microalgae, the treatment of gelled and ungelled feed for biogas production, pH control during biogas production using buffer Na2CO3, and feeding management in the semi-continuous process of biogas production. The result can be concluded as follows: i The biogas production increased after cassava starch effluent and yeast was added, ii Biogas production with microalgae and cassava starch effluent, yeast, ruminant bacteria, and urea were 726.43 ml/g total solid, iii Biogas production without  microalgae was 189 ml/g total solid.

  8. Performance Evaluation of Local Cassava Starches with Imported Starch for Drilling Fluid

    Directory of Open Access Journals (Sweden)

    Harry, T.F.

    2016-10-01

    Full Text Available Local cassava starches and an imported starch were characterized and evaluated for their performance as drilling fluid additives. Two local cassava cultivars, TMS 98/0581 and TMS 96/1632, starches and an imported starch were characterized by using X-ray diffraction techniques. Bentonite mud beneficiated with the starches were subjected to API viscosity and filtration tests. The local and imported starches were classified as B type crystal structure. The starches average particle sizes were 51.63nm, 23.57nm and 57.94nm for TMS 98/0581, TMS 96/1632 and imported starches respectively. The crystalline indices were between 22 and 35, while average specific surface areas were 151.65, 361.28 and 142.04 m2 /g for TMS 98/0581, TMS 96/1632 and imported starches respectively. The morphology indices, ranges were from 0.5 to 0.7485. The structural properties of TMS 98/0581 starch were found to be significantly close to that of the imported starch and were observed to be closer in performance as drilling fluid additive than TMS 96/1632. Local cassava starches with structural properties as TMS 98/0581, could serve as good substitute for drilling operation. The viscosity and fluid loss control results of the local samples compared favourably with the imported one.

  9. Morphological and mechanical characterization of thermoplastic starch and its blends with polylactic acid using cassava starch and bagasse

    Science.gov (United States)

    This study aims the use of an agro waste coming from the industrialization of cassava starch, known as cassava bagasse (BG). This material contains residual starch and cellulose fibers which can be used to obtain thermoplastic starch (TPS) and /or blends reinforced with fibers. In this context, it w...

  10. Study of cassava starch enzymatic modification for maltodextrins obtention

    OpenAIRE

    Miguel Angel Díaz; María Isabel Filella; Velásquez, Mario E.

    2012-01-01

    It was pretended to investigate the effect of the most relevant variables in cassava starch enzymatic hydrolysis process, on laboratory scale, to determine appropriate industrial conditions for the obtention of different kinds of maltodextrins. An a-Amylase enzyme, from genetically modified strain of Bacillus lichenijormis, was used to hydrolize the starch. Once the variables were chosen, an experimental fractioned factorial design was established with two levels. The Dextrose Equivalent (DE)...

  11. Cassava starch effluent treatment with concomitant SCP production.

    Science.gov (United States)

    Manilal, V B; Narayanan, C S; Balagopalan, C

    1991-03-01

    Yeasts and yeast-like organisms were chosen for the aerobic treatment of cassava starch factory effluent. A mixed culture of Candida utills and Endomycopsis fibuliger efficiently and rapidly utilized both starch and free sugars. After 28 h fermentation the protein content of the biomass was 22% (w/w), which remained unchanged during the remainder of the fermentation (60 h). This treatment removed 94% of the COD and 91% of the BOD.

  12. Physicochemical properties of cassava starch oxidized by sodium hypochlorite.

    Science.gov (United States)

    Garrido, Lúcia Helena; Schnitzler, Egon; Zortéa, Manoela Estefânea Boff; de Souza Rocha, Thaís; Demiate, Ivo Mottin

    2014-10-01

    In this work, cassava starch was modified by treatment with sodium hypochlorite (NaClO) at different concentrations (0.8, 2.0 and 5.0 % of active chlorine) and selected physicochemical properties of the oxidized starches were investigated. The native and modified samples were evaluated considering moisture, carboxyl content, apparent viscosity, susceptibility to syneresis, mid-infrared spectroscopy and crystallinity index. The treatment with NaClO resulted in alterations in carboxyl content of the oxidized starches that increased with increasing concentration of the oxidant. Oxidized starches also showed higher susceptibility to syneresis, as assessed by the release of liquid during freezing and thawing. Apparent viscosity analysis showed decrease in peak viscosity of the oxidized starches. X-ray diffractograms showed that the oxidation influenced the extent of cassava starch relative crystallinity found to lie between 34.4 % (native) and 39.9 % (2.0 % active chlorine). The infrared spectra are sensitive to structural changes on starch macromolecules and presented characteristic peaks as C-O-C of the six carbon glucose ring absorbs at 1,150-1,085 cm(-1) and due to axial deformation these bands changed with the crystal structure of the starch samples.

  13. Cassava flour and starch : progress in research and development

    OpenAIRE

    Giraud, Eric; Brauman, Alain; Kéléke, S.; Gosselin, Laurent; Raimbault, Maurice

    1996-01-01

    An amylolytic lactic acid bacterium, identified as #Lactobacillus plantarum$, was isolated from cassava roots (#Manihot esculenta$ var. Ngansa) during retting. Cultured on starch, the strain displayed a growth rate of 0.43 per hour, a biomass yield of 0.19 g/g, and a lactate yield of 0.81 g/g. The growth kinetics were similar on starch and glucose. Enough enzyme was synthesized, and starch hydrolysis was not a limiting factor for growth. The synthesized amylolytic enzyme was purified by fract...

  14. Ethanol production of banana shell and cassava starch

    International Nuclear Information System (INIS)

    In this work the acid hydrolysis of the starch was evaluated in cassava and the cellulose shell banana and its later fermentation to ethanol, the means of fermentation were adjusted for the microorganisms saccharomyces cerevisiae nrrl y-2034 and zymomonas mobilis cp4. The banana shell has been characterized, which possesses a content of starch, cellulose and hemicelluloses that represent more than 80% of the shell deserve the study of this as source of carbon. The acid hydrolysis of the banana shell yield 20g/l reducing sugar was obtained as maximum concentration. For the cassava with 170 g/l of starch to ph 0.8 in 5 hours complete conversion is achieved to you reducing sugars and any inhibitory effect is not noticed on the part of the cultivations carried out with banana shell and cassava by the cyanide presence in the cassava and for the formation of toxic compounds in the acid hydrolysis the cellulose in banana shell. For the fermentation carried out with saccharomyces cerevisiae a concentration of ethanol of 7.92± 0.31% it is achieved and a considerable production of ethanol is not appreciated (smaller than 0.1 g/l) for none of the means fermented with zymomonas mobilis

  15. Thermoanalytical and starch content evaluation of cassava bagasse as agro-industrial residue

    OpenAIRE

    Luiz Gustavo Lacerda; Rafael Ramires Almeida; Ivo Mottin Demiate; Marco Aurélio Silva Carvalho Filho; Eliane Carvalho Vasconcelos; Adenise Lorenci Woiciechowski; Gilbert Bannach; Egon Schnitzler; Carlos Ricardo Soccol

    2009-01-01

    Starch nutritional fractions as well as thermal properties and other analysis are essential for food and industrial application. Cassava bagasse is an important agro-industrial residue and its starch content was evaluated using two alternative methods. Thermal characterization and microscopy analyses helped to understand how hydrolysis digests starchy fraction of cassava bagasse. The melting point of cassava starch occurred at 169.2ºC. Regarding TG analyses, after moisture content, there were...

  16. Amylase binding to starch granules under hydrolysing and non-hydrolysing conditions.

    Science.gov (United States)

    Dhital, Sushil; Warren, Frederick J; Zhang, Bin; Gidley, Michael J

    2014-11-26

    Although considerable information is available about amylolysis rate, extent and pattern of granular starches, the underlying mechanisms of enzyme action and interactions are not fully understood, partly due to the lack of direct visualisation of enzyme binding and subsequent hydrolysis of starch granules. In the present study, α-amylase (AA) from porcine pancreas was labelled with either fluorescein isothiocyanate (FITC) or tetramethylrhodamine isothiocyanate (TRITC) fluorescent dye with maintenance of significant enzyme activity. The binding of FITC/TRITC-AA conjugate to the surface and interior of granules was studied under both non-hydrolysing (0 °C) and hydrolysing (37 °C) conditions with confocal microscopy. It was observed that enzyme binding to maize starch granules under both conditions was more homogenous compared with potato starch. Enzyme molecules appear to preferentially bind to the granules or part of granules that are more susceptible to enzymic degradation. The specificity is such that fresh enzyme added after a certain time of incubation binds at the same location as previously bound enzyme. By visualising the enzyme location during binding and hydrolysis, detailed information is provided regarding the heterogeneity of granular starch digestion.

  17. Utilization of residue from cassava starch processing for production of fermentable sugar by enzymatic hydrolysis

    Directory of Open Access Journals (Sweden)

    Luciana Reis Fontinelle SOUTO

    2016-01-01

    Full Text Available Abstract The aim of this study was to characterize and perform enzymatic hydrolysis of cassava peeling residue (peel and inner peel, mainly composed of peels and small pieces. Residue was sanitized, dried at 55 °C for 24 hours and ground. The obtained flour showed pH of 4.85; 72.53 g 100 g–1 moisture; 5.18 mL 1M NaOH 100 g–1 acidity; 60.68 g 100 g–1 starch; 1.08 g 100 g–1 reducing sugar; 1.63 g 100g–1 ash; 0.86 g 100 g–1 lipid and 3.97 g 100 g–1 protein. Enzymatic hydrolysis was carried out by means of rotational central composite design, analyzing the effects of concentrations of α-amylase enzyme (10 to 50 U g starch–1, and the amyloglucosidase enzyme (80 to 400 U g starch–1 on variable responses: percent conversion of starch into reducing sugars (RSC and soluble solid content (SS. Highest values of RSC (110% and SS (12 °Brix were observed when using the maximum concentration of amyloglucosidase and throughout the concentration range of α-amylase. Enzymatic hydrolysis of cassava peel is feasible and allows the use of hydrolysate in fermentation processes for the production of various products, such as alcoholic drinks, vinegar, among others.

  18. Effect of the improved fermentation on physicochemical properties and sensorial acceptability of sour cassava starch

    OpenAIRE

    Maria Janete Angeloni Marcon; Gisele Cristina Netto Vieira; Karina Nunes de Simas; Karina Santos; Manoela Alano Vieira; Renata Dias de Mello Castanho Amboni; Edna Regina Amante

    2007-01-01

    The aim of this work was to study the effect of improved fermentation on sour cassava starch, aiming to reduce its fermentation time and to enhance its expansion capacity as well as its viscoamylographic properties and its sensorial acceptability. Results showed that the improved process of cassava starch production did not harm starch expansion, physicochemical properties or sensorial acceptability; it also produced starches with different viscoamylographic properties, which compared favoura...

  19. 双酶协同水解木薯淀粉水解液对小球藻生物量和油脂积累的影响%Effect of Cassava Starch Hydrolysate by Two Enzymes on Cell Biomass and Lipid Accumulation of Chlorella protothecoides

    Institute of Scientific and Technical Information of China (English)

    李玉芹; 袁正求; 冯岳; 黎萍; 周蒙; 姚威; 张剑

    2011-01-01

    Objective To observe the effect of cassava starch hydrolysate(CSH) used as a carbon source instead of glucose on cell biomass and lipid accumulation of Chlorella protothecoides. Methods Cassava starch was hydrolyzed with two enzymes, and analyzed for physical characteristics before and after hydrolysis by scanning electron microscopy (SEM) and X-ray diffraction. C. protothecoides were cultured by heterotrophic mode using purified glucose and CSH as carbon sources respectively and urea as a nitrogen source, and determined for biomass by loss on drying, from which total lipid was extracted and analyzed for fatty acid content by gas chromatography-mass spectrometry (GC-MS). Results The optimal temperature, pH value, time, enzyme dosage and substrate concentration for hydrolysis of cassava starch with two enzyme were 70℃, 4. 0, 3 h, 0. 5% and 20 g/L respectively. Under the optimal condition, the content of glucose transformed from CSH was 64. 1 1%. SEM and XRD showed hydrolysis only on the surface of starch particles, without destruction of crystal structure of cassava starch. The biomass and total lipid content of C. protothecoides cultured in the medium containing 40 g/L glucose were 9. 12 and 4. 39 g/L respectively. However, when the CSH at a glucose concentration of 30 g/L was used as a carbon source, the biomass and total lipid content were 9. 50 and 4. 51 g/L, which increased by 4. 17% and 2. 73% as compared with those using glucose as a carbon source respectively. Conclusion CSH is an ideal route to increase the lipid output of microalgae in heterotrophic culture and decrease the production cost of biodiesel.%目的 以木薯淀粉水解液替代葡萄糖异养培养小球藻,观察其对小球藻生物量和油脂积累的影响.方法 采用双酶协同酶解法水解木薯淀粉,扫描电镜和X-射线衍射表征分析水解前后产物的物理特性;分别以精制葡萄糖和木薯淀粉水解液作为碳源,尿素作为氮源,采用异养模

  20. Effects of citric acid esterification on digestibility, structural and physicochemical properties of cassava starch.

    Science.gov (United States)

    Mei, Ji-Qiang; Zhou, Da-Nian; Jin, Zheng-Yu; Xu, Xue-Ming; Chen, Han-Qing

    2015-11-15

    In this study, citric acid was used to react with cassava starch in order to compare the digestibility, structural and physicochemical properties of citrate starch samples. The results indicated that citric acid esterification treatment significantly increased the content of resistant starch (RS) in starch samples. The swelling power and solubility of citrate starch samples were lower than those of native starch. Compared with native starch, a new peak at 1724 cm(-1) was appeared in all citrate starch samples, and crystalline peaks of all starch citrates became much smaller or even disappeared. Differential scanning calorimetry results indicated that the endothermic peak of citrate starches gradually shrank or even disappeared. Moreover, the citrate starch gels exhibited better freeze-thaw stability. These results suggested that citric acid esterification induced structural changes in cassava starch significantly affected its digestibility and it could be a potential method for the preparation of RS with thermal stability.

  1. Molecular evolution and functional divergence of soluble starch synthase genes in cassava (manihot esculenta crantz).

    Science.gov (United States)

    Yang, Zefeng; Wang, Yifan; Xu, Shuhui; Xu, Chenwu; Yan, Changjie

    2013-01-01

    Soluble starch synthases (SSs) are major enzymes involved in starch biosynthesis in plants. Cassava starch has many remarkable characteristics, which should be influenced by the evolution of SS genes in this starchy root crop. In this work, we performed a comprehensive phylogenetic and evolutionary analysis of the soluble starch synthases in cassava. Genome-wide identification showed that there are 9 genes encoding soluble starch synthases in cassava. All of the soluble starch synthases encoded by these genes contain both Glyco_transf_5 and Glycos_transf_1 domains, and a correlation analysis showed evidence of coevolution between these 2 domains in cassava SS genes. The SS genes in land plants can be divided into 6 subfamilies that were formed before the origin of seed plants, and species-specific expansion has contributed to the evolution of this family in cassava. A functional divergence analysis for this family provided statistical evidence for shifted evolutionary rates between the subfamilies of land plant soluble starch synthases. Although the main selective pressure acting on land plant SS genes was purifying selection, our results also revealed that point mutation with positive selection contributed to the evolution of 2 SS genes in cassava. The remarkable cassava starch characteristics might be the result of both the duplication and adaptive selection of SS genes.

  2. Chemical composition, functional and pasting properties of cassava starch and soy protein concentrate blends.

    Science.gov (United States)

    Chinma, Chiemela Enyinnaya; Ariahu, Charles Chukwuma; Abu, Joseph Oneh

    2013-12-01

    The chemical, functional and pasting properties of cassava starch and soy protein concentrate blends intended for biofilm processing were studied. Cassava starch and soy protein concentrates were prepared and mixed at different proportions (100: 0%; 90 : 10%; 80 : 20%; 70 : 30%; 60;40% and 50: 50%). Addition of varying levels of soy protein concentrates to cassava starch led to increases in moisture (from 7.10 to 9.17%), protein ( from 0.32 to 79.03%), ash (from 0.45 to 2.67%) and fat (from 0.17 to 0.98%) contents while crude fiber, carbohydrate and amylose contents decreased from ( 1.19 to 0.38%, 90.77 to 57.01% and 29.45 to 23.04%) respectively . Water absorption capacity and swelling power of cassava starch were improved as a result of soy protein concentrate addition while syneresis and solubility value of composite blends were lower than 100% cassava starch. In general, cassava-soy protein concentrate blends formed firmer gels than cassava starch alone. There were significant (p ≤ 0.05) increases in peak viscosity (from 160.12 to 268.32RVU), final viscosity (from 140.41 to 211.08RVU) and pasting temperature (from 71.00 to 72.32 °C ) of cassava starch due to addition of soy protein concentrate. These results suggest that the addition of soy protein concentrate to cassava starch affected the studied functional properties of cassava starch as evidenced by changes such as reduced syneresis, and solubility that are desirable when considering this biopolymer as an edible biofilm.

  3. Biogas Production Using Anaerobic Biodigester from Cassava Starch Effluent

    Directory of Open Access Journals (Sweden)

    S. Sunarso

    2010-12-01

    Full Text Available IKMs’ factory activity in Margoyoso produces liquid and solid wastes. The possible alternative was to use the liquid effluent as biogas raw material. This study focuses on the used of urea, ruminant, yeast, microalgae, the treatment of gelled and ungelled feed for biogas production, pH control during biogas production using buffer Na2CO3, and feeding management in the semi-continuous process of biogas production that perform at ambient temperature for 30 days. Ruminant bacteria, yeast, urea, and microalgae was added 10% (v/v, 0.08% (w/v, 0.04% (w/v, 50% (v/v of mixing solution volume, respectively. The pH of slurry was adjusted with range 6.8-7.2 and was measured daily and corrected when necessary with Na2CO3. The total biogas production was measured daily by the water displacement technique. Biogas production from the ungelling and gelling mixture of cassava starch effluent, yeast, ruminant bacteria, and urea were 726.43 ml/g total solid and 198 ml/g total solid. Biogas production from ungelling mixture without yeast was 58.6 ml/g total solid. Biogas production from ungelling mixture added by microalgae without yeast was 58.72 ml/g total solid and that with yeast was 189 ml/g total solid. Biogas production from ungelling mixture of cassava starch effluent, yeast, ruminant bacteria, and urea in semi-continuous process was 581.15 ml/g total solid. Adding of microalgae as nitrogen source did not give significant effect to biogas production. But adding of yeast as substrate activator was very helpful to accelerate biogas production. The biogas production increased after cassava starch effluent and yeast was added. Requirement of sodium carbonate (Na2CO3 to increase alkalinity or buffering capacity of fermenting solution depends on pH-value

  4. Structure and properties of pregelatinized cassava starch/kaolin composites

    International Nuclear Information System (INIS)

    Highlights: ► Pregelatinized starch/kaolin composites were prepared using compression molding. ► The tensile strengths of the composites were higher than for thermoplastic starch. ► Degradation temperatures of the composites were higher than for thermoplastic starch. ► The retrogradation behavior of the composites was hindered by kaolin. -- Abstract: Pregelatinized cassava starch/kaolin composites were prepared using compression molding. The morphology of the fractured surfaces, retrogradation behavior, thermal decomposition temperatures and mechanical properties of the composites were investigated using scanning election microscopy (SEM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA) and tensile testing, respectively. The tensile strengths and thermal degradation temperatures of the composites were higher than for thermoplastic starch (TPS). The retrogradation behavior of the composites was hindered by kaolin. The water absorption was measured after aging for 12 and 45 days at a relative humidity (RH) of 15% and 55%. It indicated that all the composites displayed lower water absorption values than TPS.

  5. Study of cassava starch enzymatic modification for maltodextrins obtention

    Directory of Open Access Journals (Sweden)

    Miguel Angel Díaz

    2012-05-01

    Full Text Available It was pretended to investigate the effect of the most relevant variables in cassava starch enzymatic hydrolysis process, on laboratory scale, to determine appropriate industrial conditions for the obtention of different kinds of maltodextrins. An a-Amylase enzyme, from genetically modified strain of Bacillus lichenijormis, was used to hydrolize the starch. Once the variables were chosen, an experimental fractioned factorial design was established with two levels. The Dextrose Equivalent (DE was taken as the response variable. The variables studied were: temperature (80-90°C, pH (5.5-6.5, dry-weight starch concentration (30-40% w/w, enzyme dosage (0.583-0.833 ul/g starch and calcium concentration (50-70 mgIL of CaClJ Some assays were settle in order to define the rheologic behavior and to determine the most relevant variables that affect the functional properties of the maltodextrin suspensions. Both, temperature and enzyme concentration were the variables that affect the most the initial convertion rate and the characteristics of the product convertion. For the interval of time considered, the highest DE obtained was 30 and the highest initial rate was 21.7 DE/hour. The functional properties of the maltodextrin solutions were affected by temperature and dry-weight starch concentration.

  6. Biological implications in cassava for the production of amylose-free starch: impact on root yield and related traits.

    OpenAIRE

    Amanda eKarlström; Sandra eSalazar; Fernando eCalle; Nelson eMorante; Dominique eDufour; Hernán eCeballos

    2016-01-01

    Cassava (Manihot esculenta, Crantz) is an important food security crop, but it is becoming an important raw material for different industrial applications. Cassava is the second most important source of starch worldwide. Novel starch properties are of interest to the starch industry, and one them is the recently identified amylose-free (waxy) cassava starch. Waxy mutants have been found in different crops and have been often associated with a yield penalty. There are ongoing efforts to develo...

  7. Biological Implications in Cassava for the Production of Amylose-Free Starch: Impact on Root Yield and Related Traits

    OpenAIRE

    Karlström, Amanda; Calle, Fernando; Salazar, Sandra; Morante, Nelson; Dufour, Dominique; Ceballos, Hernán

    2016-01-01

    Cassava (Manihot esculenta, Crantz) is an important food security crop, but it is becoming an important raw material for different industrial applications. Cassava is the second most important source of starch worldwide. Novel starch properties are of interest to the starch industry, and one them is the recently identified amylose-free (waxy) cassava starch. Waxy mutants have been found in different crops and have been often associated with a yield penalty. There are ongoing efforts to develo...

  8. Molecular and supra-molecular structure of waxy starches developed from cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Rolland-Sabaté, Agnès; Sanchez, Teresa; Buléon, Alain; Colonna, Paul; Ceballos, Hernan; Zhao, Shan-Shan; Zhang, Peng; Dufour, Dominique

    2013-02-15

    The aim of this work was to characterize the amylopectin of low amylose content cassava starches obtained from transgenesis comparatively with a natural waxy cassava starch (WXN) discovered recently in CIAT (International Center for Tropical Agriculture). Macromolecular features, starch granule morphology, crystallinity and thermal properties of these starches were determined. M¯(w) of amylopectin from the transgenic varieties are lower than WXN. Branched and debranched chain distributions analyses revealed slight differences in the branching degree and structure of these amylopectins, principally on DP 6-9 and DP>37. For the first time, a deep structural characterization of a series of transgenic lines of waxy cassava was carried out and the link between structural features and the mutated gene expression approached. The transgenesis allows to silenced partially or totally the GBSSI, without changing deeply the starch granule ultrastructure and allows to produce clones with similar amylopectin as parental cassava clone.

  9. Rheological behavior of gamma-irradiated cassava (Manihot esculenta crantz) starch

    International Nuclear Information System (INIS)

    Cassava starch is the by-product of the process of pressing water out of cassava to make cassava meal. The juice has a fine starch, similar to rice or potato starch that, when dried, yields polvilho doce (sweet manioc starch); from the fermented juice comes polvilho azedo (sour manioc starch). Cassava starch can perform most of the functions where maize, rice and wheat starch are currently used. The aim of the present work was to determine the influence or ionizing radiation on the rheological behavior of aqueous preparations of gamma-irradiated cassava starch at different concentrations. Samples of polvilho doce and polvilho azedo were obtained at the local market and irradiated in plastic bags in a Gammacell 220 with doses of 1, 3 e 5 kGy, dose rate ∼ 1.2 kGy h-1. A Brooksfield viscometer was employed for the viscosity measurements. The results showed a strong dependence of the viscosity with the concentration of the starch solutions. In most of the cases there was a decrease of viscosity with the increase of the radiation dose usually seen in irradiated polysaccharides. Nevertheless, the dose response relation of the two kind of starch was different. (author)

  10. Rheological behavior of gamma-irradiated cassava (Manihot esculenta crantz) starch

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Orelio L.; Uehara, Vanessa B.; Mastro, Nelida L. del, E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Cassava starch is the by-product of the process of pressing water out of cassava to make cassava meal. The juice has a fine starch, similar to rice or potato starch that, when dried, yields polvilho doce (sweet manioc starch); from the fermented juice comes polvilho azedo (sour manioc starch). Cassava starch can perform most of the functions where maize, rice and wheat starch are currently used. The aim of the present work was to determine the influence or ionizing radiation on the rheological behavior of aqueous preparations of gamma-irradiated cassava starch at different concentrations. Samples of polvilho doce and polvilho azedo were obtained at the local market and irradiated in plastic bags in a Gammacell 220 with doses of 1, 3 e 5 kGy, dose rate ∼ 1.2 kGy h-1. A Brooksfield viscometer was employed for the viscosity measurements. The results showed a strong dependence of the viscosity with the concentration of the starch solutions. In most of the cases there was a decrease of viscosity with the increase of the radiation dose usually seen in irradiated polysaccharides. Nevertheless, the dose response relation of the two kind of starch was different. (author)

  11. Characteristics of cassava starch fermentation wastewater based on structural degradation of starch granules

    Directory of Open Access Journals (Sweden)

    Juliane Mascarenhas Pereira

    2016-01-01

    Full Text Available ABSTRACT: Sour cassava starch is a naturally modified starch produced by fermentation and sun drying, achieving the property of expansion upon baking. Sour cassava starch' bakery products can be prepared without the addition of yeast and it is gluten free. The fermentation process associated with this product has been well studied, but the wastewater, with high acidity and richness in other organic compounds derived from starch degradation, requires further investigation. In this study, the structure of solids present in this residue was studied, seeking to future applications for new materials. The solids of the wastewater were spray dried with maltodextrin (MD with dextrose equivalent (DE of 5 and 15 and the structure of the powder was evaluated by scanning electron microscopy. A regular structure with a network arrangement was observed for the dried material with MD of 5 DE, in contrast to the original and fermented starches structure, which suggests a regular organization of this new material, to be studied in future applications.

  12. Effect of carboxymethyl cellulose concentration on physical properties of biodegradable cassava starch-based films

    Directory of Open Access Journals (Sweden)

    Sriburi Pensiri

    2011-02-01

    Full Text Available Abstract Background Cassava starch, the economically important agricultural commodity in Thailand, can readily be cast into films. However, the cassava starch film is brittle and weak, leading to inadequate mechanical properties. The properties of starch film can be improved by adding plasticizers and blending with the other biopolymers. Results Cassava starch (5%w/v based films plasticized with glycerol (30 g/100 g starch were characterized with respect to the effect of carboxymethyl cellulose (CMC concentrations (0, 10, 20, 30 and 40%w/w total solid and relative humidity (34 and 54%RH on the mechanical properties of the films. Additionally, intermolecular interactions were determined by Fourier transform infrared spectroscopy (FT-IR, melting temperature by differential scanning calorimetry (DSC, and morphology by scanning electron microscopy (SEM. Water solubility of the films was also determined. Increasing concentration of CMC increased tensile strength, reduced elongation at break, and decreased water solubility of the blended films. FT-IR spectra indicated intermolecular interactions between cassava starch and CMC in blended films by shifting of carboxyl (C = O and OH groups. DSC thermograms and SEM micrographs confirmed homogeneity of cassava starch-CMC films. Conclusion The addition of CMC to the cassava starch films increased tensile strength and reduced elongation at break of the blended films. This was ascribed to the good interaction between cassava starch and CMC. Cassava starch-CMC composite films have the potential to replace conventional packaging, and the films developed in this work are suggested to be suitable for low moisture food and pharmaceutical products.

  13. Effect of waxy rice flour and cassava starch on freeze-thaw stability of rice starch gels.

    Science.gov (United States)

    Charoenrein, Sanguansri; Preechathammawong, Nutsuda

    2012-10-01

    Repeatedly frozen and thawed rice starch gel affects quality. This study investigated how incorporating waxy rice flour (WF) and cassava starch (CS) in rice starch gel affects factors used to measure quality. When rice starch gels containing 0-2% WF and CS were subjected to 5 freeze-thaw cycles, both WF and CS reduced the syneresis in first few cycles. However CS was more effective in reducing syneresis than WF. The different composite arrangement of rice starch with WF or CS caused different mechanisms associated with the rice starch gel retardation of retrogradation, reduced the spongy structure and lowered syneresis. Both swollen granules of rice starch and CS caused an increase in the hardness of the unfrozen and freeze-thawed starch gel while highly swollen WF granules caused softer gels. These results suggested that WF and CS were effective in preserving quality in frozen rice starch based products.

  14. Influence of nanoparticles on the properties of bionanocomposites from cassava starch

    International Nuclear Information System (INIS)

    Plastics are widely used packaging materials for food and non-food products due to their desirable material properties and low cost. However, the merits of plastic products have been overshadowed by its non-degradable nature, thereby leading to waste disposal problems. Because of the environmental problem, many researchers are facing to minimize non-degradable to biodegradable materials. Starch is one of the most promising natural polymers because of its inherent biodegradability, overwhelming abundance and its renewability. One of the abundant starch is cassava. The Manihot exculenta Crantz, is known as camoteng-kahoy or balinghoy in the Philippines. The production of thermoplastic starch (also known as plasticized starch or TPS) basically involves three essential components, namely: starch, plasticizer and thermomechanical energy. However, this material has high water solubility and may lose their mechanical properties in humid conditions. One of the possible ways to overcome this problem is through nanocomposite in which consist of a polymer matrix reinforced with nano-dimensional particles. This research involves the processing of cassava starch into thermoplastic starch for packaging application that can be biodegraded in soil or compostable after its usage. Thermoplastic starchs from cassava starch and different nanomaterials were processed by melt-blending method in a twin-screw extruder. The four nanofillers - nanoclay (NC), halloysite nanotube (HNT), nanozeolite (NZ), and nanocalcium carbonate (NCC) were incorporated into the starch matrix in a 3 phr concentration. The resulting biocomposites were characterized in terms of mechanical properties, morphology, thermal properties, moisture absorption, and crystallinity. The newly developed technology based on cassava starch/nano-scale particles nanocomposites upgrade the hdydrophylic and mechanical properties of starch based films. Homogeneously dispersing nanometer size materials, with high length

  15. Thermal characterization of partially hydrolyzed cassava (Manihot esculenta starch granules

    Directory of Open Access Journals (Sweden)

    Luiz Gustavo Lacerda

    2008-12-01

    Full Text Available Cassava starch, partially hydrolyzed by fungal á-amylase, was characterized using thermal analysis, light microscopy and X-ray diffraction. Thermal degradation was initiated at lower degradation temperatures after enzymatic treatment and the DSC (Differential scanning calorimetry analysis showed almost similar range of gelatinization temperature, but the enthalpies of gelatinization were quite increased for the partially hydrolyzed starch granules. The results suggested that the partial degradation of the starch granules was concentrated in the amorphous regions.Amilases fúngicas são comumente empregadas a amidos com o intuito de otimizar o rendimento de leveduras, modificar a textura de produtos panificados e prolongar a vida de prateleira do produto final. A hidrólise parcial enzimática pode auxiliar no entendimento da estrutura do amido ganular. Amido de mandioca parcialmente hidrolisado por á-amilase fúngica foi investigado utilizando-se técnicas termoanalíticas, microscopia ótica e difratometria por raios X. A degradação térmica iniciou-se a temperaturas menores após o tratamento enzimático e a análise por DSC mostrou uma próxima faixa de temperatura de gelatinização, porém, a entalpia necessária para o evento foi maior para os grânulos parcialmente hidrolisados. Os resultados sugerem que a degradação parcial do amido granular foi concentrada em regiões amorfas.

  16. DEVELOPMENT OF ADHESIVE TO THE BASIS OF CORN AND CASSAVA STARCH

    Directory of Open Access Journals (Sweden)

    Rosane Furtado Fabrício

    2014-05-01

    Full Text Available Corn and native cassava starch were modified by oxidation and acid hydrolysis, aiming to develop paper and paperboard stickers. The oxidation was made with Sodium hypochlorite (NaOCl in two distinct concentrations of active chloride which is present on oxidizing agent solution. The synthesis resulting products were used to make stickers and they were compared to corn and cassava starch based stickers without any modification, as well as commercial stickers based on polyvinyl acetate (PVA. Two different methodologies were tested using acid hydrolysis to modify corn and cassava starch, both using phosphoric acid (H3PO4 in order to obtain dextrin and subsequently use it in the production of stickers and also comparing them to petrochemical-based commercial stickers. Considering the different starch modifications methods (oxidation and acid hydrolysis, stickers based on renewable raw material were obtained, which combine biodegradability, low costs and availability.

  17. Functionality of maize, wheat, teff and cassava starches with stearic acid and xanthan gum.

    Science.gov (United States)

    Maphalla, Thabelang Gladys; Emmambux, Mohammad Naushad

    2016-01-20

    Consumer concerns to synthetic chemicals have led to strong preference for 'clean' label starches. Lipid and hydrocolloids are food friendly chemicals. This study determines the effects of stearic acid and xanthan gum alone and in combination on the functionality of maize, wheat, teff and cassava starches. An increase in viscosity was observed for all starches with stearic acid and xanthan gum compared to the controls with cassava having the least increase. A further increase in viscosity was observed for the cereal starches with combination of stearic acid and xanthan gum. Stearic acid reduced retrogradation, resulting in soft textured pastes. Combination of stearic acid and xanthan gum reduced the formation of type IIb amylose-lipid complexes, syneresis, and hysteresis in cereal starches compared to stearic acid alone. A combination of stearic acid and xanthan gum produce higher viscosity non-gelling starches and xanthan gum addition increases physical stability to freezing and better structural recovery after shear. PMID:26572436

  18. Biological Implications in Cassava for the Production of Amylose-Free Starch: Impact on Root Yield and Related Traits

    Science.gov (United States)

    Karlström, Amanda; Calle, Fernando; Salazar, Sandra; Morante, Nelson; Dufour, Dominique; Ceballos, Hernán

    2016-01-01

    Cassava (Manihot esculenta, Crantz) is an important food security crop, but it is becoming an important raw material for different industrial applications. Cassava is the second most important source of starch worldwide. Novel starch properties are of interest to the starch industry, and one them is the recently identified amylose-free (waxy) cassava starch. Waxy mutants have been found in different crops and have been often associated with a yield penalty. There are ongoing efforts to develop commercial cassava varieties with amylose-free starch. However, little information is available regarding the biological and agronomic implications of starch mutations in cassava, nor in other root and tuber crops. In this study, siblings from eight full-sib families, segregating for the waxy trait, were used to determine if the mutation has implications for yield, dry matter content (DMC) and harvest index in cassava. A total of 87 waxy and 87 wild-type starch genotypes from the eight families were used in the study. The only significant effect of starch type was on DMC (p cassava varieties will have competitive FRYs but special efforts will be required to attain adequate DMCs. This study contributes to the limited knowledge available of the impact of starch mutations on the agronomic performance of root and tuber crops. PMID:27242813

  19. Process optimization for bioethanol production from cassava starch using novel eco-friendly enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Shanavas, S.; Padmaja, G.; Moorthy, S.N.; Sajeev, M.S.; Sheriff, J.T. [Division of Crop Utilization, Central Tuber Crops Research Institute, Thiruvananthapuram, 695 017 Kerala (India)

    2011-02-15

    Although cassava (Manihot esculenta Crantz) is a potential bioethanol crop, high operational costs resulted in a negative energy balance in the earlier processes. The present study aimed at optimizing the bioethanol production from cassava starch using new enzymes like Spezyme {sup registered} Xtra and Stargen trademark 001. The liquefying enzyme Spezyme was optimally active at 90 C and pH 5.5 on a 10% (w/v) starch slurry at levels of 20.0 mg (280 Amylase Activity Units) for 30 min. Stargen levels of 100 mg (45.6 Granular Starch Hydrolyzing Units) were sufficient to almost completely hydrolyze 10% (w/v) starch at room temperature (30 {+-} 1 C). Ethanol yield and fermentation efficiency were very high (533 g/kg and 94.0% respectively) in the Stargen + yeast process with 10% (w/v) starch for 48 h. Raising Spezyme and Stargen levels to 560 AAU and 91.2 GSHU respectively for a two step loading [initial 20% (w/v) followed by 20% starch after Spezyme thinning]/initial higher loading of starch (40% w/v) resulted in poor fermentation efficiency. Upscaling experiments using 1.0 kg starch showed that Stargen to starch ratio of 1:100 (w/w) could yield around 558 g ethanol/kg starch, with a high fermentation efficiency of 98.4%. The study showed that Spezyme level beyond 20.0 mg for a 10% (w/v) starch slurry was not critical for optimizing bioethanol yield from cassava starch, although an initial thinning of starch for 30 min by Spezyme facilitated rapid saccharification-fermentation by Stargen + yeast system. The specific advantage of the new process was that the reaction could be completed within 48.5 h at 30 {+-} 1 C. (author)

  20. Post-harvest conservation of organic strawberries coated with cassava starch and chitosan

    Directory of Open Access Journals (Sweden)

    Raquel P Campos

    2011-10-01

    Full Text Available The strawberry is as non-climacteric fruit, but has a high post-harvest respiration rate, which leads to a rapid deterioration at room temperature. This study aimed to evaluate the application of biodegradable coating on postharvest conservation of organic strawberries, cv. Camarosa, packed in plastic hinged boxes and stored at 10ºC. The treatments consisted of: a control; b 2% cassava starch; c 1% chitosan; and d 2% cassava starch + 1% chitosan. Physical and chemical characteristics of fruits were evaluated at 3, 6 and 9 days of storage, and microbiological and sensory analyses were carried out at the end of the storage period. The treatments influenced positively the post-harvest quality of organic strawberries. The coating cassava starch + chitosan provided the best results, with less than 6% of loss in fruit mass, lower counts of yeast and psychrophilic microorganisms and the best appearance according to the sensory analysis.

  1. Thin layer drying of cassava starch using continuous vibrated fluidized bed dryer

    Science.gov (United States)

    Suherman, Trisnaningtyas, Rona

    2015-12-01

    This paper present the experimental work and thin layer modelling of cassava starch drying in continuous vibrated fluidized bed dryer. The experimental data was used to validate nine thin layer models of drying curve. Cassava starch with 0.21 initial moisture content was dried in different air drying temperature (50°C, 55°C, 60°C, 65°C, 70°C), different weir height in bed (0 and 1 cm), and different solid feed flow (10 and 30 gr.minute-1). The result showed air dryer temperature has a significant effect on drying curve, while the weir height and solid flow rate are slightly. Based on value of R2, χ2, and RMSE, Page Model is the most accurate simulation for thin layer drying model of cassava starch.

  2. Morphology and structural properties of high-amylose rice starch residues hydrolysed by amyloglucosidase.

    Science.gov (United States)

    Man, Jianmin; Yang, Yang; Huang, Jun; Zhang, Changquan; Zhang, Fengmin; Wang, Youping; Gu, Minghong; Liu, Qiaoquan; Wei, Cunxu

    2013-06-15

    High-amylose starches are attracting considerable attention because of their potential health benefits and industrial uses. Enzyme hydrolysis of starch is involved in many biological and industrial processes. In this paper, starches were isolated from high-amylose transgenic rice (TRS) and its wild type rice, Te-qing (TQ). The morphological and structural changes of starch residues following Aspergillus niger amyloglucosidase (AAG) hydrolysis were investigated. AAG hydrolysed TQ starch from the granule surface, and TRS starch from the granule interior. During AAG hydrolysis, the content of amorphous structure increased, the contents of ordered structure and single helix decreased, and gelatinisation enthalpy decreased in TQ and TRS starch residues. The A-type polymorph of TRS C-type starch was hydrolysed faster than the B-type polymorph. The short-range ordered structure and B-type polymorph in the peripheral region of the subgranule and the surrounding band of TRS starch increased the resistance of TRS starch to AAG hydrolysis. PMID:23497862

  3. Ozone oxidation of cassava starch in aqueous solution at different pH.

    Science.gov (United States)

    Klein, Bruna; Vanier, Nathan Levien; Moomand, Khalid; Pinto, Vânia Zanella; Colussi, Rosana; da Rosa Zavareze, Elessandra; Dias, Alvaro Renato Guerra

    2014-07-15

    Ozone is a more powerful oxidant than common oxidising agents, such as sodium hypochlorite and hydrogen peroxide. It is considered as a safer starch modification method for both consumers and the environment. However, few studies have investigated the changes in starch properties associated with ozone treatment, particularly when applied in aqueous solution. This work aimed to evaluate the carbonyl and carboxyl contents, the X-ray diffraction patterns, the spectrum profiles of Fourier transform infrared spectroscopy, the pasting properties and the surface morphology of ozone-oxidised cassava starch during 60 min under different pH (3.5, 6.5 and 9.5) at 25°C. The pH 6.5 and 9.5 seemed to favour the cross-linking between the depolymerised starch molecules during ozonation. The pH 3.5 was more effective in reducing the peak viscosity, breakdown, setback and final viscosity of cassava starch during ozonation in aqueous solution. No differences in the granule surface morphology were observed in the ozone-treated cassava starches compared to native starch.

  4. Effects of Radiation on Mechanical Properties of Poly (butylene succinate) and Cassava Starch Blends

    International Nuclear Information System (INIS)

    This research compared the effects of gamma and electron beam irradiation at different doses on the mechanical properties of polymer blends between poly(butylene succinate) (PBS) and cassava starch. Two types of starch were used to prepare thermoplastic starch (TPS), native cassava starch and hydrophobic starch. PBS/TPS blends were compounded at five different weight ratios using a twin-screw extruder. Mechanical properties and degradation were evaluated in comparison to unirradiated samples. Results indicated that the incorpora- tion of TPS prepared from native cassava starch decreased the mechanical properties of PBS/TPS blends, whereas the addition of TPS prepared from hydrophobic starch improved the mechanical properties of the blends. In addition, the maximum mechanical properties of PBS/TPS blends were achieved when samples were exposed to irradiation at 120 kGy. Using soil burial evaluation, the degradation rate of blends was found to increase with the addition of TPS. Therefore we have demonstrated in this study that the type of TPS and irradiation treatment can significantly alter the mechanical properties and degradation of PBS/TPS blends.

  5. Production of pullulan from raw potato starch hydrolysates by a new strain of Auerobasidium pullulans.

    Science.gov (United States)

    Wu, Shengjun; Lu, Mingsheng; Chen, Jing; Fang, Yaowei; Wu, Leilei; Xu, Yan; Wang, Shujun

    2016-01-01

    In the present study, hydrolysis of potato starch with marine cold-adapted α-amylase and pullulan production from the hydrolysates by a new strain of Auerobasidium pullulans isolated from sea mud were conducted. The hydrolysis conditions were optimized as follows: reaction time 2h, pH 6.5, temperature 20°C, and α-amylase amount 12 U/g. Under these optimum hydrolysis conditions, the DE value of the potato starch hydrolysates reached to 49.56. The potato starch hydrolysates consist of glucose, maltose, isomaltose, maltotriose, and trace of other maltooligosaccharides with degree of polymerization ranged 4-7. The maximum production of pullulan at 96 h from the hydrolysate of potato starch was 36.17 g/L, which was higher than those obtained from glucose (22.07 g/L, p<0.05) and sucrose (31.42 g/L, p<0.05). Analysis of the high performance liquid chromatography of the hydrolysates of the pullulan product with pullulanase indicated that the main composition is maltotriose, thus confirming the pullulan structure of this pullulan product.

  6. Biodegradable foam trays obtained from mixtures of non-irradiated and irradiated cassava starches

    International Nuclear Information System (INIS)

    Biodegradable polymers, such as starch, cellulose, PHB, PLA, and derivatives thereof, are being studied to produce innovative packaging in the most diverse shapes (films, bags, trays, bottles, etc.) to attend this current market trend. The aim of this work was to produce foam trays from cassava starch for food packaging by extrusion-thermopressing process. Their formulations were based on non-irradiated and γ-irradiated starches at diverse radiation absorbed doses (kGy) in order to evaluate the influence of the irradiated starches on the physical properties of the trays. Water absorption results showed an irregular increase with the increase of the absorbed dose: 26.32% and 39.84% for the trays based on starch 0 kGy and 1:1 (w/w) mixture of starches 0 kGy and 100.0 kGy, respectively. Other physicochemical properties were evaluated from the starches utilized and the trays obtained. (author)

  7. Biodegradable foam trays obtained from mixtures of non-irradiated and irradiated cassava starches

    Energy Technology Data Exchange (ETDEWEB)

    Brant, A.J.C.; Naime, N.; Lugao, A.B.; Ponce, P., E-mail: thonybrant@gmail.com, E-mail: patiponce@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Biodegradable polymers, such as starch, cellulose, PHB, PLA, and derivatives thereof, are being studied to produce innovative packaging in the most diverse shapes (films, bags, trays, bottles, etc.) to attend this current market trend. The aim of this work was to produce foam trays from cassava starch for food packaging by extrusion-thermopressing process. Their formulations were based on non-irradiated and γ-irradiated starches at diverse radiation absorbed doses (kGy) in order to evaluate the influence of the irradiated starches on the physical properties of the trays. Water absorption results showed an irregular increase with the increase of the absorbed dose: 26.32% and 39.84% for the trays based on starch 0 kGy and 1:1 (w/w) mixture of starches 0 kGy and 100.0 kGy, respectively. Other physicochemical properties were evaluated from the starches utilized and the trays obtained. (author)

  8. Radiation modification of water absorption of cassava starch by acrylic acid/acrylamide

    International Nuclear Information System (INIS)

    Graft co polymerizations of acrylamide and/or acrylic acid onto cassava starch by a simultaneous irradiation technique using gamma-rays as the initiator were studied with regard to various parameters of importance: the monomer-to-cassava starch ratio, total dose (kGy), dose rate (kGy h-1), acrylamide-to-acrylic acid ratio, and the addition of nitric acid and maleic acid as the additives. Grafting parameters were determined in relation to the water absorption of the saponified graft copolymer. The water absorption of the saponified graft copolymer in salt and buffer solutions of different ionic strengths was also measured, from which the super absorbent properties are found to be P H sensitive. The starch graft copolymers of acrylamide and acrylic acid give higher water absorption than the starch graft copolymers of either acrylamide or acrylic acid alone. The porosity of the saponified starch graft copolymers prepared by the acrylamide/acrylic acid ratios of 70:30 and 50:50 was much higher than the porosity of copolymers in terms of fine networks. Ionic strength and multi-oxidation states of the saline and buffer solutions markedly decreased the water absorption of the saponified cassava starch grafted super absorbent polymers.

  9. Structural and Digestion Properties of Soluble-, Slowly Digestible and Resistant Maltodextrin from Cassava Starch by Enzymatic Modification

    DEFF Research Database (Denmark)

    Sorndech, Waraporn

    The combination of branching enzyme (BE) and amylomaltase (AM) were selected to modify cassava starch. AM were used to elongate the glucan chains in order to enhance BE activity to create branching linkages. Cassava starch were gelatinized and incubated with BE or AMBE or BEAMBE or simultaneous......) production was prepared by using simultaneous α-amylase and BE followed by α- transglucosidase (ABT) and simultaneous α-amylase and BE followed by simultaneous β-amylase and α-transglucosidase (ABbT) with 30% and 50% (w/v) cassava starch substrate concentration. ABT catalysis showed branching linkages...

  10. Exploratory studies on the carboxymethylation of cassava starch in water-miscible organic media

    NARCIS (Netherlands)

    Yao, J; Chen, WR; Manurung, RM; Ganzeveld, KJ; Heeres, HJ; Manurung, Robbert M.; Chen, Wen-ren

    2004-01-01

    The carboxymethylation of cassava starch using sodium monochloroacetate (SMCA) as an etherification agent was investigated. Mixtures of water and water-miscible organic liquids were selected as carboxymethylation reaction medium to obtain a high degree of substitution (DS) without changing the granu

  11. Preparation and physico-chemical properties of hydrogels from carboxymethyl cassava starch crosslinked with citric acid

    Science.gov (United States)

    Boonkham, Sasikan; Sangseethong, Kunruedee; Chatakanon, Pathama; Niamnuy, Chalida; Nakasaki, Kiyohiko; Sriroth, Klanarong

    2014-06-01

    Recently, environmentally friendly hydrogels prepared from renewable bio-based resources have drawn significant attention from both industrial and academic sectors. In this study, chemically crosslinked hydrogels have been developed from cassava starch which is a bio-based polymer using a non-toxic citric acid as a crosslinking agent. Cassava starch was first modified by carboxymethylation to improve its water absorbency property. The carboxymethyl cassava starch (CMCS) obtained was then crosslinked with citric acid at different concentrations and reaction times. The gel fraction of hydrogels increased progressively with increasing citric acid concentration. Free swelling capacity of hydrogels in de-ionized water, saline solution and buffers at various pHs as well as absorption under load were investigated. The results revealed that swelling behavior and mechanical characteristic of hydrogels depended on the citric acid concentration used in reaction. Increasing citric acid concentration resulted in hydrogels with stronger network but lower swelling and absorption capacity. The cassava starch hydrogels developed were sensitive to ionic strength and pH of surrounding medium, showing much reduced swelling capacity in saline salt solution and acidic buffers.

  12. Stoking residue from extraction of cassava starch without the use of storage technologies

    Directory of Open Access Journals (Sweden)

    Cleovani Rossi Javorski

    2015-03-01

    Full Text Available The purpose of this paper was to study the storage of the residue from the extraction of cassava starch without the use of storage technologies, through chemical evaluation, pH values, temperature, development of microorganisms and mycotoxins. A randomized block design was used with eight treatments (different storage periods: 0, 3, 6, 9, 12, 15, 18 and 21 days and five replications. There was a significant difference for DM content, as a function of days in storage. The chemical composition of the residue from the extraction of cassava starch did not changed throughout the storage period. A negative linear effect was obtained for the pH values, which decreased with days in storage. There was significance of the storage period only for the fungus and yeast population, which increased up to 17 days of storage, with subsequent reduction. Mycotoxins were detected in the residue from the extraction of cassava starch. Despite it did not showed changes in the chemical composition the storage of residue from the extraction of cassava starch for 21 days proved to be an inefficient preservation process, due to the development of molds and mycotoxins

  13. EFFECTS OF INGREDIENTS AND EXTRUSION PARAMETERS ON AQUAFEEDS CONTAINING DDGS AND CASSAVA STARCH

    Science.gov (United States)

    Twenty seven isocaloric (3.05 kcal/g) ingredient blends were factorially formulated using three levels each of DDGS (20, 25, and 30% db), protein (30, 32.5, and 35% db), and feed moisture content (25, 35, and 45% db), along with appropriate quantities of cassava starch, soybean meal, fish meal, whey...

  14. Biological Implications in Cassava for the Production of Amylose-Free Starch: Impact on Root Yield and Related Traits.

    Science.gov (United States)

    Karlström, Amanda; Calle, Fernando; Salazar, Sandra; Morante, Nelson; Dufour, Dominique; Ceballos, Hernán

    2016-01-01

    Cassava (Manihot esculenta, Crantz) is an important food security crop, but it is becoming an important raw material for different industrial applications. Cassava is the second most important source of starch worldwide. Novel starch properties are of interest to the starch industry, and one them is the recently identified amylose-free (waxy) cassava starch. Waxy mutants have been found in different crops and have been often associated with a yield penalty. There are ongoing efforts to develop commercial cassava varieties with amylose-free starch. However, little information is available regarding the biological and agronomic implications of starch mutations in cassava, nor in other root and tuber crops. In this study, siblings from eight full-sib families, segregating for the waxy trait, were used to determine if the mutation has implications for yield, dry matter content (DMC) and harvest index in cassava. A total of 87 waxy and 87 wild-type starch genotypes from the eight families were used in the study. The only significant effect of starch type was on DMC (p < 0.01), with waxy clones having a 0.8% lower content than their wild type counterparts. There was no effect of starch type on fresh root yield (FRY), adjusted FRY and harvest index. It is not clear if lower DMC is a pleiotropic effect of the waxy starch mutation or else the result of linked genes introgressed along with the mutation. It is expected that commercial waxy cassava varieties will have competitive FRYs but special efforts will be required to attain adequate DMCs. This study contributes to the limited knowledge available of the impact of starch mutations on the agronomic performance of root and tuber crops. PMID:27242813

  15. Effect of acid additives on grafting efficiency and water absorption of hydrolyzed cassava starch grafted polymers

    International Nuclear Information System (INIS)

    Gelatinized cassava starch was radiation graft copolymerized with acrylamide, acrylic acid or their mixture in the presence of sulphuric acid or maleic acid. Various acid concentrations were used from 0.001 to 0.1 M of sulphuric acid while the maleic acid concentrations were varied from 1 to 3% (by weight). The optimum total dose and dose rate were investigated. The saponification temperature and time had the marked effects on grafting characteristics and water absorption capacity. We found that the effect of maleic acid addition gave a profound effect on water absorption. The CHNS/O analyses indicated significant changes in the nitrogen content in the hydrolyzed starch grafted polyacrylamide with 2% maleic acid. The article explains the possible causes for the enhancement influence of mineral acid and maleic acid on grafting behavior and water absorption of the saponified cassava starch grafted polyacrylamide super absorbent polymer. (author)

  16. Gamma irradiation effect on mechanical and barrier properties of foamed articles based on cassava starch

    International Nuclear Information System (INIS)

    With the increasing environmental concern, replacing the traditional non-biodegradable synthetic materials for biodegradable products is the challenge for many researchers and companies. Starch is considered one of the most promising natural polymers for packaging application because of its renewability, biodegradability and low cost. However, there are some limitations in developing starch-based products due to its poor mechanical properties and high moisture sensitivity. These properties can change when subjected to any process of sterilization, especially by gamma radiation. This work aims to study the mechanical and barrier properties of cassava starch in front of gamma radiation, for cobalt-60 (60C0), when subjected to doses of 3 kGy, 6 kGy, 12 kGy and 25 kGy for the development of packaging, and then it compares the results to those of conventional packaging, as the expanded polystyrene (styrofoam) and paper cards. The starch foams (packaging) were obtained by thermopressing process. After baking, the foams were conditioned for one month at 23 deg C and 60% relative humidity (RH) before mechanical and barrier testing. Polyethyleneglycol (PEG 300) was selected as plasticizer. The packaging in which the cassava starch was subjected to irradiation had higher resistance to compression and higher flexibility compared to that in which the starch had not been irradiated. The expanded polystyrene and paper card packages are less resistant to compression than the cassava starch packages. The styrofoam is more flexible than the paper cards, which in turn is more flexible than packages of starch. After irradiation, the barrier properties of the foams were improved. (author)

  17. Gamma irradiation effect on mechanical and barrier properties of foamed articles based on cassava starch

    Energy Technology Data Exchange (ETDEWEB)

    Naime, Natalia; Ponce, Patricia; Lugao, Ademar B., E-mail: nnaime@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    With the increasing environmental concern, replacing the traditional non-biodegradable synthetic materials for biodegradable products is the challenge for many researchers and companies. Starch is considered one of the most promising natural polymers for packaging application because of its renewability, biodegradability and low cost. However, there are some limitations in developing starch-based products due to its poor mechanical properties and high moisture sensitivity. These properties can change when subjected to any process of sterilization, especially by gamma radiation. This work aims to study the mechanical and barrier properties of cassava starch in front of gamma radiation, for cobalt-60 ({sup 60}C0), when subjected to doses of 3 kGy, 6 kGy, 12 kGy and 25 kGy for the development of packaging, and then it compares the results to those of conventional packaging, as the expanded polystyrene (styrofoam) and paper cards. The starch foams (packaging) were obtained by thermopressing process. After baking, the foams were conditioned for one month at 23 deg C and 60% relative humidity (RH) before mechanical and barrier testing. Polyethyleneglycol (PEG 300) was selected as plasticizer. The packaging in which the cassava starch was subjected to irradiation had higher resistance to compression and higher flexibility compared to that in which the starch had not been irradiated. The expanded polystyrene and paper card packages are less resistant to compression than the cassava starch packages. The styrofoam is more flexible than the paper cards, which in turn is more flexible than packages of starch. After irradiation, the barrier properties of the foams were improved. (author)

  18. Physical characteristics of extruded cassava starch Características físicas de amido de mandioca extrusado

    OpenAIRE

    Magali Leonel; Taila Santos de Freitas; Martha Maria Mischan

    2009-01-01

    Considering the importance of cassava starch for Brazilian industries, the current work aimed at evaluating the effects of extrusion parameters on the physical characteristics, mainly viscosity properties of extruded cassava starch. A factorial central composite design (2³) with three independent variables and the response surface methodology were used to evaluate the results of expansion index, specific volume, water absorption index, water solubility index, color and paste properties, accor...

  19. Preparation of linear maltodextrins using a hyperthermophilic amylopullulanase with cyclodextrin- and starch-hydrolysing activities.

    Science.gov (United States)

    Li, Xiaolei; Li, Dan

    2015-03-30

    A novel method for the preparation of linear maltodextrins from cyclodextrins and starch was proposed. To accomplish this process, an amylopullulanase from hyperthermophilic archaeon Caldivirga maquilingensis (CMApu) was characterized and used. CMApu with an estimated molecular mass of 62.7 kDa by SDS-PAGE had a maximal pullulan-hydrolysing activity at 100°C and pH 5.0. It could also hydrolyse amylopectin (AP), starch, β-CD and amylose (AM), in a decreasing order of relative activities from 88.96% to 57.17%. TLC and HPAEC analysis revealed that CMApu catalyzed the debranching and degrading reactions to produce linear malto-oligosaccharides (≤ G8-G1) from G8-β-CD and/or normal CDs, amylodextrins (DP6-96) from AM, and amylodextrins (DP1-76) from AP and potato starch. Our results showed that CMApu had a great potential for the industrial preparation of linear maltodextrins from normal starch instead of waxy starch, malto-oligosaccharides or sucrose. And the high optimal temperature of CMApu facilitated the simultaneous gelatinization and hydrolysis of cereal starch.

  20. Comparison of pasting and gel stabilities of waxy and normal starches from potato, maize, and rice with those of a novel waxy cassava starch under thermal, chemical, and mechanical stress.

    Science.gov (United States)

    Sánchez, Teresa; Dufour, Dominique; Moreno, Isabel Ximena; Ceballos, Hernán

    2010-04-28

    Functional properties of normal and waxy starches from maize, rice, potato, and cassava as well as the modified waxy maize starch COLFLO 67 were compared. The main objective of this study is to position the recently discovered spontaneous mutation for amylose-free cassava starch in relation to the other starches with well-known characteristics. Paste clarity, wavelength of maximum absorption (lambda(max)), pasting properties, swelling power, solubility, and dispersed volume fraction measurements and gel stability (acid and alkaline resistance, shear, refrigeration, and freeze/thaw stability) were evaluated in the different types and sources of starch included in this study. lambda(max) in the waxy cassava starch was reduced considerably in comparison with that of normal cassava starch (535 vs 592 nm). RVA peak viscosity of waxy cassava starch was larger than in normal cassava starch (1119 vs 937 cP) and assumed a position intermediate between the waxy potato and maize starches. Acid, alkaline, and shear stability of waxy cassava starch were similar to normal cassava except for alkaline pH, at which it showed a low effect. Gels from normal root and tuber starches after refrigeration and freeze/thaw had lower syneresis than cereal starches. Gels from waxy starches (except for potato) did not present any syneresis after 5 weeks of storage at 4 degrees C. Waxy cassava starch was the only one not showing any syneresis after 5 weeks of storage at -20 degrees C. Natural waxy cassava starch is, therefore, a promising ingredient to formulate refrigerated or frozen food.

  1. Enzymatically hydrolysed, acetylated and dually modified corn starch: physico-chemical, rheological and nutritional properties and effects on cake quality.

    Science.gov (United States)

    Sahnoun, Mouna; Ismail, Nouha; Kammoun, Radhouane

    2016-01-01

    Corn starch was treated by enzymatic hydrolysis with Aspergillus oryzae S2 α-amylase, acetylation with vinyl acetate, and dual modification. The dual modified starch displayed a higher substitution degree than the acetylated starch and lower reducing sugar content than the hydrolysed starch. The results revealed that the cooling viscosity and amylose content of those products decrease (P oil absorption capacity was observed for the acetylated starch and, which was less pronounced for the enzymatically hydrolysed starch but more pronounced for the enzymatically hydrolysed acetylated product. The latter product underwent an increase in resistant starch content, which is induced by a rise in hydrolysis time to attain about 67 % after 1 h of reaction. The modified starch samples were added to cake formulations at 5 and 10 % concentrations on a wheat flour basis and compared to native starch. The results revealed that when applied at 5 % concentrations, the modified starches reduced the hardness, cohesion, adhesion and chewiness of baked cakes and enhanced their elasticity, volume, height, crust color, and appearance as compared to native starch. These effects were more pronounced for the cake incorporating the dually modified starch. PMID:26787967

  2. Poly(Lactic Acid Filled with Cassava Starch-g-Soybean Oil Maleate

    Directory of Open Access Journals (Sweden)

    Nopparut Kiangkitiwan

    2013-01-01

    Full Text Available Poly(lactic acid, PLA, is a biodegradable polymer, but its applications are limited by its high cost and relatively poorer properties when compared to petroleum-based plastics. The addition of starch powder into PLA is one of the most promising efforts because starch is an abundant and cheap biopolymer. However, the challenge is the major problem associated with poor interfacial adhesion between the hydrophilic starch granules and the hydrophobic PLA, leading to poorer mechanical properties. In this paper, soybean oil maleate (SOMA was synthesized by grafting soybean oil with various weight percents of maleic anhydride (MA using dicumyl peroxide (DCP as an initiator. Then, SOMA was employed for the surface modifying of cassava starch powder, resulting in SOMA-g-STARCH. The obtained SOMA-g-STARCH was mixed with PLA in various weight ratios using twin-screw extruder, resulting in PLA/SOMA-g-STARCH. Finally, the obtained PLA/SOMA-g-STARCH composites were prepared by a compression molding machines. The compatibility, thermal properties, morphology properties, and mechanical properties were characterized and evaluated. The results showed that the compatibility, surface appearance, and mechanical properties at 90 : 10 and 80 : 20 ratios of PLA/SOMA-g-STARCH were the best.

  3. Cassava Starch Edible Film Incorporated with Lemongrass Oil: Characteristics and Application

    Directory of Open Access Journals (Sweden)

    Muhammad Dani Supardan

    2016-04-01

    Full Text Available The objective of this research is to evaluate the effect of the addition of lemongrass essential oil (LGO on the characteristics and antimicrobial properties of cassava starch based films. Edible films were prepared from a mixture of cassava starch and glycerol. LGO was added to edible films as natural antimicrobial agent. There was a reduction in tensile strength of edible film because of incorporation of LGO. The presence of LGO also caused to a reduction in roughness of the edible film. The experimental results showed that Trichoderma and Penicillium was not appear upon the film until the third day of incubation. Meanwhile, the use of edible films containing LGO as antimicrobial agents caused to a reduction in microbial counts of meat during storage.

  4. Preparation of metal adsorbent from poly(methyl acrylate)-grafted-cassava starch via gamma irradiation

    Science.gov (United States)

    Suwanmala, Phiriyatorn; Hemvichian, Kasinee; Hoshina, Hiroyuki; Srinuttrakul, Wannee; Seko, Noriaki

    2012-08-01

    Metal adsorbent containing hydroxamic acid groups was successfully synthesized by radiation-induced graft copolymerization of methyl acrylate (MA) onto cassava starch. The optimum conditions for grafting were studied in terms of % degree of grafting (Dg). Conversion of the ester groups present in poly(methyl acrylate)-grafted-cassava starch copolymer into hydroxamic acid was carried out by treatment with hydroxylamine (HA) in the presence of alkaline solution. The maximum percentage conversion of the ester groups of the grafted copolymer, % Dg=191 (7.63 mmol/g of MA), into the hydroxamic groups was 70% (5.35 mmol/g of MA) at the optimum condition. The adsorbent of 191%Dg had total adsorption capacities of 2.6, 1.46, 1.36, 1.15 and 1.6 mmol/g-adsorbent for Cd2+, Al3+, UO22+, V5+ and Pb2+, respectively, in the batch mode adsorption.

  5. Polymeric flocculant based on cassava starch grafted polydiallyldimethylammonium chloride: Flocculation behavior and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Razali, M.A.A.; Ariffin, A., E-mail: srazlan@usm.my

    2015-10-01

    Graphical abstract: - Highlights: • Flocculation performance of cassava grafted polyDADMAC was studied. • Turbidity and TSS removal increased with increasing grafting percentage. • The grafted polymer showed good removal in acidic and neutral region. • Zeta potential results pointed to the charge neutralization mechanism. • Flocs increased with increasing grafting percentage and molecular weight. - Abstract: In this work, flocculation properties of cassava starch grafted polydiallyldimethylammonium chloride (polyDADMAC) with different grafting percentages were investigated. Flocculation performance was evaluated in simulated kaolin suspension. The grafting percentages used were 1.76 %, 14.84 %, and 21.98 %. The effectiveness of the flocculation was measured based on the reduction of the turbidity and total suspended solids (TSSs), zeta potential measurements, particle size, and atomic force microscopy imaging. Grafted polymers improved the removal rate of turbidity and TSS compared with gelatinized starch, and the removal rate increased with increasing grafting percentage and dosage.

  6. Super absorbent Prepared by Radiation Induced Graft Copolymerization of Acrylic Acid onto Cassava Starch

    International Nuclear Information System (INIS)

    Full text: Super absorbent was synthesized by radiation-induced graft polymerization of acrylic acid onto cassava starch. Parameters such as the absorbed dose and the amount of monomer were investigated in order to determine the optimum conditions for the grafting polymerization. Water retention, germination percentage and germination energy were determined in order to evaluate the possibility of super absorbent in agricultural applications, especially in arid regions. The graft copolymer was characterized by FTIR. Results indicated that the sand mixed with 0.1%wt super absorbent can absorb more water than the sand without super absorbent. The germination energy of corn seeds mixed with 0.5% super absorbent was obviously higher than those without super absorbent. These experimental results showed that the super absorbent has considerable effect on seed germination and the growth of young plants. Keywords: Super absorbent, Radiation, Acrylic acid, Cassava starch

  7. Polymeric flocculant based on cassava starch grafted polydiallyldimethylammonium chloride: Flocculation behavior and mechanism

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Flocculation performance of cassava grafted polyDADMAC was studied. • Turbidity and TSS removal increased with increasing grafting percentage. • The grafted polymer showed good removal in acidic and neutral region. • Zeta potential results pointed to the charge neutralization mechanism. • Flocs increased with increasing grafting percentage and molecular weight. - Abstract: In this work, flocculation properties of cassava starch grafted polydiallyldimethylammonium chloride (polyDADMAC) with different grafting percentages were investigated. Flocculation performance was evaluated in simulated kaolin suspension. The grafting percentages used were 1.76 %, 14.84 %, and 21.98 %. The effectiveness of the flocculation was measured based on the reduction of the turbidity and total suspended solids (TSSs), zeta potential measurements, particle size, and atomic force microscopy imaging. Grafted polymers improved the removal rate of turbidity and TSS compared with gelatinized starch, and the removal rate increased with increasing grafting percentage and dosage

  8. Optimization of single-cell-protein production from cassava starch using Schwanniomyces castellii.

    Science.gov (United States)

    Hongpattarakere, T; H-Kittikun, A

    1995-11-01

    Schwanniomyces castellii B5285 grew faster and produced greater biomass and higher protein yield than either S. alluvius ATCC 26074 or S. alluvius 81Y when these amylolytic yeasts were grown with 2% (w/v) cassava starch as sole C source. With 0.5% (w/v) glutamate as N source, S. castellii reached 7.12 g cell dry mass/l, with a protein yield of 6.4 g/100 g starch. The optimal agitation speed, aeration rate and pH for growth of this yeast in a fermenter were 400 rev/min, 1.67 vol./vol.min. and 5.0, respectively. Tween 80 at 0.1% increased cell dry mass to 8.90 g/l, cell yield to 44 g/100 g starch and protein yield to 7.4 g/100 g starch.

  9. Characterization of foams obtained from cassava starch, cellulose fibres and dolomitic limestone by a thermopressing process

    OpenAIRE

    Vivian Consuelo Reolon Schmidt; João Borges Laurindo

    2010-01-01

    Cassava starch, dolomitic limestone and eucalypt cellulose fibres were used to prepare foam trays that could be used to pack foodstuffs. The influence of the cellulose fibre concentration in the composite formulation was investigated using 5, 10, 15, 20, 30 and 40% of fibres. The results indicated that an increase in cellulose fibre concentration promoted a decrease in density and tensile strength of the foam samples. The tensile strength at break for foam trays containing 5% of cellulose fib...

  10. Changes in physical properties of extruded sour cassava starch and quinoa flour blend snacks

    OpenAIRE

    Lívia Giolo Taverna; Magali Leonel; Martha Maria Mischan

    2012-01-01

    Given the broad acceptance of sour cassava starch biscuits in Brazil and the nutritional quality of quinoa flour, this study aimed to evaluate the effect of extrusion temperature, screw speed, moisture, and amount of quinoa flour on the physical properties of puffed snacks. Extrusion process was carried out using a single-screw extruder in a factorial central composite design with four factors. Effects of moisture and amount of quinoa flour on the expansion index and specific volume of snacks...

  11. Performance of Cassava Starch as a Proton Exchange Membrane in a Dual Chambered Microbial Fuel Cell.

    Directory of Open Access Journals (Sweden)

    Livinus A. Obasi

    2012-01-01

    Full Text Available This research work shows the feasibility of power generation in a mediatorless dual chambered microbial fuel cell, utilizing cassava starch as the proton exchange membrane (PEM. The study employed swine house effluent (a serious environmental threat as the substrate (fuel (pH, 7.2, BOD: 1200mg/l, COD: 3800mg/l in the anode chamber prepared with a phosphate buffer solution (K2HPO4+KH2PO4, potassium ferry cyanide solution served as the oxygen acceptor in the cathode chamber using graphite electrodes, the cell operating at room temperature (27 ± 30C. The PEM (gelatinized cassava starch was prepared with varying degrees of modifications for three cells, ranging from the untreated pure starch (A, starch treated with 5.9% sodium chloride (B and starch modified with sodium alginate (a gum and activated carbon (C. The open circuit voltages (OCV and powerperformances of the three cells were monitored for ten days. Each of the cells was inoculated with the adopted consortium in soil solution obtained from mangrove forest. The maximum power outputs from the cells were 945.69mW/m2, 1068.54 mW/m2 and 570.83 mW/m2 for A, B and C respectively.

  12. Utilization of Cassava Starch in Copolymerisation of Superabsorbent Polymer Composite (SAPC

    Directory of Open Access Journals (Sweden)

    Akhmad Zainal Abidin

    2014-09-01

    Full Text Available Cassava starch was used as the main chain in the copolymerization of a superabsorbent polymer composite (SAPC based on acrylic acid and bentonite. The SAPC was synthesized through graft polymerization using nano-sized bentonite as reinforcement. The variables in this experiment were: bentonite concentration, acrylic acid to starch weight ratio, concentration of initiator, and cross linker. The product was characterized using FTIR, SEM and TGA-DSC. The results show that the polymerization reactions involved processes of incorporating starch chains as polymer backbone and grafting acrylic acid monomers onto it. The use of cassava starch in the polymerisation produced a very short reaction time (10-15 minutes, which led to SAPC production with higher efficiency and lower cost. Bentonite interacts with monomers via hydrogen and weak bonding, thus improving the thermal properties of the product. The maximum absorbance capacity obtained was at an acrylic acid to starch weight ratio of 5 and a concentration of initiator, cross linker and bentonite of 0.5, 0.05 and 2 weight percent, respectively. The product is suitable for agricultural and medical applications as well as common superabsorbent polymer applications.

  13. Effect of lactic acid and UV irradiation on the cassava and corn starches

    Directory of Open Access Journals (Sweden)

    Célia Maria Landi Franco

    2010-04-01

    Full Text Available In this work, the effect of lactic acid and UV irradiation on the physicochemical and structural characteristics of cassava and corn starches was evaluated. Only the modified cassava starch presented baking expansion capacity. From RVA, reduction of viscosity values, greater internal stability and none set back for modified cassava starch were observed. Modified corn starch did not show any peak viscosity. There were no significant differences in DSC thermal properties of treated and native starches. Amylopectin and amylose molecules from both the modified starches displayed some degradation. Molecular weight of cassava amylopectin was mostly preserved, whereas corn amylopectin was evenly attacked through the granule. Nevertheless, the B long branched chains of cassava amylopectin, with DP~37, were degraded whereas they were unchanged for corn amylopectin.Amido de mandioca modificado com ácido lático e radiação ultravioleta antes da secagem artificial têm mostrado boa capacidade de expansão, a exemplo da encontrada para o polvilho azedo. Neste trabalho, os efeitos do ácido lático e radiação UV sobre as características físico-químicas e estruturais de amidos de mandioca e milho foram investigados. Apenas o amido de mandioca modificado apresentou capacidade de expansão durante o forneamento. Do RVA, redução dos valores de viscosidade, boa estabilidade interna e nenhuma tendência a retrogradação para este amido modificado foi observado. O amido de milho não apresentou qualquer pico de viscosidade após modificação. Não foram observadas diferenças significativas nas propriedades térmicas, determinadas em DSC, entre os amidos nativos e modificados de ambas as fontes. As moléculas de amilopectina e amilose de ambos os amidos modificados mostraram alguma degradação. O peso molecular da amilopectina do amido de mandioca foi mais preservado, enquanto a amilopectina do amido de milho foi mais atacada em todo o grânulo. As

  14. Effect of the improved fermentation on physicochemical properties and sensorial acceptability of sour cassava starch

    Directory of Open Access Journals (Sweden)

    Maria Janete Angeloni Marcon

    2007-11-01

    Full Text Available The aim of this work was to study the effect of improved fermentation on sour cassava starch, aiming to reduce its fermentation time and to enhance its expansion capacity as well as its viscoamylographic properties and its sensorial acceptability. Results showed that the improved process of cassava starch production did not harm starch expansion, physicochemical properties or sensorial acceptability; it also produced starches with different viscoamylographic properties, which compared favourably to those of the sour cassava starch produced through current industrial methods.O Polvilho azedo é caracterizado pelas suas propriedades físicas, químicas e reológicas, as quais são diferentes do amido nativo do qual se originou. A propriedade de expansão é uma das mais importantes características do produto, sendo um parâmetro fundamental de avaliação do polvilho azedo. O resultado do perfil viscoamilográfico também é uma importante maneira de avaliação uma vez que cada amido tem um padrão viscoamilográfico definido de acordo com sua organização granular. Este trabalho determinou o efeito da fermentação melhorada pela adição de glicose, sobre o polvilho azedo, apontando para uma redução no tempo de fermentação e avaliando sua capacidade de expansão, suas propriedades viscoamilográficas e aceitabilidade sensorial. O processo de produção de polvilho azedo melhorado não prejudicou a expansão do amido, suas propriedades físico-químicas e sensoriais, mas sim resultou em amidos com diferentes propriedades viscoamilográficas melhores comparativamente ao polvilho azedo produzido pelo processo industrial atual.

  15. Effect of Gamma Irradiation on the Physicochemical and Functional Properties of Cassava Starch

    International Nuclear Information System (INIS)

    Cassava (Manihot esculanta Crantz) is popularly consumed as a staple food crop in many tropical countries in Africa, South America and Asia. In Africa the crop has been recognized as more than a subsistence crop. The crop is very important and commercially serves as a raw material for industries with significant effect on the economy of a country. Cassava roots contain high starch content and approximately half of the total roots produced is used for the production of starch for industrial purposes. Limitation to utilization of cassava roots by processors is due to its high perishability and bulkness, while native starches are structurally too weak and funtionally restricted for a wide variety of industrial applications. The objective of the project was to determine the effect of gamma irradiation as a modifying agent on native starch from three cassava varieties namely Ankra, Bosome nsia and TME419. Gamma radiation doses applied ranged between 0 - 20kGy and changes in physicochemical, functional and pasting indices of the starch were measured. Physicochemical indices measured were moisture content, amylose content, carbohydrate content, pH, ash content, fat content, protein content and L*a*b* values. Functional indices mesured were water absorption capacity, solubility index, bulk density, swelling power, fat absorption capacity, emulsion capacity, emulsion stability and least gelation concentration. Pasting indices measured were gelatinzation temperature, peak viscosity, viscosity at 92 degrees C and 50 degrees C, breakdown viscosity and setback viscosity. The pH, amylose content, carbohydrate content and ash content of native starch from Ankra, Bosome nsia and TME 419 were respectively 8.06, 7.80 and 7.18, 17.62%, 19.46% and 23.54%, 56.11%, 52.43% and 35.70%, 0.11%, 0.19% and 0.12%. The water absortion capacity and least gelation concentration of native starch from Ankra, Bosome nsia and TME 419 were 12.3%, 13.0% and 10.0%, respectively, least gelation

  16. Sugar-mediated semidian oscillation of gene expression in the cassava storage root regulates starch synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Christer; Baguma, Yona; Sun, Chuanxin; Boren, Mats; Olsson, Helena; Rosenqvist, Sara; Mutisya, Joel; Rubaihayo, Patrick R.; Jansson, Christer

    2008-01-15

    Starch branching enzyme (SBE) activity in the cassava storage root exhibited a diurnal fluctuation, dictated by a transcriptional oscillation of the corresponding SBE genes. The peak of SBE activity coincided with the onset of sucrose accumulation in the storage, and we conclude that the oscillatory mechanism keeps the starch synthetic apparatus in the storage root sink in tune with the flux of sucrose from the photosynthetic source. When storage roots were uncoupled from the source, SBE expression could be effectively induced by exogenous sucrose. Turanose, a sucrose isomer that cannot be metabolized by plants, mimicked the effect of sucrose, demonstrating that downstream metabolism of sucrose was not necessary for signal transmission. Also glucose and glucose-1-P induced SBE expression. Interestingly, induction by sucrose, turanose and glucose but not glucose-1-P sustained an overt semidian (12-h) oscillation in SBE expression and was sensitive to the hexokinase (HXK) inhibitor glucosamine. These results suggest a pivotal regulatory role for HXK during starch synthesis. Abscisic acid (ABA) was another potent inducer of SBE expression. Induction by ABA was similar to that of glucose-1-P in that it bypassed the semidian oscillator. Both the sugar and ABA signaling cascades were disrupted by okadaic acid, a protein phosphatase inhibitor. Based on these findings, we propose a model for sugar signaling in regulation of starch synthesis in the cassava storage root.

  17. Seasonal effects on the physico-chemical properties of starch from four cultivars of cassava

    Energy Technology Data Exchange (ETDEWEB)

    Asaoka, M.; Blanshard, J.M.V. (Nottingham Univ. (United Kingdom). Dept. of Applied Biochemistry and Food Science); Rickard, J.E. (Natural Resources Inst., Chatham (United Kingdom))

    1991-12-01

    Four varieties of cassava plants were cultivated at CIAT in Columbia and harvested on four different occasions with a view to evaluating whether there was any relationship between the texture of the cooked roots and the constituent starch. The organoleptic qualities of the cooked roots showed considerable differences in 'glassiness' and hardness of texture, both between varieties and times of harvest. The starch granules were isolated and examined by a variety of techniques. The size of the granules did vary with the seasons but there were only minor differences in the X-ary crystallinity, the elution patterns of iso-amylase-debranched material (including the amylose content), the proximate composition of the starch and the time course of digestion by glucoamylase. None of these provided a basis for explaining the differences in cooked texture. (orig.).

  18. Direct detection of toxigenic Bacillus cereus in dietary complement for children and cassava starch

    Directory of Open Access Journals (Sweden)

    Jnnifer A. Sánchez

    2015-09-01

    Full Text Available Bacillus cereus is a food contaminant anda known human pathogen that can causeemetic and diarrheal syndromes. In this studywe evaluated the presence of toxigenic B.cereus by multiplex PCR directly in dietarycomplement for children and cassava starchsamples collected on Medellin, Colombia.Of 75 dietary complement for childrensamples evaluated, 70.7% were contaminatedwith toxigenic B. cereus and four differenttoxigenic consortia were detected: I: nheA,hblC, cytK (9.8%, II: nheA, hblC (2%,III: hblC, cytK (41.2%, IV: hblC (47%.Of 75 cassava starch samples, 44% werecontaminated with toxigenic B. cereus andfour different toxigenic consortia weredetermined: I: nheA, hblC, cytK (48.5%,II: nheA, hblC, cytK, cesB (3%, III: hblC,cytK (30.3%, IV: hblC (18.2%. In general,in dietary complement for children onlyenterotoxigenic consortia were detectedwhile in cassava starch the enterotoxigenicconsortia predominated over the emetic.Multiplex PCR was useful to detect toxigenicB. cereus contamination allowing directand simultaneous detection of all toxingenes in foods. This study is the first inColombia to evaluate toxigenic B. cereus,providing information of importance formicrobiological risk evaluation in driedfoods.

  19. Enzymatically hydrolysed, acetylated and dually modified corn starch: physico-chemical, rheological and nutritional properties and effects on cake quality.

    Science.gov (United States)

    Sahnoun, Mouna; Ismail, Nouha; Kammoun, Radhouane

    2016-01-01

    Corn starch was treated by enzymatic hydrolysis with Aspergillus oryzae S2 α-amylase, acetylation with vinyl acetate, and dual modification. The dual modified starch displayed a higher substitution degree than the acetylated starch and lower reducing sugar content than the hydrolysed starch. The results revealed that the cooling viscosity and amylose content of those products decrease (P cake formulations at 5 and 10 % concentrations on a wheat flour basis and compared to native starch. The results revealed that when applied at 5 % concentrations, the modified starches reduced the hardness, cohesion, adhesion and chewiness of baked cakes and enhanced their elasticity, volume, height, crust color, and appearance as compared to native starch. These effects were more pronounced for the cake incorporating the dually modified starch.

  20. Saccharification of cassava starch by Saccharomycopsis fibuligera YCY1 isolated from Loog-Pang (rice cake starter

    Directory of Open Access Journals (Sweden)

    Aran H-Kittikun

    2008-04-01

    Full Text Available The main objectives of this study were to select amylolytic yeasts from Loog-Pang, a traditional starter culture for production of alcoholic foods and drinks in southern Thailand, and to optimize the saccharification of cassava starch to reducing sugar by the selected yeast isolate. Seventy-four yeast isolates were obtained from ten samples of Loog-Pang. The isolates were tested for amylolytic activity on Yeast-Peptone Cassava medium (YPC contained 30 g/l of cassava starch.Only three isolates showed amylolytic activity which produced clear zone on the YPC agar. The best amylolytic strain with clear zone of 8 mm was identified by 26s rDNA as Saccharomycopsis fibuligera. The optimum medium for saccharification by Saccharomycopsis fibuligera. YCY1 was only 50 g/l of cassava starch in distilled water without nitrogen sources added and pH adjustment. The optimal saccharification conditions were 200 ml cassava starch (50 g/l in 500 ml Erlenmeyer flask, shaking at 100 rpm and 37oC. Under these conditions, the highest reducing sugar was obtained 46±0.53 g/l after 120 h cultivation (84% of the theoretical yield.

  1. Summarization of Cassava Starch Deep Processing Products%木薯淀粉深加工产品概述

    Institute of Scientific and Technical Information of China (English)

    姚丹; 梁智

    2012-01-01

    木薯是广西的一大经济作物,是"三薯"作物之一。木薯的块茎是做淀粉的主要原料,木薯淀粉以其特有的特性,制淀粉和深加工制变性淀粉,具有优势,应用也十分广泛。除此之外,其它衍生物产品应用广泛,不断研究出新的产品。%Cassava is one important economic crop in Guangxi,one of three main tuber crops(cassava,potato and sweet potato) in the world.Tuber of cassava is key raw material for production of starch.Native starch and modified starch made from cassava possess great advantages and can be applied in a wide variety of fields.Moreover,derivatives of cassava starch can be used for many aims and new products keep emerging from continuous research.

  2. Molecular diversity of lactic acid bacteria from cassava sour starch (Colombia).

    Science.gov (United States)

    Omar, N B; Ampe, F; Raimbault, M; Guyot, J P; Tailliez, P

    2000-06-01

    Lactic acid bacteria and more particularly lactobacilli and Leuconostoc, are widely found in a wide variety of traditional fermented foods of tropical countries, made with cereals, tubers, meat or fish. These products represent a source of bacterial diversity that cannot be accurately analysed using classical phenotypic and biochemical tests. In the present work, the identification and the molecular diversity of lactic acid bacteria isolated from cassava sour starch fermentation were assessed by using a combination of complementary molecular methods: Randomly Amplified Polymorphic DNA fingerprinting (RAPD), plasmid profiling, hybridization using rRNA phylogenetic probes and partial 16S rDNA sequencing. The results revealed a large diversity of bacterial species (Lb. manihotivorans, Lb. plantarum, Lb. casei, Lb. hilgardii, Lb. buchneri, Lb. fermentum, Ln. mesenteroides and Pediococcus sp.). However, the most frequently isolated species were Lb. plantarum and Lb. manihotivorans. The RAPD analysis revealed a large molecular diversity between Lb. manihotivorans or Lb. plantarum strains. These results, observed on a rather limited number of samples, reveal that significant bacterial diversity is generated in traditional cassava sour starch fermentations. We propose that the presence of the amylolytic Lb. manihotivorans strains could have a role in sour starch processing. PMID:10930082

  3. Extracellular amylase(s) production by fungi Botryodiplodia theobromae and Rhizopus oryzae grown on cassava starch residue.

    Science.gov (United States)

    Ray, R C

    2004-10-01

    The fungi Botryodiplodia theobromae and Rhizopus oryzae produce extracellular amylase when grown on a liquid medium containing 2% (WN) soluble starch or cassava starch residue(CSR) (as starch equivalent), a waste generated after extraction of starch from cassava, as the sole carbon source. Using CSR as the sole carbon source, the highest amylase activity of 3.25 and 3.8 units (mg, glucose released x ml(-1) x h(-1)) were obtained in shake flask cultures during the late stationary phase of growth of B. theobromae and R. oryzae, respectively. These values were slightly lower than the values obtained using soluble starch as the carbon source. Maximum enzyme synthesis in CSR incorporated medium occurred at the growth temperature of 30 degrees C and pH 6.0. Presence of inorganic NH4+ salts like ammonium acetate and ammonium nitrate in culture medium yielded more amylase than the other nitrogen sources. Amylase(s) production in the controlled environment of a Table-Top glass Jar Fermenter (2-L capacity) was 4.8 and 5.1 units for B. theobromae and R. oryzae, respectively using CSR as the carbon substrate. It is concluded that CSR, a cheap agricultural waste obtained after starch extraction from cassava could replace soluble starch as carbon substrate for commercial production of fungal amylase(s).

  4. Thermoanalytical and starch content evaluation of cassava bagasse as agro-industrial residue

    Directory of Open Access Journals (Sweden)

    Luiz Gustavo Lacerda

    2009-11-01

    Full Text Available Starch nutritional fractions as well as thermal properties and other analysis are essential for food and industrial application. Cassava bagasse is an important agro-industrial residue and its starch content was evaluated using two alternative methods. Thermal characterization and microscopy analyses helped to understand how hydrolysis digests starchy fraction of cassava bagasse. The melting point of cassava starch occurred at 169.2ºC. Regarding TG analyses, after moisture content, there were observed two main mass losses for all samples. Results suggest hydrolysis carried out using enzyme is less effective in order to convert total starch content in cassava bagasse. However, using sulfuric acid, fibers are affected by analyses conditions.As frações nutricionais bem como as propriedades térmicas e outras análises são essenciais para a indústria de alimentos e suas aplicações O bagaço de mandioca é um importante resíduo agroindustrial e seu teor de amido foi avaliado por dois métodos alternativos. A caracterização por análise térmica e microscopia ajudou na compreensão de como a hidrólise digere a fração amilácea do bagaço de mandioca, O ponto de fusão foi de 170ºC, a análise termogravimétrica (TG mostrou após a perda de umidade do material, duas principais perdas de massa em todas as amostras analisadas. Os resultados sugerem que a hidrólise enzimática é menos eficiente na conversão total de amido no bagaço de mandioca. No entanto, o uso de ácido sulfúrico degradou até mesmo a parcela fibrosa do material, afetando as condições de análise.

  5. Effect of Soil Burial on Tensile Properties of Polypropylene/Plasticized Cassava Starch Blends

    Directory of Open Access Journals (Sweden)

    Henry C. Obasi

    2013-01-01

    Full Text Available Polypropylene (PP/plasticized cassava starch (PCS blended with and without compatibilizer (polypropylene-graft-maleic anhydride (PP-g-MA via melt blending were prepared for soil burial which lasted for 90 days. Plasticized starch loadings of 0, 10, 20, 30, 40, and 50 wt.% were used, while pp-g-ma was used at 10 wt.% based on starch weight. The PP/PCS and PP/PCS/PP-G-MA blends were evaluated for their tensile properties. It was observed that the tensile strength, elongation at break, and young’s modulus decreased with increases in soil burial time as well as starch content for PP/PCS blends. Similar treads for the tensile properties were observed for PP/PCS/PP-g-MA, but with higher properties as compared to uncompatibilized blends. However, the tensile properties for both PP/PCS and PP/PCS/PP-g-Ma decrease with increases in starch loading and also as the burial period progressed.

  6. AMMI Model for Interpreting Clone-Environment Interaction in Starch Yield of Cassava

    Directory of Open Access Journals (Sweden)

    SHOLIHIN

    2011-03-01

    Full Text Available The aim of the study was to analyze the interaction between clone and environment for starch yield in six month-old plants of cassava clones based on additive main effects and multiplicative interaction (AMMI model. The experiments were conducted on mineral soil in four different locations: Lumajang (inceptisol, Kediri (entisol, Pati (alfisol, and Tulangbawang (ultisol. The experiments were carried out during 2004-2005, using a split plot design withthree replications. The main plots were the simple and the improved technology. The clones used were fifteen clones. Parameter recorded was starch yield (kg/ha of the 6 month old plants. The data were analyzed using the AMMI model. Based on the AMMI analysis, environmental factors being important in determining the stability of the starch yield were soil density for subsoil, pH of topsoil, and the maximum air humidity four months after planting. The clones of CMM97001-87, CMM97002-183, CMM97011-191, CMM97006-44, and Adhira 4 were identified as stable clones in starch yield within 6 month-old plants. CMM97007-235 was adapted to maximum relative humidity 4 months after planting and to lower pH of topsoil, whereas, MLG 10311 was adapted to lower bulk density. The mean starch yield of MLG 10311 was the highest six months after planting.

  7. Studying a new technique and implementing a pilot-line process for obtaining dextrins from cassava starch

    Directory of Open Access Journals (Sweden)

    Johanna Aristizábal Galvis

    2010-04-01

    Full Text Available This study proposes and develops a new technique for dry-route dextrin production consisting of converting cassava starch pellets on a fixed-bed dryer; this technique is more applicable to rural Colombian agro-business in technical, economic, social and environmental terms, particularly to so-called “rallanderías” compared to currently available dextrin production technology. The proposed process is practically clean, requires low investment, allows humid starch-cake to be directly used without the need for expensive pre-drying equipment, eliminates large quantities of dust being produced thereby leading to an easily-handled and packaged product being obtained. Different dex-trinisation technologies were compared; a pilot-line was implemented which included blending, granulation and drying units. The variables evaluated were cassava-starch variety, catalyst concentration and agglutinant type and concentration; pellet-size, bed-thickness and air-speed were also evaluated during blending, granulation and drying stages, respectively. It was determined that using 0.1-0.3% HCl on cassava starch, 1.5-3% cassava starch paste, L/D=1.25 pellets, a 55ºC pre -drying phase and 150ºC final conversion on 2 cm thickness fixed-bed dryer at 2-3 m/s air speed led to obtaining low friability (13%, high rupture force (1.3 kg-f, high solubility (90-100% and low fluidity (50-70 s dextrin pellets. An adhesive was then obtained from the dextrin resulting from the process described above for sealing cardboard-boxes and cartons having greater stickiness, tensile strength and stability compared to corn dextrin adhesive, suggesting that the proposed new cassava dextrin production technique constitutes a good technological option for adding value to Colombian cassava production at small “rallandería” level.

  8. Thermal characterization and detailed kinetic analysis of Cassava starch thermo-oxidative degradation.

    Science.gov (United States)

    Janković, Bojan

    2013-06-20

    Detailed kinetic analysis of Cassava starch thermo-oxidative degradation was performed, using thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) at four different heating rates. It was found that degradation process is very complex, as identified through continuous change of apparent activation energy with degree of degradation. It was established that process proceeds through three main degradation stages with one additional sub-stage attached to the second degradation stage, which was detected by appearance of "shoulder" on DTG curves. It was found that most important degradation stage can be described by "lumped" model, which implies that free radicals simultaneously attack both linear and branched molecular forms of the starch. This is characterized by an unusually high value of obtained reaction order (n=3.49). Application of nonlinear least squares method was confirmed the reliability of evaluated kinetic parameters and function of reaction mechanism, which were derived on the basis of other kinetic methods.

  9. Robust and biodegradable polymer of cassava starch and modified natural rubber.

    Science.gov (United States)

    Riyajan, Sa-Ad

    2015-12-10

    The application of starch based materials for packaging purposes has attracted significant interest because they are both cheap and renewable resources. The study investigated the preparation and properties of a novel biopolymer sheet produced from a blend of maleated epoxidized natural rubber (MENR) and natural rubber-g-cassava starch (NR-g-CSt). The water resistance, toluene resistance and elongation at break of the polymer blend were enhanced after the addition of the MENR compared to pristine NR-g-CSt. The maximum tensile strength and thermal stability of the NR-g-CSt/MENR blend were found in the 100:50 NR-g-CSt:MENR blend. The novel films demonstrated good biodegradability in soil.

  10. Characterization of cassava starch based foam blended with plant proteins, kraft fiber, and palm oil.

    Science.gov (United States)

    Kaisangsri, Nattapon; Kerdchoechuen, Orapin; Laohakunjit, Natta

    2014-09-22

    Cassava starch foam (CSF) trays blended with zein, gluten, soy protein, kraft fiber, and palm oil at various concentrations: 0, 5, 10 and 15% by weight of starch, were characterized. The addition of zein and gluten into CSF resulted in consolidated and homogeneous structural foams compared to its controls. Moreover, the flexural and compressive strength increased with increasing kraft, zein and gluten. CSF containing 15% kraft gave the highest flexural and compressive strength. However, the addition of palm oil into CSF gave the lowest flexural strength and compressive strength. The observed water absorption and water solubility index of CSFs blended with 15% zein and 15% gluten protein was lowest. Although kraft, zein and gluten could improve mechanical properties, water absorption and water solubility were greater than the expanded polystyrene foam (EPS). The CSF trays in this study might be an alternative for packing low water content foods.

  11. Experimental study on drying kinetic of cassava starch in a pneumatic drying system

    Science.gov (United States)

    Suherman, Kumoro, Andri Cahyo; Kusworo, Tutuk Djoko

    2015-12-01

    The aims of this study are to present the experimental research on the drying of cassava starch in a pneumatic dryer, to describe its drying curves, as well as to calculate its thermal efficiency. The effects of operating conditions, namely the inlet air temperature (60-100 °C) and solid-gas flow rate ratio (Ms/Mg 0.1-0.3) were studied. Heat transfer is accomplished through convection mechanism in a drying chamber based on the principle of direct contact between the heated air and the moist material. During the drying process, intensive heat and mass transfer between the drying air and the cassava starch take place. In order to meet the SNI standards on solid water content, the drying process was done in two cycles. The higher the temperature of the drying air, the lower the water content of the solids exiting the dryer. Thermal efficiency of the 2nd cycle was found to be lower than the 1st cycle.

  12. Preparation of metal adsorbent from poly(methyl acrylate)-grafted-cassava starch via gamma irradiation

    International Nuclear Information System (INIS)

    Metal adsorbent containing hydroxamic acid groups was successfully synthesized by radiation-induced graft copolymerization of methyl acrylate (MA) onto cassava starch. The optimum conditions for grafting were studied in terms of % degree of grafting (Dg). Conversion of the ester groups present in poly(methyl acrylate)-grafted-cassava starch copolymer into hydroxamic acid was carried out by treatment with hydroxylamine (HA) in the presence of alkaline solution. The maximum percentage conversion of the ester groups of the grafted copolymer, % Dg=191 (7.63 mmol/g of MA), into the hydroxamic groups was 70% (5.35 mmol/g of MA) at the optimum condition. The adsorbent of 191%Dg had total adsorption capacities of 2.6, 1.46, 1.36, 1.15 and 1.6 mmol/g-adsorbent for Cd2+, Al3+, UO22+, V5+ and Pb2+, respectively, in the batch mode adsorption. - Highlights: ► Adsorbent containing hydroxamic acid group was prepared by radiation-induced grafting. ► The adsorbent exhibited a remarkable % adsorption for Cd2+, Al3+, UO22+, V5+ and Pb2+. ► The selectivity of adsorbent towards metal ions used is in this order: Cd2+>Pb2+> Al3+> UO22+ > V5+.

  13. Changes in physical properties of extruded sour cassava starch and quinoa flour blend snacks

    Directory of Open Access Journals (Sweden)

    Lívia Giolo Taverna

    2012-12-01

    Full Text Available Given the broad acceptance of sour cassava starch biscuits in Brazil and the nutritional quality of quinoa flour, this study aimed to evaluate the effect of extrusion temperature, screw speed, moisture, and amount of quinoa flour on the physical properties of puffed snacks. Extrusion process was carried out using a single-screw extruder in a factorial central composite design with four factors. Effects of moisture and amount of quinoa flour on the expansion index and specific volume of snacks were observed. There was a pronounced increase in water solubility index of blends with the extrusion process with significant effects of all process parameters on the WSI. Higher water absorption index (WAI was observed under high temperature, low moisture, and lower quinoa flour amount. Temperature and amount of quinoa flour influenced the color of the snacks. A positive quadratic effect of quinoa flour on hardness of products was observed. Blends of sour cassava starch and quinoa flour have good potential for use as raw material in production of extruded snacks with good physical properties.

  14. Carboxymethylation of Cassava Starch in Different Solvents and Solvent-Water Mixtures: Optimization of Reaction Conditions

    Science.gov (United States)

    Nwokocha, Louis M.; Ogunmola, Gabiel B.

    The influence of reaction medium on carboxymethylation process was investigated by treating cassava starch with sodium monochloroacetate in different solvents and solvent-water mixtures under alkaline conditions. The amount of carboxyl groups introduced into the starch moiety was determined titrimetrically and used to calculate the Degree of Substitution (DS) and Reaction Efficiency (RE). The results showed that carboxymethylation is significantly affected by the nature of reaction medium at p<0.05. Carboxymethylation in different solvent-water mixtures showed that aqueous 80% n-propanol offered the best medium for carboxymethylation. Optimization of reaction conditions in aqueous 80% n-propanol showed that the best condition for carboxymethylation was at starch-liquor ratio of 1:3, NaOH/reagent molar ratio of 4.0 and reagent-starch molar ratio of 0.35. An increase in temperature was required to effect the reaction at shorter time. At 55°C the highest values of DS and RE achieved in 0.5 h would require three hours to achieve the same values of DS and RE at 45°C.

  15. Promoter regulatory domain identification of cassava starch synthase IIb gene in transgenic tobacco.

    Science.gov (United States)

    Guan, Zhihui; Chen, Xin; Xie, Hairong; Wang, Wenquan

    2016-05-01

    Soluble starch synthase is a key enzyme in the starch biosynthesis pathway, and its enzyme activity significantly influences starch components in cassava storage root. However, studies on the regulation mechanism of soluble starch synthase gene are rare. In this study, we cloned the 5' flanking sequence of the MeSSIIb gene and predicted the distribution of cis-elements. The region from -453 to -1 was considered the primary core promoter by the quantitative detection of GUS activity in transgenic tobacco plants containing 5' truncated promoters fused with the GUS gene. Analysis results clarified that the region from -531 to -454 significantly repressed promoter activity. The region from -453 to -388 was a repressive domain of ethylene, and some unknown drought responsive cis-elements were located in the region from -387 to -1. These findings will provide useful information on the functional assay and transcriptional regulation mechanisms of the MeSSIIb gene. PMID:26919397

  16. Growth performance and carcass characteristics of feedlot Thai native × Lowline Angus crossbred steer fed with fermented cassava starch residue.

    Science.gov (United States)

    Pilajun, Ruangyote; Wanapat, Metha

    2016-04-01

    Ten Thai native × Lowline Angus crossbred (50:50) steers were used in a completely randomized design to receive two treatments including concentrate containing cassava chips (Control) and fermented cassava starch residue (FCSR) as major carbohydrate sources. FCSR was prepared as yeast (Saccharomyces cerevisiae) inoculates with exogenous enzyme addition. All steers received ad libitum rice straw and concentrate in equal proportions (1:1). Replacement of cassava chip with FCSR increased neutral detergent fiber and acid detergent fiber intakes but decreased non-protein nitrogen intake of steers. Digestibility of dry matter, organic matter, and crude protein were decreased with replacement of cassava chip by FCSR; however, digested nutrients were similar between groups. Replacement of cassava chip in the concentrate with FCSR resulted in comparable growth performance and feed efficiency of the feedlot steers. Moreover, carcass characteristics in terms of yield and meat quality of the steers were not affected by cassava chips replaced by FCSR as a major carbohydrate source in the concentrate. In conclusion, replacement of cassava chip in the concentrate with FCSR decreased feed digestibility; however, it did not impact negatively on growth performance and carcass traits of feedlot Thai native × Lowline Angus crossbred steers. PMID:26942915

  17. High yields of fatty acid and neutral lipid production from cassava bagasse hydrolysate (CBH) by heterotrophic Chlorella protothecoides.

    Science.gov (United States)

    Chen, Junhui; Liu, Xiaoguang; Wei, Dong; Chen, Gu

    2015-09-01

    The fermentation process for high yields of fatty acid and neutral lipid production from cassava bagasse hydrolysate (CBH) was developed by heterotrophic Chlorella protothecoides. An efficient single-step enzymatic hydrolysis of cassava bagasse (CB) by cellulase was firstly developed to produce >30 g/L of reducing sugars. The concentrated CBH was subsequently applied in a batch culture, producing 7.9 g/L of dry biomass with yield of 0.44 g/g reducing sugar and 34.3 wt% of fatty acids and 48.6 wt% of neutral lipids. Furthermore, fed-batch fermentation using CBH achieved higher yields of fatty acids (41.0 wt% and a titer of 5.83 g/L) and neutral lipids (58.4 wt% and yield of 0.22 g/g reducing sugar). Additionally, the fatty acid profile analysis showed that the intercellular lipid was suitable to prepare high-quality biodiesel. This study demonstrated the feasibility of using CBH as low-cost feedstock to produce crude algal oil for sustainable biodiesel production.

  18. Starch and starch hydrolysates are favorable carbon sources for Bifidobacteria in the human gut

    OpenAIRE

    Liu, Songling; Ren, Fazheng; Zhao, Liang; Jiang, Lu; Hao, Yanling; Jin, Junhua; Zhang, Ming; Guo, Huiyuan; Lei, Xingen; Sun, Erna; Liu, Hongna

    2015-01-01

    Background Bifidobacteria are key commensals in human gut, and their abundance is associated with the health of their hosts. Although they are dominant in infant gut, their number becomes lower in adult gut. The changes of the diet are considered to be main reason for this difference. Large amounts of whole-genomic sequence data of bifidobacteria make it possible to elucidate the genetic interpretation of their adaptation to the nutrient environment. Among the nutrients in human gut, starch i...

  19. Energy and exergy analyses of native cassava starch drying in a tray dryer

    International Nuclear Information System (INIS)

    Energy and exergy analyses of native cassava starch drying in a tray dryer were carried out to assess the performance of the system in terms of energy utilization, energy utilization ratio, energy efficiency, exergy inflow and outflow, exergy loss and exegetic efficiency. The results indicated that for the starch with ash content of 0.76%, 0.85% crude protein, 0.16% crude fat, negligible amount of fiber, average granule size of 14.1 μm, pH of 5.88, amylose content of 23.45% and degree of crystallinity of 22.34%, energy utilization and energy utilization ratio increased from 1.93 to 5.51 J/s and 0.65 to 0.6 as the drying temperature increased from 40 to 60 °C. Energy efficiency increased from 16.036 to 30.645%, while exergy inflow, outflow and losses increased from 0.399 to 2.686, 0.055 to 0.555 and 0.344 to 2.131 J/s respectively in the above temperature range. Exergetic efficiency increased with increase in both drying air temperature and energy utilization and was lower than energy efficiency. Exergetic improvement potential also increased with increase in drying air temperature. Model equations that could be used to express the energy and exergy parameters as a function of drying temperature were established. - Highlights: • Energy and exergy analyses of cassava starch drying in a tray dryer were carried out. • Energy utilization increased with drying temperature. • Energy efficiency was higher than exergy efficiency. • Energy and exergy efficiencies increased with increase in temperature. • Improvement potential increased with increase in temperature

  20. In vitro amylolysis of pulse and hylon VII starches explained in terms of their composition, morphology, granule architecture and interaction between hydrolysed starch chains.

    Science.gov (United States)

    Maaran, S; Hoover, R; Vamadevan, V; Waduge, R N; Liu, Q

    2016-02-01

    The objective of this study was to understand the factors underlying the susceptibility of pulse (lablab bean, navy bean, rice bean, tepary bean, velvet bean, and wrinkled pea) and hylon VII starches towards in vitro hydrolysis by the combined action of pancreatin and amyloglucosidase. The time taken to reach an equivalent level of hydrolysis (50%) varied significantly among the starches. Changes to molecular order, crystallinity, double helical content, radial orientation of starch chains (polarized light), enthalpy and apparent amylose content during the progress of hydrolysis showed that rate and extent of hydrolysis were influenced both by the structure of the native starches at different levels (molecular, mesoscopic, microscopic) of granule organization, and by the extent of retrogradation between hydrolysed starch chains.

  1. Super water absorbent by radiation graft polymerization of acrylic monomers onto cassava starch

    International Nuclear Information System (INIS)

    Water superabsorbent gel has been applying in personal care, agriculture, medical supplies and water purification. In agricultural application, the gel will help to control soil erosion, limit loss of nutrients and slit for plants, decrease irrigation frequency, improve infiltration, and increase water retention in prolonged arid soil and droughts. The gel absorbs many times its weight in available water. The gel from poly(acrylamide) was developed in the 60's to grow plants in the deserts. The other gel from poly(acrylic acid) was used to absorb rapidly in baby diapers, sanitary napkins. These polymers are commonly produced from natural gas, which have recently been introduced as a soil conditioner with great success. Prior to these polymers, peat moss, agro-waste (sugar-cane waste, coffee-shell, etc.), activated kaolin were the alternative soil additives to hold water (20 times its weight), but poly(acrylamide) absorbs 400 times its weight and polyacrylate is capable of absorbing greater amounts of liquid than poly(acrylamide). In addition, starch and cellulose are biodegradable naturally occurring polymers, which are not capable of holding a great amount of water, but their modification by graft polymerization or crosslinking through radiation or chemical initiation techniques, they become the potential superabsorbent polymers. Radiation initiation of chemical reactions has been widely known for making novel materials because the degree of polymerization, grafting and crosslinking process can easily be controlled. Recently, it was shown that the starch and cellulose derivatives such as carboxymethyl starch, carboxymethyl starch can be synthesized by radiation-induced crosslinking at high concentrations. Their utilization in agriculture seems to be appropriately evaluated. In this article, the graft polymerization and crosslinking of acrylic acid onto cassava starch and field trial of its product (GAM-Sorb S) are reported. (author)

  2. Peak root and starch weights of ten early bulking cultivators of cassava (Manihot esculenta crantz) in Ghana

    International Nuclear Information System (INIS)

    Peak yields of total fresh root weight (TFRW), total dry root weight (TDRW) and total starch weight (TSW) of ten cassava (Manihot esculenta crantz) cultivatar are reported. Planting of the cassava cultivatars was carried out in a randomized complete block design with three replications. The cassava roots were harvested first at 5 months after planting (MAP) and every month thereafter. Thr percentage starch content was determined using a UV-spectrophotometer at 690nm wavelength. Four ain periods after planting could be identified for early bulking cultivatars: (7 MAP - cultivatars 115, DMA )30, HO 001 and UCC 096; 9 MAP - cultivatars 126 and HO 015; 11 MAP - cultivatars 90 and MQA98/11; 12 MAP - cultivatars CR001/102 and HO 008). Time to achieve peak yield differed in some cultivatars but was the same for TFRW, TDRW and TSW. Cassava cultivatar HO 008 had the highest peak of TDRW and TSW in roots while cultivatar MQA98/11 had the lowest. On dry weight basis, starch content was higher than 72%. Yield loss estimates due to delayed harvest of the cultiatars are presented. (au)

  3. Biodegradability and plasticizing effect of yerba mate extract on cassava starch edible films.

    Science.gov (United States)

    Medina Jaramillo, Carolina; Gutiérrez, Tomy J; Goyanes, Silvia; Bernal, Celina; Famá, Lucía

    2016-10-20

    Biodegradable and edible cassava starch-glycerol based films with different concentrations of yerba mate extract (0, 5 and 20wt.%) were prepared by casting. The plasticizing effect of yerba mate extract when it was incorporated into the matrix as an antioxidant was investigated. Thermal degradation and biodegradability of the obtained biofilms were also studied. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FTIR), X-ray diffraction analysis (XRD), water absorbance, stability in different solutions and biodegradability studies were performed. The clear correlation among the results obtained from the different analysis confirmed the plasticizing effect of yerba mate extract on the starch-glycerol matrix. Also, the extract led to a decrease in the degradation time of the films in soil ensuring their complete biodegradability before two weeks and to films stability in acidic and alkaline media. The plasticizing effect of yerba mate extract makes it an attractive additive for starch films which will be used as packaging or coating; and its contribution to an earlier biodegradability will contribute to waste reduction. PMID:27474554

  4. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization.

    Science.gov (United States)

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-01

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement. PMID:26791570

  5. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization.

    Science.gov (United States)

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-01

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement.

  6. Obtaining a Flexible Film Elaborated from Cassava Thermoplastic Starch and Polylactic Acid

    Directory of Open Access Journals (Sweden)

    Germán A. Arboleda

    2015-01-01

    Full Text Available A flexible film was obtained from a blend of cassava thermoplastic starch and polylactic acid, using maleic anhydride as coupling agent. For this, an experimental design with three factors was used: polylactic acid content, coupling agent content, and temperature profile of the blown extrusion. It was found that the three factors generated significant differences on the response variables of tensile mechanical properties individually as in their triple interaction. Differential scanning calorimetry (DSC was used by understanding the behavior of thermal properties of TPS/PLA blends with and without coupling agent, finding similar results between both. From this, the combination with 28% polylactic acid, 0.87% coupling agent, and 155.75°C temperature profile permitted the obtaining of a material with outstanding mechanical properties and offered advantages from the economic point of view.

  7. Superabsorbent Prepared by Radiation Induced Graft Copolymerization of Acrylic Acid onto Cassava Starch. Chapter 18

    International Nuclear Information System (INIS)

    Superabsorbent was synthesized by radiation induced graft polymerization of acrylic acid onto cassava starch. Parameters such as the absorbed dose and the amount of monomer were investigated in order to determine the optimum conditions for the grafting polymerization. Water retention, germination percentage, and germination energy were also determined in order to evaluate the possibility of superabsorbent in agricultural applications, especially in arid regions. The graft copolymer was characterized by the Fourier transform infrared spectroscopy (FTIR). Results indicated that the sand mixed with 0.1% wt superabsorbent could absorb more water than the sand without superabsorbent. The germination energy of corn seeds mixed with 0.5% superabsorbent was obviously higher than those without superabsorbent. These experimental results showed that the superabsorbent has considerable effects on seed germination and the growth of young plants. (author)

  8. Effect of fermentation conditions on biohydrogen production from cassava starch by anaerobic mixed cultures

    Science.gov (United States)

    Tien, Hai M.; Le, Kien A.; Tran, An T.; Le, Phung K.

    2016-06-01

    In this work, a series of batch tests were conducted to investigate the effect of pH, temperature, fermentation time, and inoculums ratio to hydrogen production using cassava starch as a substrate. The statistical analysis of the experiment indicated that the significant effects for the fermentation yield were the main effect of temperature, pH and inoculums ratio. It was fouund that the suitable fermentation conditions of biohydrogen production should be at temperature 40 ° C; pH 6.5, inoculums to medium ratio 10 % and COD operation at 4800 g/mL. The maximum value of hydrogen volume produced was 76.22 mL. These affected has been evaluated and the result can be used as an reference for the pilot or industrial biohydrogen production.

  9. Quantitative trait loci and candidate genes associated with starch pasting viscosity characteristics in cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Thanyasiriwat, T; Sraphet, S; Whankaew, S; Boonseng, O; Bao, J; Lightfoot, D A; Tangphatsornruang, S; Triwitayakorn, K

    2014-01-01

    Starch pasting viscosity is an important quality trait in cassava (Manihot esculenta Crantz) cultivars. The aim here was to identify loci and candidate genes associated with the starch pasting viscosity. Quantitative trait loci (QTL) mapping for seven pasting viscosity parameters was carried out using 100 lines of an F1 mapping population from a cross between two cassava cultivars Huay Bong 60 and Hanatee. Starch samples were obtained from roots of cassava grown in 2008 and 2009 at Rayong, and in 2009 at Lop Buri province, Thailand. The traits showed continuous distribution among the F1 progeny with transgressive variation. Fifteen QTL were identified from mean trait data, with Logarithm of Odds (LOD) values from 2.77-13.01 and phenotype variations explained (PVE) from10.0-48.4%. In addition, 48 QTL were identified in separate environments. The LOD values ranged from 2.55-8.68 and explained 6.6-43.7% of phenotype variation. The loci were located on 19 linkage groups. The most important QTL for pasting temperature (PT) (qPT.1LG1) from mean trait values showed largest effect with highest LOD value (13.01) and PVE (48.4%). The QTL co-localised with PT and pasting time (PTi) loci that were identified in separate environments. Candidate genes were identified within the QTL peak regions. However, the major genes of interest, encoding the family of glycosyl or glucosyl transferases and hydrolases, were located at the periphery of QTL peaks. The loci identified could be effectively applied in breeding programmes to improve cassava starch quality. Alleles of candidate genes should be further studied in order to better understand their effects on starch quality traits.

  10. Production of Starch Based Bioplastic from Cassava Peel Reinforced with Microcrystalline Celllulose Avicel PH101 Using Sorbitol as Plasticizer

    Science.gov (United States)

    Maulida; Siagian, M.; Tarigan, P.

    2016-04-01

    The production of starch based bioplastics from cassava peel reeinforced with microcrystalline cellulose using sorbitol as plasticizer were investigated. Physical properties of bioplastics were determined by density, water uptake, tensile strength and Fourier Transform Infrared Spectroscopy. Bioplastics were prepared from cassava peel starch plasticized using sorbitol with variation of 20; 25; 30% (wt/v of sorbitol to starch) reinforced with microcrystalline celllulose (MCC) Avicel PH101 fillers with range of 0 to 6% (wt/wt of MCC to starch). The results showed improvement in tensile strength with higher MCC content up to 9, 12 mpa compared to non-reinforced bioplastics. This could be mainly attributed to the strong hydrogen bonds between MCC and starch. On the contrary, the addition of MCC decreased the elongation at break, density and water uptake. Fourier Transform Infrared Spectroscopy showed the functional groups of bioplastics, which the majority of O-H groups were found at the bioplastics with reinforcing filler MCC that represented substantial hydrogen bonds. The highest tensile strength value was obtained for bioplastic with MCC content 6% and sorbitol content 20%. With good adhesion between MCC and starch the production of bioplastics could be widely used as a substitute for conventional plastics with more benefits to the environment.

  11. Silage of residue from the extraction of cassava starch in diets from lactating holstein cows

    Directory of Open Access Journals (Sweden)

    Maximiliane Alavarse Zambom

    2015-06-01

    Full Text Available The objective of evaluating the intake and digestibility of nutrients, milk production, production efficiency and composition, and blood parameters of Holstein cows fed silage of the residue from the extraction of cassava starch (SRECS, replacing 0%, 25%, 50%, 75%, or 100% of the corn feed. Cows with average production of 35 kg of milk a day were assigned in a 5x5 Latin square design, and for the 21 days trial period, they were housed in stalls and fed individually to control the dietary food, stool samples were performed to estimate the digestibility of nutrients. Milking were held twice a day, measuring the production and analysis of milk composition in each experimental period. Blood collections were performed at the end of each period to evaluate the metabolic condition of the cows. The data were analyzed using variance analysis and polynomial regression. The replacement of corn by SRECS did not affect the intake of dry matter (DM or total carbohydrates (TC. There was a linear decrease in the intake of ether extract (EE, and a linear increase in the intake of neutral (NDF and acid detergent fiber (ADF, indicating a quadratic regression with the intake of crude protein (CP. The use SRECS presented growing effect digestibility of the ADF, showing a positive linear effect. The total digestible nutrients (TDN did not differ between the diets and had an average of 66.03%. There was a trend of reduction (10% in the production, with consequent increase in delight in the concentration of its components. There was no change in the measured metabolites. The use of silage of the residue from the extraction of cassava starch to replace the ground corn on feed, negatively affects the nutrient intake without changing the efficiency of milk production, milk composition, in the same way as blood parameters of lactating cows.

  12. Metal Adsorbent Prepared from Poly(Methyl Acrylate)-Grafted Cassava Starch via Gamma Irradiation

    International Nuclear Information System (INIS)

    Metal adsorbent containing hydroxamic acid groups was successfully synthesized by radiation-induced graft copolymerization of methyl acrylate (MA) onto cassava starch. The optimum conditions for grafting were studied in terms of % degree of grafting (Dg). Conversion of the ester groups present in poly(methyl acrylate)-grafted-cassava starch copolymer into hydroxamic acid was carried out by treatment with hydroxylamine (HA) in the presence of alkaline solution. The maximum percentage conversion of the ester groups of the grafted copolymer, %Dg = 191 (7.63 mmol/g of MA), into the hydroxamic groups was 70% (5.35 mmol/g of MA) at the optimum conditions: in a mixture solution of 20% HA (w/v) and methanol solution (methanol:H2O = 5:1) 300 mL, pH 13, reaction time 2 h, and 20 g of grafted copolymer. The adsorbent was characterized by FTIR, TGA, and DSC. The presence of electron donating groups in adsorbent containing hydroxamic acid groups gives the ability to form polycomplexes with metal ions. The ability of the adsorbent to adsorb various metals was investigated in order to evaluate the possibility of its use in metal adsorption. The adsorbent exhibited a remarkable % adsorption for Cd2+, Al3+, UO22+, V5+ and Pb2+ at pH 3, 4, 5, 4, and 3, respectively. The adsorbent of 191%Dg had total adsorption capacities of 2.6, 1.46, 1.36, 1.15, and 1.6 mmol/g adsorbent for Cd2+, Al3+, UO22+, V5+ and Pb2+, respectively, in the batch mode adsorption. (author)

  13. Bio-composites of cassava starch-green coconut fiber: part II-Structure and properties.

    Science.gov (United States)

    Lomelí-Ramírez, María Guadalupe; Kestur, Satyanarayana G; Manríquez-González, Ricardo; Iwakiri, Setsuo; de Muniz, Graciela Bolzon; Flores-Sahagun, Thais Sydenstricker

    2014-02-15

    Development of any new material requires its complete characterization to find potential applications. In that direction, preparation of bio-composites of cassava starch containing up to 30 wt.% green coconut fibers from Brazil by thermal molding process was reported earlier. Their characterization regarding physical and tensile properties of both untreated and treated matrices and their composites were also reported. Structural studies through FTIR and XRD and thermal stability of the above mentioned composites are presented in this paper. FT-IR studies revealed decomposition of components in the matrix; the starch was neither chemically affected nor modified by either glycerol or the amount of fiber. XRD studies indicated increasing crystallinity of the composites with increasing amount of fiber content. Thermal studies through TGA/DTA showed improvement of thermal stability with increasing amount of fiber incorporation, while DMTA showed increasing storage modulus, higher glass transition temperature and lower damping with increasing fiber content. Improved interfacial bonding between the matrix and fibers could be the cause for the above results. PMID:24507321

  14. A Study of Specific Heat Capacity Functions of Polyvinyl Alcohol- Cassava Starch Blends

    Science.gov (United States)

    Sin, Lee Tin; Rahman, W. A. W. A.; Rahmat, A. R.; Morad, N. A.; Salleh, M. S. N.

    2010-03-01

    The specific heat capacity ( C sp) of polyvinyl alcohol (PVOH) blends with cassava starch (CSS) was studied by the differential scanning calorimetry method. Specimens of PVOH-CSS blends: PPV37 (70 mass% CSS) and PPV46 (60 mass% CSS) were prepared by a melt blending method with glycerol added as a plasticizer. The results showed that the specific heat capacity of PPV37 and PPV46 at temperatures from 330 K to 530 K increased from (2.963 to 14.995) J· g-1 · K-1 and (2.517 to 14.727) J · g-1· K-1, respectively. The specific heat capacity of PVOH-CSS depends on the amount of starch. The specific heat capacity of the specimens can be approximated by polynomial equations with a curve fitting regression > 0.992. For instance, the specific heat capacity (in J · g-1 · K-1) of PPV37 can be expressed by C sp = -17.824 + 0.063 T and PPV46 by C sp = -18.047 + 0.061 T, where T is the temperature (in K).

  15. Water desorption of cassava starch granules: A study based on thermogravimetric analysis of aqueous suspensions and humid powders.

    Science.gov (United States)

    Ayala Valencia, Germán; Djabourov, Madeleine; do Amaral Sobral, Paulo José

    2016-08-20

    This work reports on water desorption from cassava starch in relation with the structure and conditioning of granules in suspensions or after equilibration in desiccators. The experimental work is performed by thermogravimetric analysis with isothermal and non-isothermal protocols and interpreted to derive the activation energies and desorption frequencies according to the humidity range with no adjustable parameter. The analysis points out the different types of water interacting with the starch granules and relates the drying coefficients to their microscopic structure. The work helps clarifying contradictory and partial results from the literature.

  16. Water desorption of cassava starch granules: A study based on thermogravimetric analysis of aqueous suspensions and humid powders.

    Science.gov (United States)

    Ayala Valencia, Germán; Djabourov, Madeleine; do Amaral Sobral, Paulo José

    2016-08-20

    This work reports on water desorption from cassava starch in relation with the structure and conditioning of granules in suspensions or after equilibration in desiccators. The experimental work is performed by thermogravimetric analysis with isothermal and non-isothermal protocols and interpreted to derive the activation energies and desorption frequencies according to the humidity range with no adjustable parameter. The analysis points out the different types of water interacting with the starch granules and relates the drying coefficients to their microscopic structure. The work helps clarifying contradictory and partial results from the literature. PMID:27178961

  17. The thermal, rheological and structural properties of cassava starch granules modified with hydrochloric acid at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Beninca, Cleoci; Colman, Tiago Andre Denck [State University of Ponta Grossa - UEPG, Av. Carlos Cavalcanti, 4748, ZIP 84030-900, Ponta Grossa, PR (Brazil); Lacerda, Luiz Gustavo; Filho, Marco Aurelio Silva Carvalho [Positivo University, Curitiba, PR (Brazil); Bannach, Gilbert [Paulista State University - UNESP, Bauru, SP (Brazil); Schnitzler, Egon, E-mail: egons@uepg.br [State University of Ponta Grossa - UEPG, Av. Carlos Cavalcanti, 4748, ZIP 84030-900, Ponta Grossa, PR (Brazil)

    2013-01-20

    Highlights: Black-Right-Pointing-Pointer Untreated cassava starch was modified with standard hydrochloric acid at 20 and 50 Degree-Sign C by 8 h. Black-Right-Pointing-Pointer DSC curves allowed to verify increase in the gelatinization enthalpy in agreement with high temperature. Black-Right-Pointing-Pointer Pasting properties of the studied starches were inversely proportional to the acid treatment and increased temperature. Black-Right-Pointing-Pointer The morphology of granules as well as average size and average roughness were calculated by NC-AFM. - Abstract: Starch is arguably one of the most actively investigated biopolymer in the world. In this study, the native (untreated) cassava starch granules (Manihot esculenta, Crantz) were hydrolyzed by standard hydrochloric acid solution at different temperatures (30 Degree-Sign C and 50 Degree-Sign C) and the hydrolytic transformations were investigated by the following techniques: simultaneous thermogravimetry-differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), as well as non-contact atomic force microscopy (NC-AFM), X-ray diffraction (XRD) powder patterns, and rapid viscoamylographic analysis (RVA). After the treatment with hydrochloric acid at different temperatures, the thermal stability, a gradual loss of pasting properties (viscosity), alterations in the gelatinization enthalpy ({Delta}H{sub gel}), were observed. The use of NC-AFM and XRD allowed the observation of the surface morphology and topography of the starch granules and changes in crystallinity of the granules, respectively.

  18. The thermal, rheological and structural properties of cassava starch granules modified with hydrochloric acid at different temperatures

    International Nuclear Information System (INIS)

    Highlights: ► Untreated cassava starch was modified with standard hydrochloric acid at 20 and 50 °C by 8 h. ► DSC curves allowed to verify increase in the gelatinization enthalpy in agreement with high temperature. ► Pasting properties of the studied starches were inversely proportional to the acid treatment and increased temperature. ► The morphology of granules as well as average size and average roughness were calculated by NC-AFM. - Abstract: Starch is arguably one of the most actively investigated biopolymer in the world. In this study, the native (untreated) cassava starch granules (Manihot esculenta, Crantz) were hydrolyzed by standard hydrochloric acid solution at different temperatures (30 °C and 50 °C) and the hydrolytic transformations were investigated by the following techniques: simultaneous thermogravimetry–differential thermal analysis (TG–DTA), differential scanning calorimetry (DSC), as well as non-contact atomic force microscopy (NC-AFM), X-ray diffraction (XRD) powder patterns, and rapid viscoamylographic analysis (RVA). After the treatment with hydrochloric acid at different temperatures, the thermal stability, a gradual loss of pasting properties (viscosity), alterations in the gelatinization enthalpy (ΔHgel), were observed. The use of NC-AFM and XRD allowed the observation of the surface morphology and topography of the starch granules and changes in crystallinity of the granules, respectively.

  19. Swelling properties of cassava starch grafted with poly (potassium acrylate-co-acrylamide) superabsorbent hydrogel prepared by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Barleany, Dhena Ria, E-mail: dbarleany@yahoo.com; Ulfiyani, Fida; Istiqomah, Shafina; Rahmayetty [Department of Chemical Engineering, University of Sultan Ageng Tirtayasa, Cilegon, Banten (Indonesia); Heriyanto, Heri; Erizal [Centre for Application of Isotopes and Radiation, Jakarta (Indonesia)

    2015-12-29

    Natural and synthetic hydrophylic polymers can be phisically or chemically cross-linked in order to produce hydrogels. Starch based hydrogels grafted with copolymers from acrylic acid or acrylamide have become very popular for water absorbent application. Superabsorbent hydrogels made from Cassava starch grafted with poly (potassium acrylate-co-acrylamide) were prepared by using of ϒ-irradiation method. Various important parameters such as irradiation doses, monomer to Cassava starch ratio and acrylamide content were investigated. The addition of 7,5 % w w{sup −1} acrylamide into the reaction mixture generated a starch graft copolymer with a water absorption in distilled water as high as 460 g g{sup −1} of its dried weight. The effectivity of hydrogel as superabsorbent for aqueous solutions of NaCl and urea was evaluated. The obtained hydrogel showed the maximum absorptions of 317 g g{sup −1} and 523 g g{sup −1} for NaCl and urea solution, respectively (relative to its own dry weight). The structure of the graft copolymer was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM)

  20. Swelling properties of cassava starch grafted with poly (potassium acrylate-co-acrylamide) superabsorbent hydrogel prepared by ionizing radiation

    Science.gov (United States)

    Barleany, Dhena Ria; Ulfiyani, Fida; Istiqomah, Shafina; Heriyanto, Heri; Rahmayetty, Erizal

    2015-12-01

    Natural and synthetic hydrophylic polymers can be phisically or chemically cross-linked in order to produce hydrogels. Starch based hydrogels grafted with copolymers from acrylic acid or acrylamide have become very popular for water absorbent application. Superabsorbent hydrogels made from Cassava starch grafted with poly (potassium acrylate-co-acrylamide) were prepared by using of ϒ-irradiation method. Various important parameters such as irradiation doses, monomer to Cassava starch ratio and acrylamide content were investigated. The addition of 7,5 % w w-1 acrylamide into the reaction mixture generated a starch graft copolymer with a water absorption in distilled water as high as 460 g g-1 of its dried weight. The effectivity of hydrogel as superabsorbent for aqueous solutions of NaCl and urea was evaluated. The obtained hydrogel showed the maximum absorptions of 317 g g-1 and 523 g g-1 for NaCl and urea solution, respectively (relative to its own dry weight). The structure of the graft copolymer was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM).

  1. Swelling properties of cassava starch grafted with poly (potassium acrylate-co-acrylamide) superabsorbent hydrogel prepared by ionizing radiation

    International Nuclear Information System (INIS)

    Natural and synthetic hydrophylic polymers can be phisically or chemically cross-linked in order to produce hydrogels. Starch based hydrogels grafted with copolymers from acrylic acid or acrylamide have become very popular for water absorbent application. Superabsorbent hydrogels made from Cassava starch grafted with poly (potassium acrylate-co-acrylamide) were prepared by using of ϒ-irradiation method. Various important parameters such as irradiation doses, monomer to Cassava starch ratio and acrylamide content were investigated. The addition of 7,5 % w w−1 acrylamide into the reaction mixture generated a starch graft copolymer with a water absorption in distilled water as high as 460 g g−1 of its dried weight. The effectivity of hydrogel as superabsorbent for aqueous solutions of NaCl and urea was evaluated. The obtained hydrogel showed the maximum absorptions of 317 g g−1 and 523 g g−1 for NaCl and urea solution, respectively (relative to its own dry weight). The structure of the graft copolymer was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM)

  2. Effects of Ultrasound on Crystallization of Cassava Starch%超声波作用对木薯淀粉颗粒结晶的影响

    Institute of Scientific and Technical Information of China (English)

    蓝丽红; 李冬雪; 陈阿明; 封余贤; 蓝平; 廖安平

    2012-01-01

    [目的]为了研究超声波作用对木薯淀粉结结晶结构的影响.[方法]用偏光显微镜对超声波作用后的木薯淀粉进行表征.[结果]超声波处理木薯淀粉的最佳条件为:以浓度5%硫酸钠溶液为溶剂,木薯淀粉悬浮液中淀粉含量为16.7%,功率为400W,作用时间300s.经超声作用的木薯淀粉颗粒的偏光十字特征减弱或消失,木薯淀粉颗粒的结晶结构减弱或消失.[结论]超声作用破坏了淀粉的结晶结构,颗粒表面与反应试剂的接触面积增多,从而提高了反应活性.%[Objective] The research aimed to study the effects of ultrasound on the particle shape of cassava starch. [ Method ] Polarizing microscope was used to study cassava starch treated by ultrasound. [Result] The optimum ultrasonic treatment of cassava starch was as follows: 5% sodium sulfate as solvent, content of cassava starch 16.7% , ultrasonic power 400 W and lmdation time 300 s. The cross-polarized state of cassava starch granules showed weakening or disappearance and cassava starch granules crystal structure reduced or lost. [ Conclusion] Ultrasonic ir-ridation destroyed the crystalline structure of starch, and increased its contact area of particle surface and reactivity.

  3. Effect of resistant starch on the cooking quality of yam (Dioscorea spp.) and cassava (Manihot esculenta) based paste products.

    Science.gov (United States)

    Kouadio, Olivier Kouadio; N'dri, Denis Yao; Nindjin, Charlemagne; Marti, Alessandra; Casiraghi, Maria Cristina; Faoro, Franco; Erba, Daniela; Bonfoh, Bassirou; Amani, N'guessan Georges

    2013-06-01

    Total starch (TS) and resistant starch (RS) contents in pasty edible product of mealy and hard cooking tubers of three yam varieties and four cassava varieties were determined to evaluate their contribution in their cooking quality. TS and RS contents appeared as the main components in determining yam cooking quality. Mealy cooking yam varieties were characterized by a significant higher TS content (75.2 ± 7.7 g/100 g d.m.) and lower RS content (13.8 ± 3.4 g/100 g d.m.) than hard cooking yam varieties, which, in contrast, contained less TS (61.7 ± 12.1 g/100 g d.m.) and particularly high RS (21.8 ± 9.9 g/100 g d.m.), possibly as a consequence of the prevalence of large granules (35-40 μm) observed by light microscope. Conversely, TS and RS contents appeared not determinant on the cooking quality of cassava. Moreover, higher amylose contents were associated with substantially elevated percentages of RS in yam and cassava, and high RS content in samples modulates their pasting properties by reducing the peak viscosity and the breakdown and requiring higher temperature and longer time to the peak.

  4. Effect of jute and kapok fibers on properties of thermoplastic cassava starch composites

    International Nuclear Information System (INIS)

    Highlights: ► TPCS matrix was reinforced by the low (jute) and high (kapok) absorbency cellulosic fibers. ► Water absorption of the TPCS/jute and TPCS/kapok fiber composites decreases. ► Stress and Young’s modulus of the TPCS/jute and TPCS/kapok fiber composites increase. ► Thermal degradation temperature of the TPCS/kapok fiber composite decreases. - Abstract: Since mechanical properties and water uptake of biodegradable thermoplastic cassava starch (TPCS) was still the main disadvantages for many applications. The TPCS matrix was, therefore, reinforced by two types of cellulosic fibers, i.e. jute or kapok fibers; classified as the low and high oil absorbency characteristics, respectively. The TPCS, plasticized by glycerol, was compounded by internal mixer and shaped by compression molding machine. It was found that water absorption of the TPCS/jute fiber and TPCS/kapok fiber composites was clearly reduced by the addition of the cellulosic fibers. Moreover, stress at maximum load and Young’s modulus of the composites increased significantly by the incorporation of both jute and kapok fibers. Thermal degradation temperature, determined from thermogravimetric analysis (TGA), of the TPCS matrix increased by the addition of jute fibers; however, thermal degradation temperature decreased by the addition of kapok fibers. Functional group analysis and morphology of the TPCS/jute fiber and TPCS/kapok fiber composites were also examined using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) techniques

  5. Acidification and starch behaviour during co-fermentation of cassava (Manihot esculenta Crantz) and soybean (Glycine max Merr) into gari, an African fermented food.

    Science.gov (United States)

    Afoakwa, Emmanuel Ohene; Kongor, Edem John; Annor, George Amponsah; Adjonu, Randy

    2010-08-01

    Changes in acidification and starch behaviour were investigated during co-fermentation of cassava and soybean into gari, an African fermented product. Non-volatile acidity, pH and starch content were evaluated using standard analytical methods. Starch breakdown and pasting characteristics were also analysed using a Brabender viscoamylograph. Fermentation caused significant variations in the pH, non-volatile acidity and starch concentration. The pH decreased with concomitant increases in non-volatile acidity during co-fermentation of the cassava dough. Soy fortification up to 20% caused only minimal effects on the pH, titratable acidity and starch content during the fermentation period. Starch content decreased from 69.8% to 60.4% within the 48 h fermentation time in the unfortified sample, with similar trends noted at all levels of fortification. Starch pasting characteristics showed varied trends in pasting temperature, peak viscosity, viscosity at 95 degrees C and at 50 degrees C-hold with increasing fermentation time and soybean concentration. Cassava could be co-fermented with soybean up to 20% concentration during gari processing without significant effect on its process and product quality characteristics.

  6. 酸解木薯淀粉及其软糖性能研究%Study on properties of acid hydrolysis cassava starch and its jelly candy

    Institute of Scientific and Technical Information of China (English)

    范浩然; 熊柳; 孙庆杰

    2013-01-01

    The acid hydrolysis of cassava starches were prepared using cassava starch as material, treating starch with 6%HCl at 50℃for different durations(0 min,30 min,60 min,90 min). At the same time the acid hydrolysis of cassava starches were used to produce cassava starch jelly candy. The properties of the acid hydrolysis of cassava starch were investigated by determining the gelatinization and texture properties and assay the tensile properties and texture properties of the acid hydrolysis cassava starch jelly candy. The results showed that a significant decrease in starch viscosity and set back and an increase in hardness with increase in acid hydrolysis. The tensile properties of jelly candy with three different hydrolysis time all accord with industrial production index. The jelly candy with 60 min acid hydrolysis of cassava starch was better on hardness,adhesiveness,chewiness and resilience.%  以木薯淀粉为原料,在50℃下,用6%HCl对木薯淀粉进行不同时间(0 min、30 min、60 min、90 min)酸解改性,制备酸解木薯淀粉,并对酸解淀粉糊化特性和质构特性进行研究与分析;同时采用酸解木薯淀粉制备软糖,对制得酸解木薯淀粉软糖进行拉伸与质构分析.实验结果表明,随酸解时间增加;酸解木薯淀粉最低粘度、峰值粘度、回生值显著降低,淀粉凝胶硬度显著增加.3个不同水解时间木薯软糖拉伸率均符合工业生产指标,60 min酸解木薯淀粉制备软糖硬度适中,胶粘性、咀嚼性、回复性良好.

  7. Isolation and characterization of two soil derived yeasts for bioethanol production on Cassava starch

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Gi-Wook; Kim, Yule; Kang, Hyun-Woo [Changhae Institute of Cassava and Ethanol Research, Changhae Ethanol Co., Ltd, Palbok-Dong 829, Dukjin-Gu, Jeonju 561-203 (Korea); Um, Hyun-Ju; Kim, Mina; Kim, Yang-Hoon [Department of Microbiology, Chungbuk National University, 410 Sungbong-Ro, Heungduk-Gu, Cheongju 361-763 (Korea); Chung, Bong-Woo [Department of Bioprocess Engineering, Chonbuk National University, 664-14, 1-Ga, Duckjin-Dong, Duckjin-Gu, Jeonju 561-156 (Korea)

    2010-08-15

    Two ethanol-producing yeast strains, CHY1011 and CHFY0901 were isolated from soil in South Korea using an enrichment technique in a yeast peptone dextrose medium supplemented with 5% (w v{sup -1}) ethanol at 30 C. The phenotypic and physiological characteristics, as well as molecular phylogenetic analysis based on the D1/D2 domains of the large subunit (26S) rRNA gene and the internally transcribed spacer (ITS) 1 + 2 regions suggested that they were novel strains of Saccharomyces cerevisiae. During shaking flask cultivation, the highest ethanol productivity and theoretical yield of S. cerevisiae CHY1011 in YPD media containing 9.5% total sugars was 1.06 {+-} 0.02 g l{sup -1} h{sup -1} and 95.5 {+-} 1.2%, respectively, while those for S. cerevisiae CHFY0901 were 0.97 {+-} 0.03 g l{sup -1} h{sup -1} and 91.81 {+-} 2.2%, respectively. Simultaneous saccharification and fermentation for ethanol production was carried out using liquefied cassava (Manihot esculenta) starch in a 5 l lab-scale jar fermenter at 32 C for 66 h with an agitation speed of 2 Hz. Under these conditions, S. cerevisiae CHY1011 and CHFY0901 yielded a final ethanol concentration of 89.1 {+-} 0.87 g l{sup -1} and 83.8 {+-} 1.11 g l{sup -1}, a maximum ethanol productivity of 2.10 {+-} 0.02 g l{sup -1} h{sup -1} and 1.88 {+-} 0.01 g l{sup -1} h{sup -1}, and a theoretical yield of 93.5 {+-} 1.4% and 91.3 {+-} 1.1%, respectively. These results suggest that S. cerevisiae CHY1011 and CHFY0901 have potential use in industrial bioethanol fermentation processes. (author)

  8. Biocomposite of Cassava Starch Reinforced with Cellulose Pulp Fibers Modified with Deposition of Silica (SiO2 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Joabel Raabe

    2015-01-01

    Full Text Available Eucalyptus pulp cellulose fibers were modified by the sol-gel process for SiO2 superficial deposition and used as reinforcement of thermoplastic starch (TPS. Cassava starch, glycerol, and water were added at the proportion of 60/26/14, respectively. For composites, 5% and 10% (by weight of modified and unmodified pulp fibers were added before extrusion. The matrix and composites were submitted to thermal stability, tensile strength, moisture adsorption, and SEM analysis. Micrographs of the modified fibers revealed the presence of SiO2 nanoparticles on fiber surface. The addition of modified fibers improved tensile strength in 183% in relation to matrix, while moisture adsorption decreased 8.3%. Such improvements were even more effective with unmodified fibers addition. This result was mainly attributed to poor interaction between modified fibers and TPS matrix detected by SEM analysis.

  9. Study on Preparation for Cassava Starch Acetate with Low Degree of Substitution Using Mechanical Activated Cassava Starch%机械活化木薯淀粉制备低取代度醋酸酯淀粉的研究

    Institute of Scientific and Technical Information of China (English)

    陈渊; 杨家添; 朱万仁; 韦庆敏; 何军

    2014-01-01

    The cassava starch acetate of low degree of substitution were preparation using mechanical activated cassava starch which was mechanical activated for half an hour and the native starch as material acetic anhydride as acetylation reagent and sodium hydroxide as catalyst. The effects of reaction temperature, the reaction time, acetic anhydride amount and pH value on esterification of cassava starch were investigated respectively by using degree of substitution (DS) and reaction efficiency (RE)of starch acetate as evaluating parameter. The results showed that reaction temperature, the reaction time, acetic anhydride amount and pH value had certain effect on the DS and the RE of starch acetate. Mechanical activation can significantly increase the DS and the RE of starch acetate. The optimal technical conditions were obtained as reaction temperature 30℃, reaction time 40 minutes, acetic anhydride amount 0.15 mL, pH value 8.5. Under the conditions, the DS in the products was 0.075, and the RE was 87.45 %. Furthermore, the structure of activated starch and the starch acetate were further characterized by using FTIR.%以机械活化0.5 h的木薯淀粉和木薯原淀粉为原料,以醋酸酐为酯化试剂,氢氧化钠为催化剂,制备低取代度木薯淀粉醋酸酯。以淀粉醋酸酯的取代度和反应效率为评价指标,分别研究反应温度、反应时间、醋酸酐用量、pH各因素对其取代度和反应效率的影响。实验结果表明,反应温度、反应时间、醋酸酐用量、pH对木薯淀粉醋酸酯的取代度和反应效率均有影响。机械活化能显著提高木薯淀粉醋酸酯化反应的取代度和反应效率。通过试验得到制备低取代度木薯淀粉醋酸酯的较佳工艺条件为:反应温度为30℃,反应时间为40 min,醋酸酐用量为0.15 mL,pH为8.5时,在此条件下制备的醋酸酯淀粉的取代度为0.075、反应效率为87.45%。并用红外光谱对醋酸酯淀粉进行分析。

  10. Isolation and characterisation of starch biosynthesis genes from cassava (Manihot esculenta Crantz).

    NARCIS (Netherlands)

    Munyikwa, T.R.I.

    1997-01-01

    Cassava (Manihot esculenta Crantz) is a tropical crop grown for its starchy thickened roots, mainly by peasant farmers, in the tropics, for whom it is a staple food. There is an increasing demand for the use of cassava in processed food and feed products, and in the paper and textile industries amon

  11. Graft copolymerization of acrylic acid to cassava starch-Evaluation of the influences of process parameters by an experimental design method

    NARCIS (Netherlands)

    Witono, J. R.; Noordergraaf, I. W.; Heeres, H. J.; Janssen, L. P. B. M.

    2012-01-01

    The graft copolymerization of cassava starch with acrylic acid was investigated using a free radical initiator system (Fe2+/H2O2 redox system) in water. A comprehensive understanding of the important variables and their interaction has been obtained by applying an experimental design method. In this

  12. Synthesis of an air-working trilayer artificial muscle using a conductive cassava starch biofilm (manihot esculenta, cranz) and polypyrrole (PPy)

    Science.gov (United States)

    Núñez D, Y. E.; Arrieta A, Á. A.; Segura B, J. A.; Bertel H, S. D.

    2016-02-01

    In this study, a methodology for obtaining a conductive cassava starch biofilm doped with lithium perchlorate (LiClO4) is shown, as well as the electrochemical technique for the synthesis of polypyrrole films, which are used for developing the trilayer artificial muscle PPy/Biopolymer/PPy designed to operate in air. Furthermore, results from the trilayer movement using chronoamperometric techniques are shown.

  13. Enhancement of the grafting performance and of the water absorption of cassava starch graft copolymer by gamma radiation

    International Nuclear Information System (INIS)

    Enhancement of the gamma radiation grafting of acrylonitrile onto gelatinized cassava starch was investigated. Infrared spectrometry was used to follow the chemical changes in the grafting reaction and from saponification. The saponified starch-g-PAN (HSPAN) was then characterized in terms of grafting parameters to provide a guide for the optimum total dose (kGy) and the appropriate ratio of starch/acrylonitrile for a fixed dose rate of 2.5 x 10-1 kGy/min. Other dose rates were also carried out to obtain the appropriate result of grafting copolymerization and of water absorption. A thin aluminium foil, covering the inner wall of the reaction vessel, was found to be far more effective than any other metal films in the enhancement of the grafting reaction and the water absorption as well. Nitric acid in the medium increases the grafting yield and the water absorption. Methyl ether hydroquinone inhibitor was evaluated for its ability to increase homopolymerization and decrease graft reaction. When styrene was used as a comonomer, it hampered the grafting of acrylonitrile onto starch backbone. The water absorption capacity was improved by freeze-drying the HSPAN. The treatment of the HSPAN with aluminium trichloride hexahydrate was found to enhance the degree of wicking, but to decrease the water absorbency. (author)

  14. Enhancement of the grafting performance and of the water absorption of cassava starch graft copolymer by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kiatkamjornwong, Suda; Meechai, Nispa [Chulalongkorn Univ., Bangkok (Thailand)

    1997-06-01

    Enhancement of the gamma radiation grafting of acrylonitrile onto gelatinized cassava starch was investigated. Infrared spectrometry was used to follow the chemical changes in the grafting reaction and from saponification. The saponified starch-g-PAN (HSPAN) was then characterized in terms of grafting parameters to provide a guide for the optimum total dose (kGy) and the appropriate ratio of starch/acrylonitrile for a fixed dose rate of 2.5 x 10{sup -1} kGy/min. Other dose rates were also carried out to obtain the appropriate result of grafting copolymerization and of water absorption. A thin aluminium foil, covering the inner wall of the reaction vessel, was found to be far more effective than any other metal films in the enhancement of the grafting reaction and the water absorption as well. Nitric acid in the medium increases the grafting yield and the water absorption. Methyl ether hydroquinone inhibitor was evaluated for its ability to increase homopolymerization and decrease graft reaction. When styrene was used as a comonomer, it hampered the grafting of acrylonitrile onto starch backbone. The water absorption capacity was improved by freeze-drying the HSPAN. The treatment of the HSPAN with aluminium trichloride hexahydrate was found to enhance the degree of wicking, but to decrease the water absorbency. (author).

  15. Effect of thermal and chemical modiifcations on the mechanical and release properties of paracetamol tablet formulations containing corn, cassava and sweet potato starches as ifller-binders

    Institute of Scientific and Technical Information of China (English)

    Mariam Vbamiunomhene Lawal; Michael Ayodele Odeniyi; Oludele Adelanwa Itiola

    2015-01-01

    Objective:To investigate the effects of acetylation and pregelatinization of cassava and sweet potato starches on the mechanical and release properties of directly compressed paracetamol tablet formulations in comparison with official corn starch. Methods: The native starches were modified by acetylation and pregelatinization. The tablets were assessed using friability (Fr), crushing strength (Cs), disintegration time (Dt) and dissolution parameters. Results: Starch acetylation produced paracetamol tablets that were stronger and had the best balance of mechanical and disintegration properties, while pregelatinization produced tablets that were more friable but had a better overall strength in relation to disintegration than formulations made from natural starches. Correlations mainly existed between Dt and the dissolution parameters t80, t2 and k1 in the formulations. Conclusions:Modification of the experimental starches improved the mechanical and release properties of directly compressed paracetamol tablet formulations. Thus, they can be developed for use as pharmaceutical excipients in specific formulations.

  16. Effect of thermal and chemical modifications on the mechanical and release properties of paracetamol tablet formulations containing corn, cassava and sweet potato starches as filler-binders

    Institute of Scientific and Technical Information of China (English)

    Mariam; Vbamiunomhene; Lawal; Michael; Ayodele; Odeniyi; Oludele; Adelanwa; Itiola

    2015-01-01

    Objective: To investigate the effects of acetylation and pregelatinization of cassava and sweet potato starches on the mechanical and release properties of directly compressed paracetamol tablet formulations in comparison with official corn starch.Methods: The native starches were modified by acetylation and pregelatinization. The tablets were assessed using friability(Fr), crushing strength(Cs), disintegration time(Dt) and dissolution parameters. Results: Starch acetylation produced paracetamol tablets that were stronger and had the best balance of mechanical and disintegration properties, while pregelatinization produced tablets that were more friable but had a better overall strength in relation to disintegration than formulations made from natural starches. Correlations mainly existed between Dt and the dissolution parameters t80, t2 and k1 in the formulations. Conclusions: Modification of the experimental starches improved the mechanical and release properties of directly compressed paracetamol tablet formulations. Thus, they can be developed for use as pharmaceutical excipients in specific formulations.

  17. 机械活化木薯淀粉的光谱分析%Spectrum Analysis of Mechanical Activated Cassava Starch

    Institute of Scientific and Technical Information of China (English)

    孙丹丹; 张宏伟

    2012-01-01

    采用机械活化的方法对木薯淀粉进行处理,利用X射线衍射、红外光谱及激光光谱等方法对处理后木薯淀粉的结晶结构、分子基团和粒径分布进行分析。研究结果表明,机械活化可以有效降低木薯淀粉颗粒的粒径,且粒径线性回归的趋势分布随活化时间不同而迁移,机械活化能破坏木薯淀粉的结晶结构,在X射线衍射图上表现为结晶衍射峰消失,机械活化可以增加木薯淀粉中反应基团游离羟基的数量,尤其使伯羟基的数量增加。%Cassava starch was processed by mechanical activation.Crystal structure,molecular group and particle size distribution of processed cassava starch were studied by X-ray diffraction,infrared spectroscopy and laser spectroscopy.The results showed that particle size of cassava starch could be reduced effectively by mechanical activation,and distribution of its linear regression trend was shifted with different activation time.Mechanical activation energy could destroy crystal structure of cassava starch,shown as disappearance of crystal diffraction peak in the X-ray diffraction diagram.And mechanical activation could increase the number of reactive free hydroxyl of cassava starch,especially primary hydroxyl.

  18. Phylogeny and expression pattern of starch branching enzyme family genes in cassava (Manihot esculenta Crantz) under diverse environments.

    Science.gov (United States)

    Pei, Jinli; Wang, Huijun; Xia, Zhiqiang; Liu, Chen; Chen, Xin; Ma, Pingan; Lu, Cheng; Wang, Wenquan

    2015-08-01

    Starch branching enzyme (SBE) is one of the key enzymes involved in starch biosynthetic metabolism. In this study, six SBE family genes were identified from the cassava genome. Phylogenetic analysis divided the MeSBE family genes into dicot family A, B, C, and the new group. Tissue-specific analysis showed that MeSBE2.2 was strongly expressed in leaves, stems cortex, and root stele, and MeSBE3 had high expression levels in stem cortex and root stele of plants in the rapid growth stage under field condition, whereas the expression levels of MeSBE2.1, MeSBE4, and MeSBE5 were low except for in stems cortex. The transcriptional activity of MeSBE2.2 and MeSBE3 was higher compared with other members and gradually increased in the storage roots during root growth process, while the other MeSBE members normally remained low expression levels. Expression of MeSBE2.2 could be induced by salt, drought, exogenous abscisic acid, jasmonic acid, and salicylic acid signals, while MeSBE3 had positive response to drought, salt, exogenous abscisic acid, and salicylic acid in leaves but not in storage root, indicating that they might be more important in starch biosynthesis pathway under diverse environments.

  19. Semi-continuous production of 2-keto-gluconic acid by Pseudomonas fluorescens AR4 from rice starch hydrolysate.

    Science.gov (United States)

    Sun, Wen-Jing; Zhou, Yan-Zheng; Zhou, Qiang; Cui, Feng-Jie; Yu, Shi-Lian; Sun, Lei

    2012-04-01

    2-Keto-gluconic acid (2KGA) was produced in a semi-continuous process using Pseudomonas fluorescens AR4 and rice starch hydrolysate (RSH). The bacterium was cultured in medium with an initial glucose concentration of 170g/L supplied as RSH. Once the glucose level had dropped to 20g/L, 60% of the culture volume was replaced with fresh medium containing 190g/L of glucose in the form of RSH. After an additional two cycles of growth and media replacement, a total of 476.88g/L of glucose was consumed and 444.96g/L of 2KGA was produced. A total productivity of 6.74g/L and a yield of 0.93g/g were obtained. These findings suggest that P. fluorescens AR4 is suitable for the production of commercially acceptable levels of 2KGA in semi-continuous culture.

  20. Study on Preparation and Properties of Cross-Linking and Esterifying Starch of Mechanical Activated Cassava Starch%机械活化木薯交联酯化淀粉的制备及其性能研究

    Institute of Scientific and Technical Information of China (English)

    陈渊; 杨家添; 谢祖芳; 谭义秋; 黄祖强; 周琴

    2012-01-01

    Cross - linking and esterifying starch of mechanical activated cassava starch was prepared by using mechanical activated cassava starch as raw material, and using sodium trimetaphosophate for cross - linking agent and acetic anhydride for acetification, which its synthesis route prepared by continual reactions in one - step synthesis way. The effects of reaction temerature, cross - linking agent and esterifying agent dosage, pH value of cross — linking and esterifying and cross - linking time on the cold viscosity of cross - linking and esterifying starch paste were investigated respectively, and the physical and chemical Parameters and structure of the cross - linking and esterifying starch with mechanical activated cassava starch and cross - linking and esterifying starch with raw cassava starch were studied. The results indicated that the above reaction conditions were all found to affect the preparation of cross - linking and esterifying mechanical activated cassava starch. Under the reaction temperature 40℃ ,1.0% amounts of sodium trimetaphosphate,crosslinking pH value 10.0,crosslinking time 2. 0 h,acetic anhydride amount 0. 5 mL,esterifying pH value 9.0, esterifying time 60 min, the cold viscosity of cross - linking and esterifying starch paste of mechanical activated cassava was enhanced from 847 mPa. S of cassava starch to 3 225 mPa. S, and the stability, acidity - resistance, staling resistance of the viscosity of starch paste were significantly improved. Cross - linking and esterifying composite modified was propitious to formation of V type crystal starch.%以机械活化木薯淀粉为原料,三偏磷酸钠为交联剂,醋酸酐为酯化剂,采用一步连续法制备机械活化木薯交联酯化淀粉,考察反应温度、交联剂用量、交联pH、交联时间、酯化剂用量、酯化pH、酯化时间等因素对交联酯化淀粉糊冷黏度的影响,并与原木薯淀粉合成的交联酯化淀粉进行比较,研究了产物的理化特性

  1. Production of raw starch-degrading enzyme by Aspergillus sp. and its use in conversion of inedible wild cassava flour to bioethanol.

    Science.gov (United States)

    Moshi, Anselm P; Hosea, Ken M M; Elisante, Emrode; Mamo, Gashaw; Önnby, Linda; Nges, Ivo Achu

    2016-04-01

    The major bottlenecks in achieving competitive bioethanol fuel are the high cost of feedstock, energy and enzymes employed in pretreatment prior to fermentation. Lignocellulosic biomass has been proposed as an alternative feedstock, but because of its complexity, economic viability is yet to be realized. Therefore, research around non-conventional feedstocks and deployment of bioconversion approaches that downsize the cost of energy and enzymes is justified. In this study, a non-conventional feedstock, inedible wild cassava was used for bioethanol production. Bioconversion of raw starch from the wild cassava to bioethanol at low temperature was investigated using both a co-culture of Aspergillus sp. and Saccharomyces cerevisiae, and a monoculture of the later with enzyme preparation from the former. A newly isolated strain of Aspergillus sp. MZA-3 produced raw starch-degrading enzyme which displayed highest activity of 3.3 U/mL towards raw starch from wild cassava at 50°C, pH 5.5. A co-culture of MZA-3 and S. cerevisiae; and a monoculture of S. cerevisiae and MZA-3 enzyme (both supplemented with glucoamylase) resulted into bioethanol yield (percentage of the theoretical yield) of 91 and 95 at efficiency (percentage) of 84 and 96, respectively. Direct bioconversion of raw starch to bioethanol was achieved at 30°C through the co-culture approach. This could be attractive since it may significantly downsize energy expenses.

  2. Production of raw starch-degrading enzyme by Aspergillus sp. and its use in conversion of inedible wild cassava flour to bioethanol.

    Science.gov (United States)

    Moshi, Anselm P; Hosea, Ken M M; Elisante, Emrode; Mamo, Gashaw; Önnby, Linda; Nges, Ivo Achu

    2016-04-01

    The major bottlenecks in achieving competitive bioethanol fuel are the high cost of feedstock, energy and enzymes employed in pretreatment prior to fermentation. Lignocellulosic biomass has been proposed as an alternative feedstock, but because of its complexity, economic viability is yet to be realized. Therefore, research around non-conventional feedstocks and deployment of bioconversion approaches that downsize the cost of energy and enzymes is justified. In this study, a non-conventional feedstock, inedible wild cassava was used for bioethanol production. Bioconversion of raw starch from the wild cassava to bioethanol at low temperature was investigated using both a co-culture of Aspergillus sp. and Saccharomyces cerevisiae, and a monoculture of the later with enzyme preparation from the former. A newly isolated strain of Aspergillus sp. MZA-3 produced raw starch-degrading enzyme which displayed highest activity of 3.3 U/mL towards raw starch from wild cassava at 50°C, pH 5.5. A co-culture of MZA-3 and S. cerevisiae; and a monoculture of S. cerevisiae and MZA-3 enzyme (both supplemented with glucoamylase) resulted into bioethanol yield (percentage of the theoretical yield) of 91 and 95 at efficiency (percentage) of 84 and 96, respectively. Direct bioconversion of raw starch to bioethanol was achieved at 30°C through the co-culture approach. This could be attractive since it may significantly downsize energy expenses. PMID:26481161

  3. Adsorption of lead (II) ions onto novel cassava starch 5-choloromethyl-8-hydroxyquinoline polymer from an aqueous medium.

    Science.gov (United States)

    Shah, Prapti U; Raval, Nirav P; Vekariya, Mayur; Wadhwani, Poonam M; Shah, Nisha K

    2016-01-01

    Adsorption of lead (II) ions onto cassava starch 5-choloromethyl-8-hydroxyquinoline polymer (CSCMQ) was investigated with the variation in the parameters of pH, contact time, lead (II) ions concentration, temperature and the adsorbent dose. The Langmuir and Freundlich models have been applied. CSCMQ was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Results showed that the adsorption process was better described by the Langmuir model. Adsorption kinetics data obtained for the metal ions sorption were investigated using pseudo-first-order, pseudo-second-order and intraparticle diffusion model. The maximum adsorption capacities (qm) were 46.512, 43.859 and 42.735 mg/g at 25, 35 and 45 °C, respectively. The dynamical data fit well with the second-order kinetics model. The results indicate that CSCMQ could be employed as low-cost material for the adsorption of Pb(II) ions from aqueous medium. PMID:27533869

  4. Research on the Physicochemical Property of the Starch in Different Cassava Varieties%不同品种的木薯淀粉理化特性研究

    Institute of Scientific and Technical Information of China (English)

    杨栋林; 陈燕珍; 庞月圆; 刘晓灿; 谭涛

    2009-01-01

    [Objective] The physical and chemical characteristics of cassava starch was studied.[Method] The cassava variety: bread cassava with large leaf and white skin(DB), bread cassava with small leaf and white skin (XB), bread cassava with large leaf and red skin(DH) being taken as experimental material, the physical and chemical property such as the content of protein, the light transmittance, the stability of frozen and condensation/precipitation, and cassava shape of these varieties was tested.[Results] The order of the content of protein from high to low was: XB>DH>DB;the light transmittance, DB>XB>DH;there was no difference in the stability of frozen and condensation/precipitation among varieties;and there was difference in the cassava shape among varieties.[Conclusion] The scientific reference for the deep processing and development and utilization of cassava was provided.%[目的]研究木薯淀粉的理化特性.[方法]以大叶白皮面包木薯(DB)、小叶白皮面包木薯(XB)、大叶红皮面包木薯(DH)为试验材料,测定其蛋白质含量、透光率、冷冻稳定性、凝沉稳定性及颗粒形态等理化特性.[结果]蛋白质含量的高低为:XB>DH>DB;透光率的大小为:DB>XB>DH;冷冻稳定性及凝沉稳定性差异不大;淀粉的颗粒形态有差异.[结论]试验为木薯的深加工及开发利用提供了科学的参考依据.

  5. Characterization of foams obtained from cassava starch, cellulose fibres and dolomitic limestone by a thermopressing process

    Directory of Open Access Journals (Sweden)

    Vivian Consuelo Reolon Schmidt

    2010-02-01

    Full Text Available Cassava starch, dolomitic limestone and eucalypt cellulose fibres were used to prepare foam trays that could be used to pack foodstuffs. The influence of the cellulose fibre concentration in the composite formulation was investigated using 5, 10, 15, 20, 30 and 40% of fibres. The results indicated that an increase in cellulose fibre concentration promoted a decrease in density and tensile strength of the foam samples. The tensile strength at break for foam trays containing 5% of cellulose fibres was 3.03MPa, whilst the commercial trays of expanded polystyrene used to pack foods in supermarkets presented a tensile strength of 1.49 MPa. The elongation at break of the foam trays obtained in this work varied slightly with increase in cellulose fibre concentration, the values being about 20% lower than the elongation at break observed for commercial foam trays of expanded polystyrene. Thus, the materials developed in this work represented a possible alternative to the use of EPS foam trays for packing dry foods. The trays' properties need to be improved for their use with moist foods.Amido de mandioca, calcário dolomítico e fibras celulósicas de eucalipto foram usados para preparar bandejas biodegradáveis que podem ser usadas como embalagens para alimentos. A influência da concentração de fibras na formulação dos compostos foi investigada, usando 5, 10, 15, 20, 30 e 40% de fibras. Os resultados indicaram que o aumento na concentração de fibras celulósicas promove uma diminuição na densidade e na resistência a tração das amostras. A tensão na ruptura para as bandejas contendo 5% de fibras celulósicas foi de 3,03 MPa, enquanto as bandejas comerciais de poliestireno expandido (EPS usadas para embalagens alimentícias em supermercados apresentaram uma tensão de 1.49 MPa. A elongação na ruptura das bandejas obtidas neste trabalho variou ligeiramente com o aumento da concentração de fibra celulósica, os valores são aproximadamente

  6. THERMOANALYTICAL STUDY OF NATIVE CASSAVA STARCH AND TREATED WITH HYDROGEN PEROXIDE

    OpenAIRE

    Fernanda Janaína Oliveira Gomes da COSTA; Rafael Ramirez de ALMEIDA; Lacerda, Luiz Gustavo; Marco Aurélio da Silva CARVALHO-FILHO; Gilbert BANNACH; Schnitzler, Egon

    2011-01-01

    Starch is one of the most important sources of reserve of carbohydrate in plants and the main source in the human diet due to its abundance in the nature. There no other food ingredient that can be compared with starch in terms of sheer versatility of application in the food industry. Unprocessed native starches are structurally too weak and functionally too restricted for application in today’s advanced food and industrial technologies. The main objective of this stud...

  7. Ninety-Day Oral Toxicity Assessment of an Alternative Biopolymer for Controlled Release Drug Delivery Systems Obtained from Cassava Starch Acetate

    Directory of Open Access Journals (Sweden)

    Douglas Rossi Jesus

    2015-01-01

    Full Text Available The large consumption of biodegradable films from cassava starch acetate (FCSA as ingredients in food and pharmaceutical products requires the assessment of the possible toxicity of these products. The aim of this study was to investigate the toxicity of biodegradable film from cassava starch acetate after oral exposure of Wistar rats for 90 days. The amount of food consumed and the body weight were weekly monitored. Blood and urine samples were obtained for the assessment of serum parameters and renal function. Histopathological analyses in target organs were also performed. No evidence of clinical toxicity in hematological, biochemical, or renal parameters in the FCSA-treated animals was found. In addition, relative organ weight and histopathological evaluations did not differ between groups treated with FCSA and control. Data obtained suggest that the subchronic exposure to FCSA does not cause obvious signs of toxicity in Wistar rats, indicating possible safety of this biofilm.

  8. Response surface optimisation for acetone-butanol-ethanol production from cassava starch by co-culture of Clostridium butylicum and Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Benjamas Cheirsilp

    2011-11-01

    Full Text Available Acetone-butanol-ethanol (ABE production from cassava starch was enhanced by a syntrophic co-culture of Clostridium butylicum TISTR 1032 and high amylase producing Bacillus subtilis WD 161 without anaerobic pretreatment. The production of amylase and ABE using this co-culture were respectively 16 and 6 times higher than those using the pure culture of C. butylicum TISTR 1032. The effect of the medium components on the performance of the co-culture was investigated using response surface methodology (RSM. Among the investigated components, cassava starch and ammonium nitrate contributed a significant effect on the production of amylase and ABE, while yeast extract had less effect. Based on the optimum strategy using RSM, the ABE production by the co-culture was improved 2.2-fold compared with that obtained from the initial condition and with a minimum requirement of nitrogen source.

  9. Cassava starch graft copolymers an eco-friendly corrosion inhibitor for steel in H{sub 2}SO{sub 4} solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xianghong; Deng, Shuduan [Southwest Forestry University, Kunming (China)

    2015-11-15

    Cassava starch graft copolymer (CSGC) was prepared by grafting acryl amide (AA) onto cassava starch (CS). The inhibition effect of CSGC on the corrosion of cold rolled steel (CRS) in 1.0M H{sub 2}SO{sub 4} solution was first studied by weight loss, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM) methods. The results show that CSGC is a good inhibitor, and inhibition efficiency of CSGC is higher than that of CS or AA. The adsorption of CSGC on steel surface obeys Langmuir adsorption isotherm. CSGC is a mixed-type inhibitor at 20 .deg. C, while mainly a cathodic inhibitor at 50 .deg. C.

  10. Experimental Researches on Cassava Starch Wastewater Treatment by Coagulation Sedimentation%絮凝法处理木薯淀粉生产废水试验研究

    Institute of Scientific and Technical Information of China (English)

    王汉林; 刘康怀

    2013-01-01

    Cassava starch wastewater from the processing industry has brought great environmental pollutions . Some experimental researches on cassava starch wastewater treatment were done by coagulation sedimenta-tion.In the experiments three flocculants were used which were:polyferrum,polymeric aluminum and sulfra aliminium,and polyacrylamide was used as concretion -aid agant.Through the analysis of experimental da-tas,the result was obtained that the best conditions of cassava starch wastewater treatment were as follows:pH-7.5,flocculant-polymeric aluminum,concretion-aid agant-polyacrylamide.In this way the cost of cas-sava starch wastewater treatment was only 0.14 yuan per ton.%  木薯淀粉生产加工过程中所产生的生产废水给环境造成了很大的污染。对木薯淀粉生产废水进行了絮凝试验研究。试验分别采用了3种絮凝剂:聚合硫酸铁、聚合氯化铝、精制硫酸铝,助凝剂采用聚丙烯酰胺。通过对试验数据进行分析得出,处理木薯淀粉生产废水的最佳条件是:pH 值为7.5,采用聚合氯化铝作絮凝剂,聚丙烯酰胺为助凝剂,处理每吨废水需花费0.14元。

  11. Dynamics of the microbial community responsible for traditional sour cassava starch fermentation studied by denaturing gradient gel electrophoresis and quantitative rRNA hybridization

    OpenAIRE

    Ampe, Frédéric; Sirvent, A.; Zakhia, N.

    2001-01-01

    The microbial community developing during the spontaneous fermentation of sour cassava starch was investigated by cultivation-independent methods. Denaturing gradient gel electrophoresis (DGGE) of partially amplified 16S rDNA followed by sequencing of the most intense bands showed that the dominant organisms were all lactic acid bacteria (LAB), mainly close relatives of #Bifidobacterium minimum$, #Lactococcus lactis$, #Streptoccocus$ sp., #Enteroccucus saccharolyticus$ and #Lactobacillus plan...

  12. Effect of temperature and relative humidity on the water vapour permeability and mechanical properties of cassava starch and soy protein concentrate based edible films.

    Science.gov (United States)

    Chinma, C E; Ariahu, C C; Alakali, J S

    2015-04-01

    The effect of temperature and relative humidity on the water vapour permeability (WVP) and mechanical properties of cassava starch and soy protein concentrate (SPC) based edible films containing 20 % glycerol level were studied. Tensile strength and elastic modulus of edible films increased with increase in temperature and decreased with increase in relative humidity, while elongation at break decreased. Water vapour permeability of the films increased (2.6-4.3 g.mm/m(2).day.kPa) with increase in temperature and relative humidity. The temperature dependence of water vapour permeation of cassava starch-soy protein concentrate films followed Arrhenius relationship. Activation energy (Ea) of water vapour permeation of cassava starch-soy protein concentrate edible films ranged from 1.9 to 5.3 kJ/mol (R (2)  ≥ 0.93) and increased with increase in SPC addition. The Ea values were lower for the bio-films than for polyvinylidene chloride, polypropylene and polyethylene which are an indication of low water vapour permeability of the developed biofilms compared to those synthetic films.

  13. Effects of Cassava Starch and Natural Rubber as Binders on the Flexural and Water Absorption Properties of Recycled Paper Pulp Based Composites

    Directory of Open Access Journals (Sweden)

    Oladele Isiaka Oluwole

    2015-10-01

    Full Text Available Responsiveness was given to the effects of cassava starch and natural rubber as binders on the flexural strength and the water absorptivity properties of the developed rattan particulate reinforced paper pulp based composites. Paper pulp was produced by chopping waste papers into smaller pieces and soaked in boiled water after which it was stirred thoroughly to form paper pulp. Rattan particulate was produced by hammering, chopping, pounding and milling of rattan canes followed by sieving into a particle size of 437 µ. Varying mass of paper from 300-400 g and particulate rattan in treated and untreated form of 2-8 g were mixed and bonded with natural rubber and cassava starch, respectively for the various samples developed. The mixtures were thoroughly mixed to produce homogenous pastes and poured into 150 x 50 x 30 mm detachable mould and compacted for 5 minutes using a laboratory compaction machine maintained at 20 KN. The developed composites were allowed to cure at room temperature for 27 days after which flexural and water absorptivity tests were carried out on the samples. It was noticed that the composite samples ST4 and S5 containing cassava starch happen to be the best in terms of flexural strength while NR2 gave the best water- repellent outcome.

  14. Enhanced isopropanol and n-butanol production by supplying exogenous acetic acid via co-culturing two clostridium strains from cassava bagasse hydrolysate.

    Science.gov (United States)

    Zhang, Shaozhi; Qu, Chunyun; Huang, Xiaoyan; Suo, Yukai; Liao, Zhengping; Wang, Jufang

    2016-07-01

    The focus of this study was to produce isopropanol and butanol (IB) from dilute sulfuric acid treated cassava bagasse hydrolysate (SACBH), and improve IB production by co-culturing Clostridium beijerinckii (C. beijerinckii) with Clostridium tyrobutyricum (C. tyrobutyricum) in an immobilized-cell fermentation system. Concentrated SACBH could be converted to solvents efficiently by immobilized pure culture of C. beijerinckii. Considerable solvent concentrations of 6.19 g/L isopropanol and 12.32 g/L butanol were obtained from batch fermentation, and the total solvent yield and volumetric productivity were 0.42 g/g and 0.30 g/L/h, respectively. Furthermore, the concentrations of isopropanol and butanol increased to 7.63 and 13.26 g/L, respectively, under the immobilized co-culture conditions when concentrated SACBH was used as the carbon source. The concentrations of isopropanol and butanol from the immobilized co-culture fermentation were, respectively, 42.62 and 25.45 % higher than the production resulting from pure culture fermentation. The total solvent yield and volumetric productivity increased to 0.51 g/g and 0.44 g/L/h when co-culture conditions were utilized. Our results indicated that SACBH could be used as an economically favorable carbon source or substrate for IB production using immobilized fermentation. Additionally, IB production could be significantly improved by co-culture immobilization, which provides extracellular acetic acid to C. beijerinckii from C. tyrobutyricum. This study provided a technically feasible and cost-efficient way for IB production using cassava bagasse, which may be suitable for industrial solvent production. PMID:27116556

  15. Effect of addition of different hydrocolloids on pasting, thermal, and rheological properties of cassava starch

    OpenAIRE

    Tatiana Dias Leite; Joel Fernando Nicoleti; Ana Lúcia Barretto Penna; Célia Maria Landi Franco

    2012-01-01

    Starches and gums are hydrocolloids frequently used in food systems to provide proper texture, moisture, and water mobility. Starch-gum interaction in food systems can change the starch granule swelling and its gelatinization and rheological properties. In this study, the effect of the addition of xanthan gum (XG), sodium carboxymethyl cellulose (SCMC), and carrageenan (CAR) at the concentrations of the 0.15, 0.25, 0.35 and 0.45% (w/v) on the pasting, thermal, and rheological properties of ca...

  16. 水解酶法回收木薯黄浆废水中的淀粉%Study on recovery of starch from cassava starch wastewater using aqueous enzymatic method

    Institute of Scientific and Technical Information of China (English)

    崔雯; 莫创荣; 李小明; 安鸿雪; 孙文博; 刘侃; 邓国龙

    2013-01-01

    以胰蛋白酶作为水解酶,采用水酶法从木薯黄浆废水中回收淀粉.通过调节酶加量、温度、时间、pH等因素,得到木薯淀粉的最佳回收条件:加酶量0.05 g/L,酶解时间3h,酶解温度35℃,酶解pH值为8.5.在最佳条件下得到沉淀物质量为10.85 g/L,沉淀物中淀粉含量为80.4 g/100 g,粗淀粉质量为8.72 g/L.%The aqueous enzymatic method was used to recovery of starch from cassava starch wastewater by using trypsin as hydrolase.The factors based on the enzyme dosage,temperature,time and pH.The best recovery conditions of cassava starch were as follows:the amount of enzyme 0.05 g/L,hydrolysis time 3 h,enzymolysis temperature 35 ℃,enzyme solution pH value 8.5.Under the optimum conditions obtained sediment quality of 10.85 g/L,starch content of sediment was 80.4 g/100 g,crude starch quality of 8.72 g/L.

  17. 木薯采后生理性变质与淀粉特性研究%Physiological Deterioration and Starch Characteristics of Harvest Cassava Tuberous Root

    Institute of Scientific and Technical Information of China (English)

    姚庆群; 张振文

    2012-01-01

    The rapid physiological deterioration (PD) of cassava tuberous root is main constraint factor that limits the development of cassava industry. In order to know the relationship between PD and starch characteristics on cassava, there are five varieties subjected ( SC205, SC5, SC6, SC8 and SC10) on four indices, including dry matter, starch content, amylopectin content and starch clarity. The result showed that the indices of starch characteristics were decreased by PD in all subjects, and the decline of SC205 was appeared earlier than others. The correlation analysis were indicated that Positive correlation and significant positive correlation between amylopectin content and starch content, amylopectin content respectively. Thus, we can see starch clarity was affected by the PD during storage, and starch quality of cassava tuberous root was also cut down greatly.%以华南系列的SC205、SC5、SC6、SC8和SCIO五个木薯品种为材料,于采收后不同时间分析其块根生理变质程度、干物质含量、淀粉含量、支链淀粉比例和淀粉透明度等指标,探讨木薯生理变质与块根淀粉特性的关系。研究结果表明:采后生理变质对块根淀粉特性有明显影响,所有品种淀粉特性指标在采后均呈下降趋势,其中下降最快的是SC205。对各指标的相关分析表明,支链淀粉分别与淀粉含量和淀粉透明度呈显著正相关和极显著正相关。可见,生理变质可导致淀粉透明度的下降,影响淀粉的商品品质。

  18. Conversion of cassava starch to biomass, carbohydrates, and acids by Aspergillus niger.

    Science.gov (United States)

    Tan, K H; Ferguson, L B; Carlton, C

    1984-01-01

    The filamentous fungus, Aspergillus niger, efficiently converted cassava polysaccharides to mycelial mass, simple sugars, and acids during the course of its growth. A typical 70-ml culture broth containing 2% cassava polysaccharides yielded 0.38 g dry mycelial mass, 1.14 mmol reducing sugars, and 1.17 meq acids at the end of 42 h. About 70% of the initial total carbohydrate in the medium was degraded during the same period. The sugars and acids in the culture broths were analyzed by HPLC on a single Aminex HPX-87 column at 55 degrees C, using 0.013 N H2SO4 as the eluting solvent. Cassava polysaccharides were degraded to oligosaccharides, maltotriose, maltose, and glucose beyond the 20-h growth periods, with maltotriose emerging as the major simple sugar. The appearance of citric, malic, gluconic, succinic, and fumaric acids accounted mostly for the decreasing pH in the growth media. Formation of carbohydrate species in the culture broths was closely related to the biosynthesis and secretion of several carbohydrases by A. niger. The extracellular carbohydrases were separated and identified by chromatofocusing and polyacrylamide gel electrophoresis to be amyloglucosidase (EC 3.1.2.3), alpha-amylase (EC 3.2.1.1), and alpha-glucosidase (EC 3.2.1.20), respectively.

  19. Physical characteristics of extruded cassava starch Características físicas de amido de mandioca extrusado

    Directory of Open Access Journals (Sweden)

    Magali Leonel

    2009-08-01

    Full Text Available Considering the importance of cassava starch for Brazilian industries, the current work aimed at evaluating the effects of extrusion parameters on the physical characteristics, mainly viscosity properties of extruded cassava starch. A factorial central composite design (2³ with three independent variables and the response surface methodology were used to evaluate the results of expansion index, specific volume, water absorption index, water solubility index, color and paste properties, according to the variations in the moisture content, barrel temperature and screw speed. Results indicated that barrel temperature influenced the expansion index, specific volume, water absorption index, all the color parameters, the initial viscosity, peak and final viscosity. Feed moisture influenced the specific volume, color parameters, final viscosity and retrogradation. The screw speed had effects on water absorption index, color components as well as on the final viscosity and retrogradation of extruded starch. High moisture, low screw speed and intermediate temperature provided lower starch degradation, which is desirable for pre-cooked starch.Considerando a importância do amido de mandioca para as indústrias brasileiras, este trabalho teve por objetivo avaliar os efeitos de parâmetros de extrusão sobre as características físicas e propriedades de pasta do amido de mandioca extrusado. Foi utilizado o delineamento fatorial do tipo central composto rotacional com três variáveis independentes (2³ e a metodologia de superfície de resposta para avaliar os resultados de índice de expansão, volume específico, índice de absorção de água, índice de solubilidade em água, cor e propriedades de pasta, de acordo com as variações de umidade, temperatura de extrusão e rotação da rosca. A temperatura de extrusão influenciou o índice de expansão, volume específico, índice de absorção de água, todos os parâmetros de cor e a viscosidade

  20. Production and characterization of thermoplastic cassava starch, functionalized poly(lactic acid), and their reactive compatibilized blends

    Science.gov (United States)

    Detyothin, Sukeewan

    Cassava starch was blended with glycerol using a co-rotating twin-screw extruder (TSE). Thermoplastic cassava starch (TPCS) at a ratio of 70/30 by weight of cassava/glycerol was selected and further blended with other polymers. TPCS sheets made from compression molding had low tensile strength (0.45 +/- 0.05 MPa) and Young's modulus (1.24 +/- 0.58 MPa), but moderate elongation at break (83.0 +/- 0.18.6%), medium level of oxygen permeability, and high water vapor permeability with a very high rate of water absorption. TPCS was blended with poly(lactic acid) (PLA) at various ratios by using a TSE. The blend resins exhibited good properties such as increased thermal stability (Tmax) and crystallinity of PLA, and improved water sensitivity and processability of TPCS. PLA and TPCS exhibited a high interfacial tension between the two phases of 7.9 mJ·m -2, indicating the formation of an incompatible, immiscible blend. SEM micrographs showed a non-homogeneous distribution of TPCS droplets in the PLA continuous phase. TEM micrographs of the blend films made by cast-film extrusion showed coalescence of the TPCS droplets in the PLA continuous phase of the blend, indicating that the compatibility between the polymer pair needs to be improved. A response surface methodology (RSM) design was used to analyze the effects of maleic anhydride (MA) and 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (Luperox or L101) contents, and TSE screw speed on the degree of grafted MA and number average molecular weight (Mn) of functionalized PLA (PLA-g-MA), a reactive compatibilizer. PLA-g- MA made by reactive extrusion had an array of colors depending on the content of L101 and MA used. New FTIR peaks suggested that MA was grafted onto the PLA backbone and oligomeric MA may occur. Increasing L101 increased the degree of grafting and decreased Mn, but the Mn of the PLA-g-MA's produced with a high amount of L101 was stable during storage. MA exhibited an optimum concentration for maximizing the

  1. Improvement of D-Ribose Production from Corn Starch Hydrolysate by a Transketolase-Deficient Strain Bacillus subtilis UJS0717

    Directory of Open Access Journals (Sweden)

    Zhuan Wei

    2015-01-01

    Full Text Available D-Ribose is a five-carbon sugar and generally used as an energy source to improve athletic performance and the ability. The culture conditions for maximum D-ribose production performance from cheap raw material corn starch hydrolysate were improved by using one-factor-at-a-time experiments and a three-level Box-Behnken factorial design. The optimal fermentation parameters were obtained as 36°C culture temperature, 10% inoculum volume, and 7.0 initial pH. The mathematical model was then developed to show the effect of each medium composition and their interactions on the production of D-ribose and estimated that the optimized D-ribose production performance with the concentration of 62.13 g/L, yield of 0.40 g/g, and volumetric productivity of 0.86 g/L·h could be obtained when the medium compositions were set as 157 g/L glucose, 21 g/L corn steep liquor, 3.2 g/L (NH42SO4, 1 g/L yeast extract, 0.05 g/L MnSO4·H2O, and 20 g/L CaCO3. These findings indicated the D-ribose production performance was significantly improved compared to that under original conditions.

  2. Properties and antioxidant action of actives cassava starch films incorporated with green tea and palm oil extracts.

    Directory of Open Access Journals (Sweden)

    Kátya Karine Nery Carneiro Lins Perazzo

    Full Text Available There is an interest in the development of an antioxidant packaging fully biodegradable to increase the shelf life of food products. An active film from cassava starch bio-based, incorporated with aqueous green tea extract and oil palm colorant was developed packaging. The effects of additives on the film properties were determined by measuring mechanical, barrier and thermal properties using a response surface methodology design experiment. The bio-based films were used to pack butter (maintained for 45 days under accelerated oxidation conditions. The antioxidant action of the active films was evaluated by analyzing the peroxide index, total carotenoids, and total polyphenol. The same analysis also evaluated unpacked butter, packed in films without additives and butter packed in LDPE films, as controls. The results suggested that incorporation of the antioxidants extracts tensile strength and water vapor barrier properties (15 times lower compared to control without additives. A lower peroxide index (231.57%, which was significantly different from that of the control (p<0.05, was detected in products packed in film formulations containing average concentration of green tea extracts and high concentration of colorant. However, it was found that the high content of polyphenols in green tea extract can be acted as a pro-oxidant agent, which suggests that the use of high concentration should be avoided as additives for films. These results support the applicability of a green tea extract and oil palm carotenoics colorant in starch films totally biodegradable and the use of these materials in active packaging of the fatty products.

  3. Kinetic modeling of native Cassava starch thermo-oxidative degradation using Weibull and Weibull-derived models.

    Science.gov (United States)

    Janković, Bojan

    2014-01-01

    A new approach in kinetic modeling of thermo-oxidative degradation process of starch granules extracted from the Cassava roots was developed. Based on the thermoanalytical measurements, three reaction stages were detected. Using Weibull and Weibull-derived (inverse) models, it was found that the first two reaction stages could be described with the change of apparent activation energy (Ea) on conversion fraction (α(T)) (using "Model-free" analysis). It was found that first reaction stage, which involves dehydration and evaporation of lower molecular mass fractions, can be described with an inverse Weibull model. This model with its distribution of Ea values and derived distribution parameters includes the occurrence of three-dimensional diffusion mechanism. The second reaction stage is very complex, and it was found to contain the system of simultaneous reactions (where depolymerization occurs), and can be described with standard Weibull model. Identified statistical model with its distribution of Ea values and derived distribution parameters includes the kinetic model that gives the variable reaction order values. Based on the established models, shelf-life studies for first two stages were carried out. Shelf-life testing has shown that optimal dehydration time is achieved by a programmed heating at medium heating rate, whereas optimal time of degradation is achieved at highest heating rate.

  4. Synthesis, characterization and in vitro drug release of cisplatin loaded Cassava starch acetate–PEG/gelatin nanocomposites

    Directory of Open Access Journals (Sweden)

    V. Raj

    2016-10-01

    Full Text Available The aim of the present study is to examine the feasibility of Cassava starch acetate (CSA–polyethylene glycol (PEG–gelatin (G nanocomposites as controlled drug delivery systems. It is one of the novel drug vehicles which can be used for the controlled release of an anticancer drug. Simple nano precipitation method was used to prepare the carriers CSA–PEG–G nanocomposites and they were used for entrapping cisplatin (CDDP. Through FT-IR spectroscopy, the linking among various components of the system was proved and with the help of scanning electron microscope and transmission electron microscopy (TEM, the surface morphology was investigated. The particle sizes of the CSA–CDDP, CSA–CDDP–PEG and CSA–CDDP–PEG–G polymer composites were between 140 and 350 nm, as determined by a Zetasizer. Drug encapsulation efficiency, drug loading capacity and in vitro release of CDDP were evaluated respectively. The findings revealed that the cross linked CSA–PEG–G nanocomposites can be a potential polymeric carrier for controlled delivery of CDDP.

  5. Effect of sugar addition on glass transition temperatures of cassava starch with low to intermediate moisture contents.

    Science.gov (United States)

    Figueroa, Yetzury; Guevara, Marvilan; Pérez, Adriana; Cova, Aura; Sandoval, Aleida J; Müller, Alejandro J

    2016-08-01

    This work studies how sucrose (S) addition modifies the thermal properties of cassava starch (CS). Neat CS and CS-S blends with 4, 6 and 8% sugar contents (CS-S-4%, CS-S-6% and CS-S-8%) were prepared and analyzed by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA), in a wide range of moisture levels (2-20%). In equilibrated samples with moisture contents lower than 10%, twoendothermic steps were observed during first DSC heating scans and two corresponding relaxation maxima in tan δ were detected by DMTA. The first transition, detected at around 45-55°C by both DSC and DMTA, is frequently found in starchy foods, while the second observed at higher temperatures is associated to the glass transition temperature of the blends. At higher moisture contents, only one thermal transition was observed. Samples analyzed immediately after cooling from the melt (i.e., after erasing their thermal history), exhibited a single glass transition temperature, regardless of their moisture content. Addition of sugar promotes water plasticization of CS only at high moisture contents. In the low moisture content range, anti-plasticization was observed for both neat and sugar-added CS samples. Addition of sugar decreases the moisture content needed to achieve the maximum value of the glass transition temperature before plasticization starts. The results of this work may be valuable for the study of texture establishment in low moisture content extruded food products. PMID:27112870

  6. Induced mutation breeding as a tool for the genetic improvement of cassava landraces for high starch and delayed post harvest deterioration (PPD) in Ghana

    International Nuclear Information System (INIS)

    Cassava a major staple in Ghana that contributes 22% of Agricultural Gross Domestic Product provides high and reliable cheap source of carbohydrates for over 200 million people has assumed an industrial and cash crop status in Sub- Sahara Africa. However, cassava suffers from pest and diseases, with the starchy roots rapidly deteriorating within 24 to 72 hours after harvest resulting in close to 20% loss in the fresh roots. Cassava crosses for the introgression of useful genes for delayed Post harvest Deterioration where Molecular Markers Assisted selected (MAS) inter-specific hybrids with delayed PPD properties were crossed with preferred land races. Inter-specific hybrids of walkererea evaluated showed remarkable disease resistance in all ecological zones tested, PPD score Clone CR 52A-25 additionally showed no signs of post harvest physiological deterioration after the seventh day of harvest and AR 14-10 had unique starch properties for potential industrial use. Induced mutation of tissue culture plantlets of four preferred cassava landraces 'Cedi bankye', 'Sisipe 166', 'Debor' (ancient variety) and 'Dabodabo' (zigzag plant architecture with stay green properties) at two levels of doses 15Gy and 12 Gy were at V5 stage hardened and established in a replicated field trial in three locations. Initial results showed high root yields for doses of 12Gy and remarkable resistance for ACMD (1.5 score) for all mutants at 3MAP, Debor at both doses showed the best vigour for all locations. Induced mutation of botanical seeds from landraces and inter-specific hybrids of walkererea at 200 and 300Gy showed moderate disease reaction and plant vigor. The mutants would be tested alongside the control for starch and PPD at 9MAP and 12MAP. (author)

  7. PROCESSAMENTO INDUSTRIAL DE FÉCULA DE MANDIOCA E BATATA DOCE - UM ESTUDO DE CASO INDUSTRIAL PROCESSING OF CASSAVA AND SWEET POTATO STARCH - CASE STUDY

    Directory of Open Access Journals (Sweden)

    M. LEONEL

    1998-08-01

    Full Text Available A indústria de amido vem crescendo e se aperfeiçoando nos últimos anos, levando à necessidade de produtos com características específicas que atendam as exigências do mercado, o que possibilita o processamento de matérias-primas amiláceas ainda pouco exploradas. O trabalho teve como objetivo analisar o processamento industrial de fécula de mandioca e batata doce. Através da análise da composição da raiz, fécula e bagaço, bem como do balanço de massa dos processos, objetivou-se estabelecer a eficiência de uma planta industrial de processamento de mandioca, para a obtenção de fécula de batata doce. Os resultados demonstraram que a fécula de batata doce obtida está dentro dos limites da legislação brasileira e que parte do amido não foi extraído no processamento, sendo gerado um bagaço com 79,94 % de amido e com composição semelhante ao gerado no processamento de mandioca que contém em média 80 % de amido. A comparação dos balanços de massa demonstrou uma menor eficiência da planta no processamento da batata doce (18,3% de rendimento, quando comparado com o de mandioca (25,5% de rendimento com umidade de 13,75 % e 12,3 %, respectivamente, na fécula. A retenção de amido no bagaço indicou deficiência no processo industrial de extração independentemente da matéria-prima.Starch industries have great interest by new starch raw material. This work compared the industrial manufacture yield of cassava and sweet potato starch in a Brazilian company. The results showed that the commercial starch of sweet potato was in quality specification of Brazilian legislation. The solid fibrous residue generated during the processing contained 79,94 % starch and similar composition of the cassava residue. The industrial yield was higher in cassava processing (25% than sweet potato (18,3%. The starch retention in the solid waste indicated an inefficient extraction process for two raw materials.

  8. 湿热处理对木薯淀粉结构和性质的影响%Effect of heat-moisture treatment on structure and properties of cassava starch

    Institute of Scientific and Technical Information of China (English)

    汪树生; 杨秋实; 苏玉春; 陈光

    2013-01-01

    对木薯淀粉进行湿热处理,研究了不同初始含水量对木薯淀粉结构和性质的影响.实验结果表明:经湿热处理后的木薯淀粉颗粒表面出现凹坑,随着初始含水量增加,淀粉颗粒表面凹坑的数量增加,同时黏结现象变得严重;湿热处理木薯淀粉的糊化温度随着初始含水量的增加而升高;经湿热处理后,木薯淀粉对酸和酶的敏感性增加,更容易被酸和酶水解.%Cassava starch was heat-moisture treated and the effects of initial moisture on the structure and properties of heat-moisture treated cassava starch were studied. The results indicated that there were dents on the surface of starch granule, the number of dents increased alone with the ascent of initial moisture of heat-moisture treated cassava starch, while the bonding of starch granule became serious. The gelatinization temperature of heat-moisture treated cassava starch increased with the higher of initial moisture. The cassava starch became sensitive to acid or enzyme hydrolysis after heat-moisture treatment, easier to be hydrolyzed by acid or enzyme.

  9. Effect of cassava starch coating on quality and shelf life of fresh-cut pineapple (Ananas comosus L. Merril cv "Pérola").

    Science.gov (United States)

    Bierhals, Vânia S; Chiumarelli, Marcela; Hubinger, Miriam D

    2011-01-01

    This research studied the influence of treatment with ascorbic acid, citric acid, and calcium lactate dipping and cassava starch edible coatings on quality parameters and shelf life of fresh-cut pineapple in slices during 12 d at 5 °C. After previous tests, the treatments selected for this study were samples dipped into antibrowning solution with 0.5% of ascorbic acid and 1% of citric acid, with and without 2% of calcium lactate and coated with 2% of cassava starch suspensions. Changes in weight loss, juice leakage, mechanical properties (stress at failure), color parameters (L* and H*), ascorbic acid content, sensory acceptance, and microbial growth of fruits were evaluated. Samples only treated with antibrowning agents were used as control. Edible coatings with and without calcium lactate were efficient in reducing weight loss, juice leakage, and maintaining firmness during storage. However, these samples showed more browning and the ascorbic acid content was reduced. All treatments presented good sensory acceptance (scores above 6). The determining factor of shelf life of pineapple slices was the microbial spoilage. A shelf life of 8 d was obtained for pineapple slices only treated with antibrowning agents. On the other hand, coated samples showed a reduced shelf life of 7 d and higher yeast and mold growth. Thus, although cassava starch coatings were efficient in reducing respiration rate, weight loss, and juice leakage and maintained mechanical properties, these treatments were not able to increase the shelf life of minimally processed pineapple. Practical Application: Pineapple fruit is highly appreciated for its aroma, flavor, and juiciness, but its immediate consumption is difficult. Therefore, pineapple is a potential fruit for minimal processing. However, shelf life of fresh-cut pineapple is very limited by changes in color, texture, appearance, off-flavors, and microbial growth. The use of edible coatings as gas and water vapor barrier and antibrowning

  10. Field testing and exploitation of genetically modified cassava with low-amylose or amylose-free starch in Indonesia

    OpenAIRE

    Koehorst-van Putten, H. J. J.; Sudarmonowati, E.; Herman, M; Pereira-Bertram, I. J.; Wolters, A. M. A.; Meima, H.; Vetten, de, N.; Raemakers, C.J.J.M.; Visser, R. G. F.

    2012-01-01

    The development and testing in the field of genetically modified -so called- orphan crops like cassava in tropical countries is still in its infancy, despite the fact that cassava is not only used for food and feed but is also an important industrial crop. As traditional breeding of cassava is difficult (allodiploid, vegetatively propagated, outbreeding species) it is an ideal crop for improvement through genetic modification. We here report on the results of production and field testing of g...

  11. Effect of acid additives on graft copolymerization and water absorption of graft copolymers of cassava starch and acrylamide/acrylic acid

    International Nuclear Information System (INIS)

    Gelatinized cassava starch was radiation graft copolymerized with acrylamide or acrylic acid in the presence of sulfuric acid, nitric acid or maleic acid at a specific dose rate to a fixed total dose. Homopolymer or free copolymer was extracted by water to obtain the pure graft copolymer, which was subsequently saponified with 5% potassium hydroxide solution at room temperature for 90 min. The saponified graft copolymer was investigated for the effect of acid additives and water absorption. The addition of 2% maleic acid into the grafting reaction containing acrylamide-to-starch ratio of 2.5:1 can produce the superabsorbent copolymer having water absorption as high as 2,256 ± 25 g g-1. The effect of acid additive was explained. (author)

  12. Morphological and mechanical properties of thermoplastic starch (TPS) and its blend with poly(lactic acid)(PLA) using cassava bagasse and starch; Caracterizacao morfologica e mecanica de amidos termoplasticos (TPS) e suas blendas com poliacido latico (PLA) utilizando bagasso e amido de mandioca

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Eliangela de M.; Correa, Ana C.; Campos, Adriana de; Marconcini, Jose M.; Mattoso, Luiz H.C. [Embrapa Instrumentacao Agropecuaria-CNPdia, Laboratorio Nacional de Nanotecnologia para o Agronegocio - LNNA, Sao Carlos, SP (Brazil); Curvelo, Antonio A.S. [Universidade de Sao Paulo-USP, Instituto de Quimica da USP de Sao Carlos, SP (Brazil)

    2011-07-01

    This study aims the use of an agro waste coming from the industrialization of cassava starch, known as cassava bagasse (BG). This material contains residual starch and cellulose fibers which can be used to obtain thermoplastic starch (TPS) and /or blends reinforced with fibers. In this context, it was prepared a thermoplastic starch with BG (TPSBG) and evaluated the incorporation of 20wt% of it into the biodegradable polymer poly (lactic acid) (PLA), resulting in a blend PLA/TPSBG20. The materials were investigated through morphology (scanning electron microscopy with field emission gun (FEG), x-ray diffraction (XRD), and mechanical behavior (tensile test). Their properties were compared to the blend PLA/TPSI20 in which TPSI is obtained from commercial cassava starch. The results showed that the use of bagasse generates homogenous materials with higher mechanical strength if compared to TPS obtained from commercial cassava starch. The fiber in this residue acted as reinforcement for TPS and PLA/TPS systems. (author)

  13. Effects of crosslinking temperature and time on microstructure and stability of cassava starch microspheres.

    Science.gov (United States)

    Puncha-Arnon, Santhanee; Jiranuntakul, Wittawat; Uttapap, Dudsadee

    2015-12-10

    Starch microspheres (SMs) were prepared by a water-in-water emulsion-crosslinking technique at 4 °C and 30 °C for 1, 6, 12 and 24h; the SMs obtained were analyzed for crosslinking density, morphology, crystalline structure, and stability against temperature, pH, and α-amylase hydrolysis. The crosslinking degree at 30 °C was considerably higher than that at 4 °C. SMs prepared at 4 °C for less than 12h incubation had larger size and more porous structure as compared with those prepared at 30 °C, but the morphology became comparable (spherical shape with smooth surface and dense structure) after 24h incubation. All SMs samples displayed amorphous structure. Stability tests revealed that the SMs were very stable under acidic and mild basic pH; however, stability against α-amylase hydrolysis varied depending on incubation temperature and time.

  14. Bi-Functional Biobased Packing of the Cassava Starch, Glycerol, Licuri Nanocellulose and Red Propolis

    Science.gov (United States)

    Costa, Samantha Serra; Druzian, Janice Izabel; Machado, Bruna Aparecida Souza; de Souza, Carolina Oliveira; Guimarães, Alaíse Gil

    2014-01-01

    The aim of this study was to characterize and determine the bi-functional efficacy of active packaging films produced with starch (4%) and glycerol (1.0%), reinforced with cellulose nanocrystals (0–1%) and activated with alcoholic extracts of red propolis (0.4 to 1.0%). The cellulose nanocrystals used in this study were extracted from licuri leaves. The films were characterized using moisture, water-activity analyses and water vapor-permeability tests and were tested regarding their total phenolic compounds and mechanical properties. The antimicrobial and antioxidant efficacy of the films were evaluated by monitoring the use of the active films for packaging cheese curds and butter, respectively. The cellulose nanocrystals increased the mechanical strength of the films and reduced the water permeability and water activity. The active film had an antimicrobial effect on coagulase-positive staphylococci in cheese curds and reduced the oxidation of butter during storage. PMID:25383783

  15. Bi-functional biobased packing of the cassava starch, glycerol, licuri nanocellulose and red propolis.

    Science.gov (United States)

    Costa, Samantha Serra; Druzian, Janice Izabel; Machado, Bruna Aparecida Souza; de Souza, Carolina Oliveira; Guimarães, Alaíse Gil

    2014-01-01

    The aim of this study was to characterize and determine the bi-functional efficacy of active packaging films produced with starch (4%) and glycerol (1.0%), reinforced with cellulose nanocrystals (0-1%) and activated with alcoholic extracts of red propolis (0.4 to 1.0%). The cellulose nanocrystals used in this study were extracted from licuri leaves. The films were characterized using moisture, water-activity analyses and water vapor-permeability tests and were tested regarding their total phenolic compounds and mechanical properties. The antimicrobial and antioxidant efficacy of the films were evaluated by monitoring the use of the active films for packaging cheese curds and butter, respectively. The cellulose nanocrystals increased the mechanical strength of the films and reduced the water permeability and water activity. The active film had an antimicrobial effect on coagulase-positive staphylococci in cheese curds and reduced the oxidation of butter during storage.

  16. Bi-functional biobased packing of the cassava starch, glycerol, licuri nanocellulose and red propolis.

    Directory of Open Access Journals (Sweden)

    Samantha Serra Costa

    Full Text Available The aim of this study was to characterize and determine the bi-functional efficacy of active packaging films produced with starch (4% and glycerol (1.0%, reinforced with cellulose nanocrystals (0-1% and activated with alcoholic extracts of red propolis (0.4 to 1.0%. The cellulose nanocrystals used in this study were extracted from licuri leaves. The films were characterized using moisture, water-activity analyses and water vapor-permeability tests and were tested regarding their total phenolic compounds and mechanical properties. The antimicrobial and antioxidant efficacy of the films were evaluated by monitoring the use of the active films for packaging cheese curds and butter, respectively. The cellulose nanocrystals increased the mechanical strength of the films and reduced the water permeability and water activity. The active film had an antimicrobial effect on coagulase-positive staphylococci in cheese curds and reduced the oxidation of butter during storage.

  17. 皮状丝孢酵母B3利用木薯淀粉发酵生产微生物油脂%Microbial oil production by Trichosporon cutaneum B3 using cassava starch

    Institute of Scientific and Technical Information of China (English)

    袁锦云; 艾佐佐; 张志斌; 颜日明; 曾庆桂; 朱笃

    2011-01-01

    对皮状丝孢酵母B3以木薯淀粉水解液为碳源发酵生产微生物油脂培养条件进行了优化,并在2 L发酵罐中对茵体生长和油脂积累进行了考察.摇瓶实验表明,木薯淀粉水解液的浓度高于90g/L时不利于菌体的生长和油脂积累,皮状丝孢酵母B3发酵生产微生物油脂的最适氮源及其浓度、最适C/N比和pH分别为酵母提取物3.0g,L、116、6.0,在此条件下培养144h菌体生物量,油脂产量和油脂含量分别达到15.2g/L、6.22∥L和40.9%;在2 L发酵罐中分批发酵44 h后菌体生物量、油脂产量和油脂含量分别达28.7 g/L,12.27g/L和42.8%.以皮状丝孢酵母B3所产油脂制备生物柴油,其主要组成包括棕榈酸甲酯、硬脂酸甲酯、油酸甲酯、亚油酸甲酯等,且理化特性符合相关国家标准,可作为一种有潜力的化石燃料替代品.%Microbial oil, as raw material for biodiesel, can be produced by Trichosporon cutaneum B3 using cassava starch hydrolysate. Batch cultures demonstrated that there was little inhibitory effect with the concentration of cassava starch hydrolysate up to 90 g/L. The favorable initial pH, C/N molar ratio, nitrogen source and its concentration were 6.0, 116, yeast extract and 3.0 g/L, respectively. Under the optimized conditions, dry biomass reached 15.2 g/L and lipid content reached 40.9%after culture for 144 h in flask. Batch cultures in a 2 L stirred-tank fermenter were run for 44 h and resulted in dry biomass, lipid content and lipid yield of 28.7 g/L, 42.8% and 12.27 g/L, respectively. The chemical compositions of biodiesel prepared from lipids of T. cutaneum B3 mainly included palmitic acid methyl ester, stearic acid methyl ester, oleic acid methyl ester and linoleic acid methyl ester etc., and its main physicochemical properties were in compliance with relevant national diesel standards.Therefore, the biodiesel prepared from lipids of T. cutaneum B3 can serve as a potential fossil fuel alternatives.

  18. Synthesis and characterisation of simultaneous interpenetrating polymer networks (SIN formed by polystyrene and polyurethane obtained from castor oil and cassava starch polyol-suspensions

    Directory of Open Access Journals (Sweden)

    Juan Manuel Cabrera Anaya

    2011-01-01

    Full Text Available Castor oil was modified by transesterification with pentaerythritol and cassava starch was subsequently incorporated into this oil (oil modified by incorporating starch is called a polyol-suspension. Polyurethane/polystyrene SINs (simulta- neously produced IPNs were synthesised from them and styrene. Reactants used in the synthesis were MDI (methylene diphenyl diisocyanate as diisocyanate, DVB (divinylbenzene as crosslinking agent for polystyrene, dibutylamine as redox primer and benzoyl peroxide as styrene polymerisation primer. The variables considered in SIN synthesis were percentage weight ratio used in the modification (1.32%; 2.64% and 5.28% to increase polyol hydroxyl functionality, starch species incorporated into polyol (Brazilian, Venezuelan and commercial to vary the amount of amylopectin within the polyol-suspension, diisocyanate/hydroxyl NCO/OH (0.85 and 1 functional groups’ molar ratio and polyurethane/ polystyrene PU/PS weight ratio (70/30 and 80/20. A wide range of materials was obtained and characterised by tensile strength, hardness, chemical attack and Soxhlet extraction. The physical-mechanical properties of the materials produced with polyols (transesterified castor oil were improved when starch was incorporated into the polyol. Several tests indicated that 24 hours as curing time were not enough, because the SINs showed lower physical-mechanical properties than the homologous polyurethane elastomers did; thus, the curing time had to be increased to 48 hours.

  19. Cassava varietal screening for cooking quality: relationship between dry matter, starch content, mealiness and certain microscopic observations of the raw and cooked tuber

    International Nuclear Information System (INIS)

    Thirteen cassava (Manihot esculenta L Crantz) varieties from three successive annual harvests were screened for the mealiness of the cooked tuber, and the elasticity and smoothness of the pounded paste. Six were selected for further studies based on their mealiness and the starch and dry matter contents were determined. The diameter of the starch granules of the selected varieties and those of an irradiated M1V2 population were measured. Microscopic examinations of the raw and cooked cells of the irradiated M1V2 population were made. Correlations among all the parameters were studied. Varietal and seasonal differences in cooking quality were observed. There was no consistent relationship between mealiness of the boiled tuber and the elasticity and smoothness of the pounded paste. Varieties that were mealy were high in dry matter and starch content. The starch granules of mealy varieties were larger than those of nonmealy ones. There were no differences between mealy and non-mealy varieties in the arrangement of the cells or ‘cell condition’, of the raw tubers. However, the cells of the cooked tubers were held less cohesively, ie there was more ‘cell disorganisation’, in mealy varieties than in non-mealy ones

  20. Properties of cassava cross-linked carboxymethylated starch(Ⅰ)%木薯交联羧甲基淀粉的性质研究(Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    谭义秋; 黄祖强; 农克良

    2013-01-01

    采用搅拌球磨机对木薯淀粉进行机械活化,以活化60 min的木薯淀粉为原料,环氧氯丙烷为交联剂,一氯乙酸钠为醚化剂制备交联羧甲基淀粉,对交联羧甲基淀粉的溶解度,糊的透明度、冻融稳定性、抗老化、抗酸、抗剪切等性质进行研究.结果表明,相对于交联淀粉,交联羧甲基淀粉的溶解度增大、糊的透明度增大;相对于羧甲基淀粉,交联羧甲基淀粉的溶解度减小,糊的透明度降低;相对于交联淀粉和羧甲基淀粉,交联羧甲基淀粉糊的冻融稳定性、抗老化、抗酸和抗剪切能力增强.%The cross-linked carboxymethylated starch was prepared by cassava starch, mechanically activated for 60 min by a stirring-type ball mill, as a starting material, epichlorohydrin as cross-linked agent, and sodium chloroacetate as etherifying a-gent. The properties of the cross-linked carboxymethylated starch, such as solubility, transparency, freeze-thaw stability, anti-retrogradation ability, anti-acid ability and anti-shearing ability, were studied. The results showed that solubility and transparency of the cross-linked carboxymethylated starch increased compared to the cross-linked starch; solubility and transparency of the cross-linked carboxymethylated starch decreased compared to carboxymethylated starch; and the freeze-thaw stability, anti-retrogradation ability, anti-acid ability, and anti-shearing ability of the cross-linked carboxymethylated starch were enhanced compared to the cross-linked starch and carboxymethylated starch.

  1. Solid Substrate Fermentation of Cassava Peel for Poultry Feed Ingredient

    OpenAIRE

    Stephanie; Purwadaria T

    2013-01-01

    Cassava peel which is not used during cassava starch extraction is one of potential resources for animal feed. However, cassava peel has low level protein content, high level crude fiber, and high level of toxic cyanogenic compound. These problems limit the utilization of cassava peel as feed. Solid substrate fermentation using mold may be a solution process to increase its nutritional value and decrease toxic level of cassava peel. In this paper, matters that related with cassava peel fermen...

  2. Endophytic fungi from the Amazonian plant Paullinia cupana and from Olea europaea isolated using cassava as an alternative starch media source.

    Science.gov (United States)

    Sia, Eliandra de Freitas; Marcon, Joelma; Luvizotto, Danice Mazzer; Quecine, Maria Carolina; Tsui, Sarina; Pereira, José Odair; Pizzirani-Kleiner, Aline Aparecida; Azevedo, João Lúcio

    2013-01-01

    Endophytic fungi live inside plants, apparently do not cause any harm to their hosts and may play important roles in defense and growth promotion. Fungal growth is a routine practice at microbiological laboratories, and the Potato Dextrose Agar (PDA) is the most frequently used medium because it is a rich source of starch. However, the production of potatoes in some regions of the world can be costly. Aiming the development of a new medium source to tropical countries, in the present study, we used leaves from the guarana (a tropical plant from the Amazon region) and the olive (which grows in subtropical and temperate regions) to isolate endophytic fungi using PDA and Manihot Dextrose Agar (MDA). Cassava (Manihot esculenta) was evaluated as a substitute starch source. For guarana, the endophytic incidence (EI) was 90% and 98% on PDA and MDA media, respectively, and 65% and 70% for olive, respectively. The fungal isolates were sequenced using the ITS- rDNA region. The fungal identification demonstrated that the isolates varied according to the host plant and media source. In the guarana plant, 13 fungal genera were found using MDA and six were found using PDA. In the olive plant, six genera were obtained using PDA and 4 were obtained using MDA. The multivariate analysis results demonstrated the highest fungal diversity from guarana when using MDA medium. Interestingly, some genera were isolated from one specific host or in one specific media, suggesting the importance of these two factors in fungal isolation specificity. Thus, this study indicated that cassava is a feasible starch source that could serve as a potential alternative medium to potato medium. PMID:25674409

  3. Endophytic fungi from the Amazonian plant Paullinia cupana and from Olea europaea isolated using cassava as an alternative starch media source.

    Science.gov (United States)

    Sia, Eliandra de Freitas; Marcon, Joelma; Luvizotto, Danice Mazzer; Quecine, Maria Carolina; Tsui, Sarina; Pereira, José Odair; Pizzirani-Kleiner, Aline Aparecida; Azevedo, João Lúcio

    2013-01-01

    Endophytic fungi live inside plants, apparently do not cause any harm to their hosts and may play important roles in defense and growth promotion. Fungal growth is a routine practice at microbiological laboratories, and the Potato Dextrose Agar (PDA) is the most frequently used medium because it is a rich source of starch. However, the production of potatoes in some regions of the world can be costly. Aiming the development of a new medium source to tropical countries, in the present study, we used leaves from the guarana (a tropical plant from the Amazon region) and the olive (which grows in subtropical and temperate regions) to isolate endophytic fungi using PDA and Manihot Dextrose Agar (MDA). Cassava (Manihot esculenta) was evaluated as a substitute starch source. For guarana, the endophytic incidence (EI) was 90% and 98% on PDA and MDA media, respectively, and 65% and 70% for olive, respectively. The fungal isolates were sequenced using the ITS- rDNA region. The fungal identification demonstrated that the isolates varied according to the host plant and media source. In the guarana plant, 13 fungal genera were found using MDA and six were found using PDA. In the olive plant, six genera were obtained using PDA and 4 were obtained using MDA. The multivariate analysis results demonstrated the highest fungal diversity from guarana when using MDA medium. Interestingly, some genera were isolated from one specific host or in one specific media, suggesting the importance of these two factors in fungal isolation specificity. Thus, this study indicated that cassava is a feasible starch source that could serve as a potential alternative medium to potato medium.

  4. Studies on Photosynthetic Characteristics of High and Low Starch Cassava Variety%高低淀粉木薯品种光合特性研究

    Institute of Scientific and Technical Information of China (English)

    唐娟娟; 罗兴录; 韦素; 蒋冬兰

    2012-01-01

    The photosynthetic characteristics of high and low starch cassava variety were studied with LI-6400 portable photosynthesis-fluorescence measurement instrument in this experiment. The results showed that, in the whole growth period, the high and low cassava starch varieties net photosynthetic rate rise was first after a downward trend. In seedling stage of cassava, 'Fuxuan0l' solar net photosynthetic rate was significantly lower than SC124. In the root of swollen, 'Fuxuan0l' of solar net photosynthetic rate was significantly higher than SCI24. In root formation, root at maturity, no obvious difference. In the whole growth period, the high and low cassava starch varieties transpiration rate rise was first after a downward trend. Cassava in seedling stage, the root formation, root at maturity, the transpiration rate of 'Fuxuan0l' was obviously lower than SCI24. And in the root of swollen, 'Fuxuan0l' the transpiration rate was higher than SC124, but no obvious difference. In the whole growth period, the high and low cassava starch varieties stomatal conductance was first after the rise of the decline of the trend. In the whole growth period of cassava, 'Fuxuan0l' solar stomatal conductance were lower than SC124. In the whole growth period, the high and low cassava starch varieties intercellular CO2 concentration was first falling trend after rising. In seedling stage, the formation of the root of cassava, 'Fuxuan0l' solar intercellular CO2 concentration was lower than SC124, but no obvious difference. In the root of swollen, 'Fuxuan0l' solar intercellular CO2 concentration was significantly higher than SC124. In root at maturity, 'Fuxuan0l' solar intercellular CO2 concentration was significantly lower than SC124.%为了探讨高低淀粉木薯品种不同生育期内光合特性的变化,以SC124和‘辐选01’两个块根淀粉含量不同的木薯品种为材料,利用LI-6400光合作用测定仪,研究高、低淀粉木薯品种的光合特性.结果表明:在

  5. 交联木薯淀粉微球的合成与表征%Synthesis and characterization of crosslinked cassava starch microspheres

    Institute of Scientific and Technical Information of China (English)

    乔支卫; 汤建萍; 丁立稳

    2011-01-01

    Crosslinked cassava starch microspheres (CCSM) were prepared by crosslinking of cassava starch and N, N'-methylene-bis-acrylamide(MBA) in inverse suspension. The polymer was characterizated by scanning electron microscopy (SEM), Fourier transform infrared spec-troscopy (FTIR) and X-ray diffractometer (XRD). The technique of polymerization was studied, and the statics adsorption behavior of CCSM to Fe3+ was investigated. The photo of SEM indicated that the CCSM are sherical particulates with rough surface and small particle diameter. The optimum polymerization conditions were decided by experiments as follows: 2.4 g of cassava starch,0.5 g of MBA,0.6 g of K2S2O8,1: 4 of the water-oil phase volume ratio,polymerization temperature at 65℃ and polymerization time for 2 h. The adsorption results showed that the CCSM have good adsorption property to Fe3+ .%以木薯淀粉为原料,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,通过逆向悬浮聚合法合成交联木薯淀粉微球(CCSM).利用扫描电镜、傅里叶变换红外光谱、X射线粉末衍射对聚合物的结构进行了表征.同时实验考察了聚合反应工艺条件,研究了交联木薯淀粉微球对Fe3+的静态吸附行为.扫描电镜照片显示合成的交联木薯淀粉微球呈圆球形,表面粗糙,粒径小.实验确定了适宜的聚合工艺条件为木薯淀粉用量2.4 g、交联剂MBA用量0.5 g、引发剂K2S2O8用量0.6 g、水油相体积比1:4、聚合温度65℃、聚合时间2 h.吸附实验结果显示交联木薯淀粉微球对Fe3+有很好的吸附性能.

  6. Uso de fécula de mandioca na pó-colheita de manga 'surpresa' Use of cassava starch in the 'surpresa' mango postharvest

    Directory of Open Access Journals (Sweden)

    Laerte Scanavaca Júnior

    2007-04-01

    Full Text Available A manga é uma fruta tropical climatéria que amadurece rapidamente depois de colhida. Avaliou-se a vida útil pós-colheita de mangas 'Surpresa' utilizando recobrimento com película de fécula de mandioca. Os frutos foram mergulhados em suspensões a 0; 1; 2 e 3% de fécula de mandioca por três minutos, secos ao ar e armazenados em temperatura ambiente (± 29º C e ± 87% de umidade relativa. O delineamento utilizado foi o inteiramente casualizado, em fatorial de 4 x 5 (tratamentos x tempo. Foram avaliados a perda de massa fresca (%, a firmeza do fruto e da polpa, a acidez total titulável, os sólidos solúveis totais, a relação SST/ATT e o pH, além das cores da casca e da polpa. Os frutos foram avaliados aos 0; 3; 6; 9 e 12 dias. Os frutos tratados com 3% de fécula de mandioca reduziram a perda de água e melhoraram o aspecto visual dos frutos, e a logevidade deste tratamento foi de 12 contra 7 dias da testemunha.The mango is a tropical climacteric fruit that ripens quickly after having been picked. The useful postharvest life of 'Surpresa' mangos was evaluated using covering with cassava starch film. The fruits were immersed in suspensions to 1, 2 and 3% of cassava starch for three minutes, dried by the air and conserved in ambient temperature at ± 29º C of temperature and ± 87% of relative humidity. The outline used was entirely randomized and the experiment was carried out in 4 x 5 fatorial design (treatments x time. The loss of fresh mass (%, the firmness of the fruit and pulp, the total titratable acidity (TTA, the total soluble solids (TSS, the TSS/TTA relation and the pH, were evaluated besides of the colors of the peel and pulp. The fruits were evaluated on the 0, 3, 6, 9 and 12 days. The fruits treated with 3% of cassava starch reduced its loses of water and improved the visual aspect of the fruits, and the shelf life of this treatment was 12 against 7 days of the witness.

  7. Preparation and properties of resistant starch from fresh cassava%鲜木薯抗性淀粉的制备与性质

    Institute of Scientific and Technical Information of China (English)

    薛慧; 闫庆祥; 蒋盛军; 张国治; 台建祥; 吕飞杰

    2013-01-01

    Many studies have shown that resistant starch has health benefits such as preventing colon cancer, reducing the risk of ulcerative colitis, increasing absorption of minerals, inhibiting fat accumulation and hypoglycemic effects. In this study, the cassava starch was used as raw material. The resistant starch was prepared by autoclaving assisted enzyme treatment. To improve the content of resistant starch, the parameters of enzyme treatment that include adding amounts ofα-amylase, reaction time ofα-amylase, adding amounts of pullulanase and reaction time of pullulanase were optimized with a response surface methodology. The F-value of 57.58 implies the model is significant. The Lack of Fit F-value of 1.66 implies the Lack of Fit is not significant relative to the pure error. The Pred R-Squared of 0.9156 is in reasonable agreement with the Adj R-Squared of 0.9659 and the R-Squared is 0.9829. This model can be used to navigate the design space. The optimized conditions were that when 10%of the starch slurry concentration was autoclaved at 120℃ for 80min, added 1Uα-amylase per gram of starch to react 15.75 min at 95℃, debranched with 0.83U pullulanase per gram of starch at 55℃ for 5.86h, then treated with ultrasonic for 2min, and finally retrograded at 4℃ for 24h to improve resistant starch formation, the content of resistant starch increased to 15.48%. Compared with raw starch, the granule appearance of resistant starch changed under scanning electron microscopy. X-ray diffraction showed that the cassava starch had an A type pattern with sharp peaks at 15°, 17°, 18°and 23°. However, the resistant starch had a B type pattern with sharp peaks at 17°and 22°. The crystallinity of resistant starch improved with increasing resistant starch content. The in vitro digestion results indicated that total carbohydrate digestion products were decreased with increasing resistant starch content and that digestion rates were decreased with increasing incubation time

  8. Envejecimiento de Almidones Termoplásticos Agrios de Yuca y Nativos de Papa por Microscopía de Fuerza Atómica Ageing of Sour Cassava and Native Potato Thermoplastic Starches by Atomic Force Microscopy

    Directory of Open Access Journals (Sweden)

    Harold A Acosta

    2006-01-01

    Full Text Available En este trabajo, se determinó la topografía de almidones termoplásticos (TPS agrio de yuca y nativo de papa, mediante microscopía de fuerza atómica (AFM, durante un periodo de 120 días de almacenamiento. Mezclas de almidones agrios (fermentados de yuca y nativo de papa, y glicerina, se procesaron en un extrusor de husillo sencillo. Láminas de TPS agrio de yuca (SCTPS y nativo de papa (NPTPS, se observaron y midieron por AFM (en modo contacto. Sus superficies mostraron incremento en rugosidad y partes lisas solo a altos contenidos de plastificante, pero SCTPS siempre tuvo menor rugosidad que NPTPS, debido a la fermentación natural del almidón agrio. Estos cambios se relacionaron con el tamaño, la forma del gránulo y particularmente con el contenido de plastificante. Los NPTPS de mayor rugosidad presentaron separación de fases a los 120 días, dada la retrogradación de las moléculas del almidón, que tienden a formar cristalitos. Estos resultados indican que el almidón agrio de yuca puede retardar la retrogradación de almidones termoplásticos, lo cual es importante durante el desarrollo de nuevos empaques biodegradables.This study reports on the topography of thermoplastic starches (TPS from sour cassava and native potato using atomic force microscopy (AFM, over a 120 day-storage period. Mixtures of sour cassava (fermented and native potato starches plus glycerine, were processed using a single-screw extruder. Sour cassava thermoplastic starch (SCTPS and native potato thermoplastic starch (NPTPS films were observed and measured by AFM (in contact mode. Their surfaces showed increased rugosity, and smooth parts only at high plasticizer content. However, SCTPS always had lower rugosity than NPTPS, due to the natural fermentation of sour cassava starch. These changes were related to starch granule size and shape, and particularly to plasticizer content. NPTPS with higher rugosity presented phase separation at 120 days, due to

  9. Study on the properties of cassava hydroxypropyl and octenyl succinic anhydride compound modified starch%木薯羟丙基化辛烯基琥珀酸酯化复合改性淀粉的性质研究

    Institute of Scientific and Technical Information of China (English)

    雷欣欣; 张本山; 周雪

    2012-01-01

    以木薯淀粉为原料制备木薯羟丙基化辛烯基琥珀酸酯化复合改性淀粉,采用傅里叶变换红外谱仪、扫描电镜、X射线衍射仪和Brabender黏度仪等对木薯羟丙基化辛烯基琥珀酸酯化复合改性淀粉的物化性质进行了测定和分析.并与木薯原淀粉和木薯辛烯基琥珀酸淀粉酯进行对比。结果表明,木薯淀粉经复合改性后,在1550-1610cm-1出现新的吸收峰.与原木薯淀粉和木薯SSOS相比,在940、880、730、570cm-1处呈现较弱的吸收峰;复合改性后颗粒表面受损严重.颗粒的形状也发生明显改变,但晶体类型没有发生改变;乳化性能和透明度得到提高;起糊温度、峰值温度降低.糊粘度增大;与单一的辛烯基琥珀酸酯化改性淀粉相比,热糊稳定性升高,凝沉性增强。%The cassava starch was used to prepare cassava hydroxypropyl and octenyl succinic anhydride compound modified starch. The physical properties of cassava hydroxypropyl and octenyl succinic anhydride compound modified starch were investigated by Fourier transform infrared spectrometer(FT-IR),Scanning electron microscop,X-ray diffraction(XRD),Brabender viscometer and so on with the comparison of the native cassava starch and octenyl succinic anhydride(OSA)-modified cassava starch. The results indicated that the FT-IR spectrum of compound modified cassava starch showed new absorption peaks at 1550-1610cm-1. and weaken absorption peak at the 940,880,730 and 570cm-1,compared with the native cassava starch and OSA- modified cassava starch. The starch granule exhibited rougher surface,more irregular shape significantly but the crystalline was not changed. The product showed good emulsifiability and transparency. That gelatinization temperature and the peak temperature all decreased,and paste viscosity was higher as well.The setback capacity was weaker,and hot paste stability increased,compared with single octenyl succinic anhydride

  10. Modification on liquid retention property of cassava starch by radiation grafting with acrylonitrile. I. Effect of γ-irradiation on grafting parameters

    Science.gov (United States)

    Kiatkamjornwong, S.; Chvajarernpun, J.; Nakason, C.

    1993-07-01

    Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85°C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to gamma-rays. A thin aluminum foil was used to cover the inner wall of the reaction vessel, so that the homopolymer concentration was reduced to be less than 1.0% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmation of graft copolymerization and saponification reactions was made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the total dose on the extent of the grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis.

  11. Biological synthesis of Au nanoparticles using liquefied mash of cassava starch and their functionalization for enhanced hydrolysis of xylan by recombinant xylanase.

    Science.gov (United States)

    Zeng, Sumei; Du, Liangwei; Huang, Meiying; Feng, Jia-Xun

    2016-05-01

    Au nanoparticles (AuNPs) have shown the potential for a variety of applications due to their unique physical and chemical properties. In this study, a facile and affordable method for the synthesis of AuNPs via the liquefied mash of cassava starch has been described and the functionalized AuNPs by L-cysteine improved activity of recombinant xylanase was demonstrated. UV-Vis absorption spectroscopy, transmission electron microscopy, and zeta potential measurements were performed to characterize the AuNPs and monitor their synthesis. The presence of Au was confirmed by energy-dispersive X-ray spectroscopy (EDX) and the X-ray diffraction patterns showed that Au nanocrystals were face-centered cubic. The C=O stretching vibration in the Fourier transform infrared spectrum of AuNPs suggested that the hemiacetal C-OH of sugar molecules performed the reduction of Au(3+) to Au(0). The presence of C and O in the EDX spectrum and the negative zeta potential of AuNPs suggested that the biomolecules present in liquefied cassava mash were responsible for the stabilization of AuNPs. The surface of AuNPs was easily functionalized by L-cysteine, which improved the stability of AuNPs. Moreover, cysteine-functionalized AuNPs could significantly improve recombinant xylanase efficiency and stability. PMID:26864877

  12. Thermal and pasting properties of cassava starch-dehydrated orange pulp blends Propriedades térmicas e de pasta de misturas de fécula de mandioca e polpa cítrica

    OpenAIRE

    Magali Leonel; Luciana Bronzi de Souza; Martha Maria Mischan

    2011-01-01

    Instant mixtures are easy to prepare and frequently present functional appeals. A quality parameter for instant mixtures is their rheological behavior. This study aimed at evaluating the effects of extrusion parameters on the pasting properties of cassava (Manihot esculenta L.) starch and dehydrated orange (Citrus sinensis (L.) Osbeck) pulp mixtures. The variable parameters were moisture of mixtures (12.5 to 19%), barrel temperature (40 to 90ºC) and screw rotation (170 to 266 rpm). The extrud...

  13. Changes in physical properties of extruded sour cassava starch and quinoa flour blend snacks Mudanças nas propriedades físicas de snacks extrusados de misturas de polvilho azedo e farinha de quinoa

    OpenAIRE

    Lívia Giolo Taverna; Magali Leonel; Martha Maria Mischan

    2012-01-01

    Given the broad acceptance of sour cassava starch biscuits in Brazil and the nutritional quality of quinoa flour, this study aimed to evaluate the effect of extrusion temperature, screw speed, moisture, and amount of quinoa flour on the physical properties of puffed snacks. Extrusion process was carried out using a single-screw extruder in a factorial central composite design with four factors. Effects of moisture and amount of quinoa flour on the expansion index and specific volume of snacks...

  14. 木薯抗性淀粉的酶法制备研究%Resistant Starch of Cassava Preparation by Enzymatic Hydrolysis

    Institute of Scientific and Technical Information of China (English)

    刘婷; 林莹; 古碧; 谭瑶瑶; 查春月; 吴亨

    2012-01-01

    Thermostable a-amylase or pullulanase was used for enzymatic hydrolysis of cassava starch, resistant starch yield of indicators to investigate the enzymatic hydrolysis kinetics of the process of its preparation. The results showed that resistant starch (RS) content was increased first and then less, with the increasing amount of enzyme thermostable a-amylase. RS content was up to 9.13% when the amount of enzyme was 30 U/g of starch reacted 10 min. RS content was increased first and then decreases with increasing degree of hydrolysis DE value trends, and the RS content was up to 9.13% when the DE value was 0.32. Pullulanase hydrolysis of cassava starch hydrolysis curve was followed a reaction equation. The RS content was up to 10.42% when the amount of enzyme was 4U/g of starch roled for 4 h, by that time the debranching degree was 28.51%. RS were significantly increased in the use of both thermostable a-amylase and pullulanase, which would improve the efficiency of preparation of the RS to the theoretical basis by used the complex enzyme.%以木薯淀粉为原料,使用耐高温α-淀粉酶或普鲁兰酶进行酶解,以抗性淀粉得率为指标探讨其制备过程的酶解动力学。结果表明利用耐高温α-淀粉酶制备抗性淀粉(KS),其RS含量随酶用量先增后减,在酶用量30U/g淀粉作用10min抗性淀粉含量达最高为9.13%;RS含量随水解程度DE值的增大呈先增后减趋势,DE值为0.32时抗性淀粉含量最高为9.13%;木薯淀粉的普鲁兰酶水解曲线遵循一级反应方程,在添加酶量为4U/g淀粉作用时间为4h,脱支度为28.51%时抗性淀粉含量达最高10.42%。耐高温α-淀粉酶和普鲁兰酶均能使抗性淀粉含量显著增加,这将为使用复合酶制备抗性淀粉提高其效率奠定理论基础。

  15. Energetic potential of biogas produced from cassava starch wastewater using a pilot scale two-stage anaerobic biodigester; Potencial energetico do biogas gerado no tratamento de aguas residuarias de fecularias em sistema piloto de biodigestao anaerobia com separacao de fases

    Energy Technology Data Exchange (ETDEWEB)

    Feiden, Armin [Universidade Estadual do Oeste do Parana (UNIOESTE), Marechal Candido Rondon, PR (Brazil). Centro de Ciencias Agrarias]. E-mail: armin_feiden@yahoo.com.br; Cereda, Marney Pascoli [UNESP, Botucatu, SP (Brazil). Centro de Raizes Tropicais

    2003-06-01

    Cassava starch is extracted in more of 70 units in west of Parana state, South of Brazil. Near the border of the Parana river there is a big concentration of this type of industry. The cassava starch extraction generates a great quantity of wastewater. The aim of this work was to evaluate the energetic potential of biogas generated in the anaerobic treatment of cassava. The pilot reactors were located at a cassava processing factory, with cassava roots grauding capacity of 250 metric ton day{sup -1} at the parallel 24 deg 09'18'' South latitude and meridian 54 deg 09'26'' West longitude of Grw. The treatment pilot system was consisted of two settling tanks with 500 L each, connected in series, followed by a two-stage anaerobic biodigester reactor. The acidogenic reactor had a capacity of 1,000 L and the methanogenic had a capacity of 3,000 L. The experiment was conducted at temperatures ranging from 23.9 deg C to 27.7 deg C, with a annual average of 25.8 deg C. It was not used the addition of nutrients nor pH correction. The best results were obtained at a flow rate of 901 L d{sup -1} with a TOC (total organic carbon) loading rate of 0.565 g L{sup -1} d{sup -1} and COD (chemical oxygen demand) of 2.49 g L{sup -1} d{sup -1}, and a hydraulic residence time of 4.4 days. At this loading rate, the system had an average biogas yield of 3.975 L L{sup -1} wastewater 0.895 L L{sup -1} reactor day{sup -1}, and 0.391 L g{sup -1} TOC removed. The net biogas yield was 16.10 m{sup 3} ton{sup -1} cassava roots processed, with 28.65% CO{sub 2}. By calculation it was found that the biogas production is enough to supply 30% of the heat necessity to steam production of the industry, 100% of the heat necessity of direct drying of cassava starch, or 50% of the general total electricity need of the factory. (author)

  16. Screening and Identification of a Raw Cassava Starch-hydrolyzing Asper-gillus Strain and Its Characteristics of Starch Degradation%一株降解生木薯淀粉的曲霉菌株的筛选、鉴定及其淀粉降解特性

    Institute of Scientific and Technical Information of China (English)

    宋贤冲; 田会会; 陈国利; 许剑; 樊宪伟; 李有志

    2011-01-01

    本研究利用以生木薯淀粉为唯一碳源的筛选培养基,从腐烂木薯渣中分离筛选出一株可以降解生木薯淀粉的真菌菌株RSDF-7.根据RSDF-7形态和18S rDNA与28S rDNA之间的内转录间隔区(internal transcribed spacer,ITS)序列分析的结果,初步认定该菌株为曲霉属.菌株RSDF-7的粗酶液对多种不同的生淀粉底物均有水解效果;在以大米和玉米淀粉为底物时,其生淀粉分解活力比较高,分别为42%和40%.菌株RSDF-7的粗酶液具有良好的低pH稳定性,对生木薯淀粉的最适作用温度为50℃,最适作用pH为4.5.在30 min的吸附后,RSDF-7的粗酶液对生木薯淀粉的吸附力高达60%.使用HPLC对粗酶液的酶解产物进行检测,结果发现酶解产物中仅存在葡萄糖,表明菌株RSDF-7所产的生淀粉降解酶主要为糖化酶.扫描电镜观察结果发现,经RSDF-7粗酶液酶解后的生木薯粉颗粒破裂,形成空洞,说明RSDF-7粗酶液对生淀粉有较强的水解作用.可以预见,经纯化后的曲霉菌株RSDF-7生淀粉酶将来可以用于基于酶解的木薯淀粉转化.%A raw cassava starch-hydrolyzing fungal, numbered as RSDF-7, was isolated and screened from the decayed cassava dreg using the screening medium with raw cassava starch as the sole carbon resource. The crude enzyme of strain RSDF-7 showed the better stability within a lower range of pHs. The optimum temperature for digestion of raw starch was 50°C, and the optimum pH was at 4.5. The crude enzyme from the culture of RSDF-7 could hydrolyze several different raw starch substrate, the values of raw starch-degrading ability were higher, with about 42% and 40% using corn and rice starch as the substrate, respectively. Analysis of the morphology and internal transcribed spacer region sequence between 18S rDNA and 28S rDNA indicated that the RSDF-7 belongs to Aspergillus sp.. The absorption rate of raw cassava starch by RSDF-7 was about 60% after 30 min adsorption. Assay of high

  17. Extração da fécula retida no resíduo fibroso do processo de produção de fécula de mandioca Starch extraction from cassava fibrous residue

    Directory of Open Access Journals (Sweden)

    Magali LEONEL

    2000-04-01

    Full Text Available A melhoria do processo de extração da fécula de mandioca é um problema bastante discutido entre industriais e pesquisadores. Atualmente, para cada tonelada de raiz de mandioca processada obtêm-se por volta de 250kg de fécula e perde-se no resíduo fibroso cerca de 140kg de fécula que não foi extraída no processamento. Neste trabalho objetivou-se analisar o efeito de uma segunda extração em paralelo e o uso de soluções auxiliares na extração da fécula retida no resíduo fibroso (farelo, visando a melhoria no rendimento industrial. Foram avaliados quatro tratamentos utilizando-se: água (T1, solução de NaOH 0,2% (T2, solução água-álcool 10%v/v (T3 e solução água- Tween 80 0,002% (T4. A partir dos resultados obtidos foi possível concluir que a adição de soluções auxiliares não promoveu diferença significativa (pImprovement of the extraction process of cassava starch is a problem for researchers and industries in Brazil. In the extraction process of cassava starch for each ton of processed root, 250kg of the starch is produced and about 140kg of the starch is wasted in the cassava fibrous residue. A new extraction and auxiliary solutions were evaluated aiming the improvement of the industrial yield. The use of a second extraction, without auxiliary solutions, was possible to recover 20% of the starch that was not extracted in the traditional process.

  18. Cassava, yam, sweet potato and ñampi starch: functional properties and possible applications in the food industry. Harinas y almidones de yuca, ñame, camote y ñampí: propiedades funcionales y posibles aplicaciones en la industria alimentaria.

    OpenAIRE

    Pedro Vargas Aguilar; Diana Hernández Villalobos

    2013-01-01

    A technical review was conducted to related physical and chemical properties of flours and starches from cassava, yams, taro and sweet potato. Amyloseamylopectin content, viscosity, nutritional value and fiber, were studied to relate them with starch functional properties. A relationship was obtained between amylose-amylopectin, viscosity and fiber content with the digestibility of those starches and the glycemic index values. The use of fermentation to enhance the nutritional value of these ...

  19. 交联羧甲基玉米淀粉和交联酯化木薯淀粉的制备与性质研究%Study on preparation and properties of cross-linked carboxymethyl corn starch and cross-linked esterified cassava starch

    Institute of Scientific and Technical Information of China (English)

    史娟; 杨海涛

    2011-01-01

    The optimum synthesis conditions of the cross-linked carboxymethyl corn starch and cross-linked esterified cassava starch and the key factors affecting the degree of substitution were studied. The physical properties of the two kinds of composite-modified starch, such as freeze-melt stability, light transmissivity, expansibility, were determined. The results showed that the freeze-melt stability, light transmissivity, expansibility of composite-modified starch all improved compared to the n-ative starch,and the cross-linked esterified cassava starch could be used in polluted water with better flocculation effect.%研究了制备交联羧甲基玉米淀粉和交联酯化木薯淀粉的最佳工艺条件及影响取代度的关键因素,并测定了两种复合变性淀粉的冻融稳定性、透光率、膨胀度等特性.结果表明:两种复合变性淀粉的冻融稳定性、膨胀度、透光率等性能均优于原淀粉;交联酯化木薯淀粉具有良好的絮凝效果可用于污水处理.

  20. Biscoitos de polvilho azedo enriquecidos com fibras solúveis e insolúveis Fermented cassava starch biscuits enriched with soluble and insoluble fibers

    Directory of Open Access Journals (Sweden)

    Flavio Martins Montenegro

    2008-12-01

    Full Text Available O presente trabalho avaliou a utilização de farelo de trigo e polidextrose como fontes de fibra no enriquecimento de biscoitos de polvilho. Utilizou-se a Metodologia de Superfície de Resposta para verificar a influência da adição destes ingredientes nos parâmetros de qualidade dos biscoitos. As respostas avaliadas do planejamento experimental fatorial completo 2² foram o volume específico, a dureza instrumental, a umidade e a cor - parâmetros L, a* e b*. Para as respostas: volume específico e dureza instrumental, todos os fatores foram significativos, a 95% de confiança, com R² = 0,9307 e 0,8091, respectivamente. Pela análise das superfícies geradas, pode-se observar que o farelo de trigo e a polidextrose reduziram o volume específico e o farelo teve maior efeito no aumento da dureza. A substituição de polvilho azedo por farelo de trigo e polidextrose nas proporções de 1,5 e 5%, respectivamente, gerou uma amostra rica em fibras, com 6,23% de fibra alimentar (calculado teoricamente, sem prejuízo considerável para as características de expansão e dureza, e com boa aceitação sensorial.This work evaluated the use of wheat bran and polidextrose as fiber sources to enrich fermented cassava starch biscuits. The Response Surface Methodology was used to verify the influence of the addition of these fiber sources on the quality parameters of the biscuits. The responses of the 2² central composite rotational experimental design that were evaluated were specific volume, hardness, and moisture and color - parameters L, a*, and b*. For the specific volume and hardness responses, all factors were significant: 95% confidence level, with R² of 0.9307 and 0.8091, respectively. Analyzing the surfaces obtained it could be observed that the wheat bran and polidextrose reduced the specific volume and the wheat bran had a greater effect in increasing hardness. The substitution of fermented cassava starch by wheat bran and polidextrose in

  1. 地膜覆盖对木薯生长发育和产量及淀粉含量的影响%Effects of Plastic Film Mulching on Development and Yield and Starch Content of Cassava

    Institute of Scientific and Technical Information of China (English)

    韦威旭; 韦民政; 覃维治; 陆柳英; 唐秀桦; 韦哲; 何虎冀; 甘秀芹; 韦本辉

    2009-01-01

    [Objective] The study was to explore cultivation techniques with less cost and high benefit for cassava.[Method] 2 planting patterns of plastic film mulching and no mulching (CK) were taken to plant cassava, the effects of plastic film mulching on growth of stem and leaf, yield components and starch content of cassava were studied.[Result] Plastic film mulching could improve the growth of stem and leaf of cassava at early and middle stage and increase the biomass of cassava.After plastic film mulching, the length and diameter of root tuber, number and weight of root tuber per plant and fresh root tuber yield per plot of cassava were increased by 17.79%, 14.61%, 14.28%, 76.14%, 76.09% resp.than that of CK.After plastic film mulching the starch content of cassava was decreased by 2% than that of CK, while the starch yield of cassava of the same area was increased by 65.35% than that of CK.[Conclusion] Plastic film mulching was the effective measurement of cultivation with less cost and high benefit for cassava, the yield increasing effect was realized through promoting stem and leaf growth of cassava at early and middle sate, improving root tuber diameter and root tuber weight per plant, and increasing the plumpness of root tuber.%[目的]探索木薯节本增效栽培技术.[方法]分别采用地膜覆盖与不覆膜(对照)2种方式种植木薯,研究地膜覆盖对木薯茎叶生长、产量构成因素及淀粉含量的影响.[结果]地膜覆盖可促进木薯前中期茎叶生长,增加木薯生物量;地膜和覆盖后,木薯的块根长度、块根直径、单株块根数、单株块根重和小区鲜块根产量分别较对照增加了17.79%、14.61%、14.28%、76.14%和76.09%;地膜覆盖后木薯的淀粉含量较对照降低2%,但相同面积木薯的淀粉产量较对照增加65.35%.[结论]地膜覆盖是木薯节本增效栽培的有效措施,其增产效应主要是通过促进木薯前中期茎叶生长、提高块根直径和

  2. Cross-linking reaction kinetics of non-crystalline cassava starch in middle and high temperature wet processes%非晶化木薯淀粉交联反应动力学

    Institute of Scientific and Technical Information of China (English)

    罗明辉; 邓燕芳; 卢龙

    2013-01-01

    以非晶化木薯淀粉为原料,通过湿法交联合成淀粉磷酸酯,研究了非晶化木薯淀粉交联反应动力学过程,计算出表观活化能 Ea,讨论了不同温度对交联反应速率的影响。通过与木薯原淀粉湿法交联对比,研究了非晶化处理对淀粉后续反应的影响。结果表明,非晶化处理后,淀粉交联反应的反应取代度和反应程度均提高,表观活化能降低了23%,反应活性得到大大提高。%The starch diphosphate was synthesized by non-crystalline cassava starch through wet process. The influence of temperature on reaction rate was discussed.The kinetics and apparent activation energy of non-crystalline cassava starch in cross-linking reaction were studied.Compared with raw cassava starch,the influence of non-crystallization on consequent reaction was studied.The results showed the degree of sub-stitution and extent of reaction were both increased after non-crystallization,the apparent activation energy was descended by 23%,and the reaction activity was improved.

  3. Synthesis of Superabsorbent Polymer of Cassava Starch Grafting Acrylic Acid%木薯淀粉-丙烯酸接枝共聚合成高吸水性树脂

    Institute of Scientific and Technical Information of China (English)

    樊红日; 张立颖; 黎洪; 尹丽

    2011-01-01

    [ Objective] The research aimed to study the synthesis of superabsorbent polymer by cassava starch. [ Method] Using acrylic acid and cassava starch as raw material, ammonium persulfate and anhydrous sodium sulfite as initiator, superabsorbent polymer was synthesized by aqueous solution polymerization. The effect of monomer-starch ratio, reaction temperature, reaction time, acrylic acid and its neutralization degree and the initiators dosage on the water absorption of the product were investigated. [ Result ] Water absorbency in deionized water and salt water of 0.9% NaCl were 1 844 g/g and 224 g/g respectively at room temperature within 1 h. [ Conclusion ] The study provided scientific basis for preparing superabsorbent polymer with acrylic acid and cassava starch.%[目的]研究木薯淀粉合成高吸水性树脂.[方法]以木薯淀粉和丙烯酸单体为原料,过硫酸铵-亚硫酸钠为引发剂,通过水溶液聚合法制得淀粉基高吸水性树脂.考察了淀粉与单体配比、反应温度、反应时间、中和度和引发剂用量等因素对产品吸水率的影响.[结果]得出产品在室温下1 h内吸去离子水1 844 g/g、0.9%NaCl盐水224 g/g.[结论]该研究为以木薯淀粉与丙烯酸为原料制备高吸水树脂提供科学依据.

  4. Growth kinetics of Saccharomyces cerevisiae in batch and fed-batch cultivation using sugarcane molasses and glucose syrup from cassava starch.

    Science.gov (United States)

    Win, S S; Impoolsup, A; Noomhorm, A

    1996-02-01

    Growth kinetics of Saccharomyces cerevisiae in glucose syrup from cassava starch and sugarcane molasses were studied using batch and fed-batch cultivation. The optimum temperature and pH required for growth were 30 degrees C and pH 5.5, respectively. In batch culture the productivity and overall cell yield were 0.31 g L-1 h-1 and 0.23 g cells g-1 sugar, respectively, on glucose syrup and 0.22 g L-1 h-1 and 0.18 g cells g-1 sugar, respectively, on molasses. In fed-batch cultivation, a productivity of 3.12 g L-1 h-1 and an overall cell yield of 0.52 g cells g-1 sugar were achieved in glucose syrup cultivation and a productivity of 2.33 g L-1 h-1 and an overall cell yield of 0.46 g cells g-1 sugar were achieved in molasses cultivation by controlling the reducing sugar concentration at its optimum level obtained from the fermentation model. By using an on-line ethanol sensor combined with a porous Teflon tubing method in automating the feeding of substrate in the fed-batch culture, a productivity of 2.15 g L-1 h-1 with a yield of 0.47 g cells g-1 sugar was achieved using glucose syrup as substrate when ethanol concentration was kept at a constant level by automatic control.

  5. PREPARATION AND CHARACTERIZATION OF CO-PROCESSED EXCIPIENT-PREGELATINIZED CASSAVA STARCH PROPIONATE AS A MATRIX IN THE GASTRORETENTIVE DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Junaedi

    2011-11-01

    Full Text Available The gastroretentive dosage form is designed to prolong the gastric residence time of the drug delivery system whichalso results in the development of an appropriate excipient. The purpose of this study is to develop and characterize coprocessedexcipient made from carrageenan (kappa-iota = 1:1 and pregelatinized cassava starch propionate (PCSP inratios of 1:1, 1:2, and 1:3. PCSP was prepared with propionic anhydride in an aqueous medium. The product was mixedwith carrageenan (kappa-iota = 1:1, as well as characterized physicochemical and functional properties. The coprocessedexcipient was then used as a mucoadhesive granule and floating tablet. The USP Basket was selected toperform the dissolution test of the granules in HCl buffer (pH 1.2 and distilled water for 8 hours each. Mucoadhesiveproperties were evaluated using bioadhesive through a vitro test and wash-off test. As for the floating tablet, the USPPaddle was selected to perform the dissolution test of the tablets in 0.1 N HCl for 10 hours. The floating lag time andfloating time were tested in 0.1 N HCl for 24 hours. The result of these studies indicated that co-processed excipientcarrageenan-PCSP can retard dosage form in gastric and drug controlled release, thus making it a suitable material forthe gastroretentive dosage form.

  6. Separation and Purification of Amylose and Amylopectin from Cassava Starch and Content Determination by Dual-wavelength Spectrophotometry%双波长法测定木薯淀粉中直链和支链淀粉的含量

    Institute of Scientific and Technical Information of China (English)

    石海信; 郝媛媛; 方怀义; 熊拯

    2011-01-01

    Objective: To separate and purify amylose and amylopectin from cassava starch and to establish a dual-wavelength spectrophotometric method for determining their contents.Methods: The amylose and amylopectin in cassava starch were separated by n-butanol crystallization method.The purity of amylose and amylopectin was characterized by blue value of starch-iodine complex.According to the principle of dual-wavelength spectrophotometry method,the contents of amylose and amylopectin in cassava starch were determined at the selected wavelengths of 624 nm and 538 nm with respective reference wavelengths of 440 nm and 750 nm.Results: The blue values of purified amylose and amylopectin were 0.979 and 0.144,respectively,which were in the distribution range of corresponding standard samples.A high purity of cassava amylose and amylopectin was achieved.An excellent linear relationship between starch-iodine complex and absorbance was achieved in the range of 0-80 mg/L(r=0.9992) for amylose and 0-220 mg/L(r=0.9995) for amylopectin.Conclusion: n-butanol crystallization method amylose and amylopectin from cassava starch.The developed dual-wavelength spectrophotometry method is convenient,accurate and suitable for determining the contents of amylose and amylopectin in cassava starch simultaneously.%目的:分离纯化木薯淀粉中的直链和支链淀粉,建立同时测定木薯淀粉中直链与支链淀粉含量的双波长法。方法:采用正丁醇结晶法分离纯化直链和支链淀粉,蓝值比较法表征直链与支链淀粉的纯度;根据双波长法原理,分别在测定波长624、538nm,参比波长440、750nm处测定木薯淀粉中直链与支链淀粉含量。结果:分离纯化得到的直链与支链淀粉蓝值分别为0.979和0.144,分别落在0.8~1.2与0.08~0.22范围内,表明纯化后木薯直链与支链淀粉的纯度较高;直链淀粉在0~80mg/L质量浓度范围内其碘复合物与吸光度呈线性关系(r=0.9992

  7. 十二烷基苯磺酸木薯淀粉酯微波法制备工艺研究%Preparation technology of dodecyl benzene sulfonic acid cassava starch ester by microwave

    Institute of Scientific and Technical Information of China (English)

    张利伟; 薛行华; 赵法敏; 张永强; 李光

    2013-01-01

    Dodecyl benzene sulfonic acid cassava starch ester was prepared by microwave method with cassava starch as the raw material , sodium dodecyl benzene sulfonate as the esterification agent and sodium hydroxide as the catalyst .The effects of synthetic condition , such as molar ratio ( sodi-um dodecyl benzene sulfonate to glucose unit of cassava starch ) , reaction time , incubated tempera-ture and pH value , on the substitution degree were investigated .The best conditions by orthogonal design were the molar ratio of sodium dodecyl benzene sulfonate to cassava at 0.06 , reaction time 5 h and the incubated temperature 80 ℃, at which the degree of substitution was 0.010 0 .FT-IR and XRD revealed the changes in the structure of the esterified starch , and TG analysis also dis-played the decline of the hydrophilic and thermal stability of the esterified starch .%  以木薯淀粉为原料,十二烷基苯磺酸钠为酯化剂,NaOH为催化剂,采用微波法制备十二烷基苯磺酸木薯淀粉酯,并考察其合成的工艺条件。探讨了十二烷基苯磺酸钠与木薯淀粉葡萄糖单元的摩尔比、反应时间、反应温度和pH值对产物取代度的影响,用正交实验分析对制备工艺进行优化,并通过红外、X射线和热重分析表征了酯化淀粉的结构及其热稳定性。结果表明,在十二烷基苯磺酸钠与木薯淀粉葡萄糖单元摩尔比为0.06、反应时间5 h、反应温度80℃和pH为10的条件下制备的十二烷基苯磺酸酯淀粉的取代度最佳,取代度为0.0100。红外和X射线谱图证明了酯化淀粉结构的改变,热重分析表明酯化淀粉亲水性与热稳定性有所下降。

  8. Effect of growing period on the cassava starch properties of various cassava cultivars%生长期对不同品种(系)木薯淀粉特性的影响

    Institute of Scientific and Technical Information of China (English)

    林莹; 古碧; 李凯; 代道芳

    2011-01-01

    The effect was studied of growing period on the starch properties such as freeze-thaw stability, sediment stability and mean granule size of three cassava cultivars. Freeze-thaw stability was higher and sediment stability was lower in samples harvested at 6th month. The difference of freeze-thaw stability and sediment stability depend on cultivars through the extended growing period. Surface area mean particle size was small and volume mean diameter was large at 6th month. For all cultivars, sediment stability was found to have positively significant correlations with surface area mean particle size. For SE cultivar, sediment stability was positively significant correlated to volume mean particle diameter. For E cultivars, freezethaw stability was negatively significant correlated to surface area mean particle size.%研究生长期对3个品种(SC、E和C)木薯淀粉冻融稳定性、凝沉稳定性和粒径的影响.结果表明,生长期为6个月时,淀粉具有较好的冻融稳定性、较差的凝沉稳定性、较高的体积平均粒径以及较小的表面积平均粒径.相关性分析表明,3个品种木薯淀粉的凝沉稳定性与淀粉表面积平均粒径呈显著正相关,品种SC的淀粉凝沉稳定性与体积平均粒径显著正相关,品种E的冻融稳定性与淀粉表面积平均粒径呈极显著负相关.

  9. Screening of different wheat protease hydrolysates inhibiting retrogradation of corn starch%抑制玉米淀粉回生的面粉蛋白酶解液筛选

    Institute of Scientific and Technical Information of China (English)

    郭俊杰; 康海岐; 孙海波; 连喜军; 李琳

    2014-01-01

    为防止玉米淀粉食品会因回生而降低品质,该文利用酸性、中性和碱性3种蛋白酶水解小麦面粉中的球蛋白、谷蛋白和醇溶蛋白,研究酶解物中混合多肽对玉米淀粉回生的影响。研究结果表明,酸性蛋白酶水解谷蛋白所得多肽混合液能强烈抑制玉米淀粉回生,使玉米淀粉回生率由14.0%降低到8.0%。其他2种水解物促进玉米淀粉回生,促进最多的是碱性蛋白酶水解醇溶蛋白,使玉米淀粉回生率由14.0%升高到19.5%。通过红外和核磁分析了混合多肽抑制或促进玉米淀粉回生的可能机理。研究成果为控制淀粉回生提供一条全新的途径。%Retrogradation is the molecular interaction that occurs between glucan molecules in gelatinized starch during cooling. It profoundly affects quality, acceptability, and shelf-life of starch-containing foods. Corn starch is cheap and is widely used in foods such as instant noodles, sausages, pastries, etc. But the quality of these foods in hardness, digestion, compatibility, etc, becomes deteriorated during storage due to starch retrogradation. Wheat gluten is a kind of nutritious, high quality, and inexpensive plant-based protein. It is often suggested that gluten has an anti-firming effect in bread, but the reason for this is not clear. There are four kinds of proteins in wheat flour:albumin, globulin, glutenin, and gliadin. In order to find the peptides with the ability of hindering corn starch retrogradation, these proteins were hydrolyzed by acid, neutral, and alkali proteases. The effects of these peptides in hydrolysate of globulin, glutenin, and gliadin on the retrogradation of corn starch were carried out in this paper. The results showed that the peptides from hydrolysis of glutenin by acid protease strongly inhibited retrogradation of corn starch, lowering the retrogradation rate of corn starch from 14.0%to 8.0%. Other hydrolysis promoted the retrogradation of corn starch

  10. Simultaneous saccharification of inulin and starch using commercial glucoamylase and the subsequent bioconversion to high titer sorbitol and gluconic acid.

    Science.gov (United States)

    An, Kehong; Hu, Fengxian; Bao, Jie

    2013-12-01

    A new bioprocess for production of sorbitol and gluconic acid from two low-cost feedstocks, inulin and cassava starch, using a commercially available enzyme was proposed in this study. The commercial glucoamylase GA-L NEW from Genencor was found to demonstrate a high inulinase activity for hydrolysis of inulin into fructose and glucose. The glucoamylase was used to replace the expensive and not commercially available inulinase enzyme for simultaneous saccharification of inulin and starch into high titer glucose and fructose hydrolysate. The glucose and fructose in the hydrolysate were converted into sorbitol and gluconic acid using immobilized whole cells of the recombinant Zymomonas mobilis strain. The high gluconic acid concentration of 193 g/L and sorbitol concentration of 180 g/L with the overall yield of 97.3 % were obtained in the batch operations. The present study provided a practical production method of sorbitol and gluconic acid from low cost feedstocks and enzymes.

  11. Effects of Different Added Substances on the Rheological Properties of Hydroxypropyl Cassava Starch Paste%不同添加物对羟丙基木薯淀粉流变特性的影响

    Institute of Scientific and Technical Information of China (English)

    胡珊珊; 王颉; 孙剑锋; 刘亚琼; 牟建楼; 王娜

    2012-01-01

    淀粉糊流变特性是影响淀粉类食品加工品质的主要因素.利用流变仪测定了不同添加物质对羟丙基木薯淀粉流变特性的影响,结果表明:添加不同的物质均未改变羟丙基木薯淀粉糊的流体类型,各流变参数经Herschel-Bulkley模型进行拟合,拟合系数接近1.单甘酯、食盐、柠檬酸使羟丙基木薯淀粉糊的剪切应力不同程度降低,黏稠系数减小,流变特性指数增加;蔗糖酯、酪朊酸钠、黄原胶、CMC、瓜尔豆胶、蔗糖使羟丙基木薯淀粉糊的剪切应力明显提高,黏稠系数增加,流变特性指数减小.%The rheological property of starch pastes is an important influencing factor during the processing of starchy food. The effect of different added substances on the rheological properties of hydroxypropyl cassava starch was measured by rheometer. The results showed that: the fluid type of hydroxypropyl cassava starch was not altered by the different added substance, and the fitting coefficient closed to 1 as the rheological parameters was fitted by the Her-schel - Bulkley model. Monoglycerides,salt and citric acid had the same effect on the hydroxypropyl cassava starch, which made the shear stress reduced to varying degrees, the consistency index decreased and the flow index increased. Contrary to that,sucrose esters,sodium caseinate,xanthan gum,CMC,guar gum made the shear stress significantly increased, the consistency index increased and flow index decreased. The results of this study offered valuable references for the further processing of hydroxypropyl cassava starchy products.

  12. Study on Hydrolysis Process of Cassava Starch Used for Microbial Lipid Fermentation%用于微生物油脂发酵的木薯淀粉水解工艺的优化

    Institute of Scientific and Technical Information of China (English)

    张志斌; 颜日明; 曾庆桂; 汪涯; 朱笃

    2012-01-01

    In order to improve the lipid production of cassava starch, the process of cassava starch hydrolysis (CSH) was optimized using orthogonal experimental design and Uniform design. The results showed that the content of α-amylase and glucoamylase and the liquefaction temperature significantly influenced cassava starch amylolysis. The dextrose equivalent value was up to 97.3% when content of α-amylase and glucose amylase and liquefaction tem-perature were 756 u/g, 602 u/g and 92℃ , respectively. While the CSH was used as a carbon source,the biomass and total lipid content of Trichosporon cutaneum were 16.38g/L and 7.22 g/L respectively, which increased by 46. 25% and 41.12% as compared with those using glucose as a carbon source. Therefore, cassava starch hydrolysis, as a novel carbon source, is an ideal route to produce microbial lipid.%为了提高木薯淀粉的发酵产脂能力,采用正交实验和均匀设计法对木薯淀粉酶法水解工艺进行了优化,结果表明d一淀粉酶量、糖化酶量和液化温度对木薯淀粉水解有显著影响。当淀粉酶量为756U/g,糖化酶量为602U/g,液化温度为92℃,其水解DE值达到97.3%。以该水解液进行皮状丝胞酵母B3(rcutaneumB3)油脂发酵时,其生物量和油脂产量分别为16.38g/L和7.22g/L,比葡萄糖作为碳源的生物量和油脂产量高46.25%和41.12%,利用木薯淀粉水解液作为新型发酵碳源生产微生物油脂是一种理想的途径。

  13. 氧化淀粉的机械活化木薯淀粉干法制备%Dry Preparation of Oxidized Starch by Mechanical Activation of Cassava Strarch

    Institute of Scientific and Technical Information of China (English)

    韦艳枝; 黄祖强; 胡华宇; 余青云; 莫智宇; 张燕娟

    2012-01-01

    Oxidized starch was prepared by dry process during with activation and reaction happened synchronously using self-designed stirred mill as reactor, cassava starch as raw material and peracetic acid as oxidant. The effects of activation time, activation temperature, dosages of oxidant and catalyst on oxidation of starch were investigated by using carboxyl content of oxidized starch as evaluating index. In addition, the functional groups of reaction product were characterized by FI-IR. The results indicated that mechanical activation considerably enhanced the oxidation reaction of cassava starch. Under the conditions of activation time 60min, activation temperature 50℃, dosage of oxidant 3:840%, dosage of catalyst 0.03%, the carboxyl content of oxidized starch was 1.826%. However, under the same preparation conditions without mechanical activation, the carboxyl content of oxidized starch was only 0.039%. The FI-IR spectra showed obvious carbonyl absorption peaks of oxidation starch.%以过氧乙酸为氧化剂、自制的高能效搅拌磨为反应器,采用边活化边反应的方法对木薯淀粉进行干法氧化以制备氧化淀粉.以羧基含量为评价指标,分别考察反应时间、反应温度、氧化剂用量、催化剂用量等因素对淀粉氧化反应的影响,并利用红外光谱仪对产物进行官能团分析.结果表明,机械活化对木薯淀粉过氧乙酸氧化反应有显著强化作用.在反应时间为60 min、反应温度为50℃、氧化剂用量为3.840%、催化剂用量为0.03%时所制得的氧化淀粉羧基含量为1.826%,而在相同条件下,由原木薯淀粉制得的氧化淀粉羧基含量仅为0.039%.红外光谱显示,氧化淀粉出现明显的羰基吸收峰.

  14. Genetic Background Research on RAPD of Cassava with Different Root Starch Phosphorus Contents%块根淀粉磷差异木薯种质资源的RAPD遗传背景研究

    Institute of Scientific and Technical Information of China (English)

    赵凯; 蒋盛军

    2011-01-01

    通过RAPD遗传背景研究方法,从分子水平对木薯块根淀粉磷差异种质资源进行分析,为木薯块根淀粉高磷品种的选育打下基础.以国家木薯种质圃筛选出的30个块根淀粉磷差异木薯品种为材料,采用改良CTAB法提取DNA,通过18条RAPD引物对材料进行PCR扩增,利用NTSYS软件对扩增结果进行了遗传关系分析.结果表明:采用改良的CTAB法提取的DNA可以用于RAPD分析;利用18条RAPD引物扩增共得出条带131条,其中多态性条带126条,多态性百分率为96.2%;其中没有发现与磷含量相关的特异性条带,块根淀粉磷含量相近的木薯品种问不能明显聚类;30个品种间的遗传相似性系数GS大于0.71.通过对RAPD结果进行分析,未发现块根淀粉磷含量差异的木薯品种间存在明显的遗传关系,也未发现与磷元素差异相关的特异基因.%To analyze cassava resource with different phosphorus contents in root starch by using the RAPD genetic background research method from the molecular level, which would lay foundation for the cassava breeding with high phosphorus in root starch. We chose 30 selected cassava varieties with different phosphorus in root starch as the material, which were from the cassava germplasm nursery in the Tropical Crops Genetic Resources Institute of Chinese Academy of Tropical Agriculture. The improved CTAB method was used to extract DNA, and then was for PCR amplification through 18 RAPD primers. The amplification products were conducting the genetic relationship analysis by NTSYS software. The results showed that DNA extracted by the improved CTAB method could be used to do RAPD analysis. Using 18 RAPD primers totally obtained 131 amplification bands, of which were 126 polymorphic bands and the percentage of polymorphism was 96.2%. It didn' t find specific band related with phosphorus content. The cassava resources with similar phosphorus content in root starch can not significantly cluster. The

  15. Effects of processing on physical properties of extruded snacks with blends of sour cassava starch and flaxseed flour

    Directory of Open Access Journals (Sweden)

    Camila De Barros Mesquita

    2013-09-01

    Full Text Available The opportunity to supplement common cassava biscuits with a product of higher nutritional value meets consumer expectations. In this work it was studied the effects of process parameters and flaxseed addition on physical properties of expanded snacks. Extrusion process was carried out using a single screw extruder in a factorial central composite rotatable design with four factors: flaxseed flour percentage (0-20%, moisture (12-20%, extrusion temperature (90-130 °C and screw speed (190-270. The effect of extrusion variables was investigated in terms of expansion index, specific volume, water absorption index, water solubility index, color parameters (L*, a* ,b* and hardness. The data analysis showed that variable parameters of the extrusion process and flaxseed flour affected physical properties of puffed snacks. Among the experimental conditions used in the present study, expanded snack products with good physical properties can be obtained under the conditions of 10% flaxseed flour, 230 rpm screw speed, temperature of 90 °C and moisture of 12%.

  16. 真空制备木薯淀粉超吸水材料%Vacuum Synthesis of Cassava Starch Graft Poly( acrylic acid) of Super Absorbent Polymer

    Institute of Scientific and Technical Information of China (English)

    雷统席; 蒋盛军; 曹阳; 王江; 赵雪娜; 陈郴; 谢娜纯

    2012-01-01

    采用真空技术成功制备了一种木薯淀粉(CS)-g-丙烯酸(AA)超吸水材料。在AA与cS质量比2.5:l,过硫酸钾0.07g,30%wt氢氧化钠水溶液中和度(摩尔比)20%,N,N’-弧甲基双丙烯酰胺0.14%(占AA重)条件下,65℃真空恒温反应3h,干燥后得超吸水材料(cs.SAP)。一定温度湿度条件下,不同形状CS—SAP吸液能力及保水性能有一定差别,保留4%凝胶残重的材料保水时间最长可达28d:材料吸去离予水倍率高达1316.8(g/g)、自来水673.1(g/g)、0.9%NaCI水溶液54.8(g/g)、人工尿液63.0(g/g)。接枝反应及材料吸水结构经FTIR.SEM,PM表征。%In the paper, a superabsorbent polymer was first prepared by vacuum gratt copolymerization of cassava starch and acrylic acid, with potassium persulfate as an initiator, N,N'- methylene diacrylamide as crosslinking agent. The reaction conditions were 2.5 mass ratio of acrylic acid to cassava starch, 0.14 % mass ratio of crosslinker to acrylic acid, initiator 0.07 g, 20 % neutralization degree of acrylic acid (Using a mass percentage of 30 % sodium hydroxide solution); polymerization at 65 ℃for 3 h under vacuum. Different shapes of materials had some differences about water absorption rate and water retention. In a certain temperature and humidity conditions, the retention time of 4 % residual weight of water gel can reach to 28 d. The water-absorbing rate of the prepared resin can reach 1316.8(g/g)at room temperature. The saline water (0.9 % NaCl) absorbency was 54.8(g/g), water absorbency in tap water and in synthetic urine in 24 h was about 673.1 (g/g)and 63.0(g/g). Grafting reaction and structure of CS-SAP characterization by FTIR, SEM, PM.

  17. Effects of Dissolved Oxygen Tension and Ammonium Concentration on Polyhydroxybutyrate Synthesis from Cassava Starch by Bacillus cereus IFO 13690

    Directory of Open Access Journals (Sweden)

    Margono .

    2015-11-01

    Full Text Available generated by an Adobe application 11.5606 Attempting to get low price of raw material for producing polyhydroxybutyrate is always studied. Tapioca starch is one of the raw material with low price. The objective of this research was to study the effects of initial ammonium concentration and dissolved oxygen tension (doT on producing PHB by Bacillus cereus IFO 13690 with tapioca starch as the carbon source. This fermentation was carried out in 5 L fementors with a 2 L working volume, temperature of 30 oC, and agitation of 500 rpm. The pH medium was controlled at 5.6 after it came down from the initial pH of 6.8. Meanwhile, the initial doT was 100 % air saturation and also came down to and maintained at doT of experiment, i.e. 1 , 5 , or 10 % air saturation. The best result was obtained when the initial ammonium concentration was 5 g/L and the doT value maintained at 5 % air saturation. By this conditions, the cell growth reached 5,457 g cell dry weight/L containing PHB of 2.42 % cell dry weigh after 29 hours fermentation. Normal 0 36 false false false

  18. 机械活化固相化学反应制备木薯醋酸酯淀粉%Preparation for cassava starch acetate by mechanical activation-strengthened solid phase chemical reaction

    Institute of Scientific and Technical Information of China (English)

    陈渊; 杨家添; 黄祖强; 朱万仁; 唐春洁; 秦顾

    2013-01-01

    In order to develop a new preparation method of starch acetate,the cassava starch acetate was synthesized by mechanical activation-strengthened solid phase chemical reaction.The effects of acetic anhydride content,sodium hydroxide content,ball-milling temperature,ball-milling time,stirring speed and the volume of the stack for ball-milling media on esterification of cassava starch were investigated.The degree of substitution (DS) of starch acetate was used as the evaluating parameter.The best conditions of preparation technique were confirmed by orthogonal test.The optimum conditions of cassava starch acetate preparation were 60% acetic anhydride,2.0% sodium hydroxide,ball-milling temperature 60℃,ball-milling time 60min,stirring speed 380r/min,tack media 500 mL,the DS of the products 0.2632,and the RE was 25.57%.Furthermore,the structure of native starch and the starch acetate were further characterized by using Fourier transform infrared spectrometry (FTIR) and X-ray diffraction (XRD).The mechanical activation considerably enhanced the esterification of cassava starch.%为获得制备醋酸酯淀粉的新工艺,采用机械活化固相化学反应法制备木薯醋酸酯淀粉.以醋酸酯淀粉的取代度为评价指标,分别探讨醋酸酐用量、NaOH用量、球磨温度、球磨时间、搅拌速度、球磨介质的堆体积等因素对木薯淀粉醋酸酯反应的影响,并对影响因素进行了正交优化.结果表明:在醋酸酐质量分数60%、NaOH质量分数2.0%、球磨温度60℃、球磨时间60 min、搅拌速度380 r/min、球磨介质堆体积500 mL的反应条件下,制备得到的木薯醋酸酯淀粉的取代度为0.263 2,反应效率为25.57%.并采用红外光谱(FTIR)、X-射线衍射(XRD)对木薯醋酸酯淀粉的结构进行了表征.机械活化对淀粉发生酯反应有显著的强化作用.

  19. EVALUASI NILAI GIZI PATI RESISTEN PADA PRODUK KERUPUK DARI EMPAT JENIS PATI [Nutritional Evaluation of Resistant Starch of Crackers Made of Four Kinds of Starch

    OpenAIRE

    R o s i d a

    2009-01-01

    In this research, resistant starch content of crackers (=kerupuk) made of corn starch, cassava starch, sago starch and mungbean starch has been studied. Nutritional evaluation of crackers was conducted in experimental rats. It was found that starch content, amylose content and resistant starch content of sago starch were the highest, while those of mungbean starch were the lowest.Bioassay with rats revealed that starch flour diets had no effect on the water content of digesta, but these diets...

  20. Solid Substrate Fermentation of Cassava Peel for Poultry Feed Ingredient

    Directory of Open Access Journals (Sweden)

    Stephanie

    2013-03-01

    Full Text Available Cassava peel which is not used during cassava starch extraction is one of potential resources for animal feed. However, cassava peel has low level protein content, high level crude fiber, and high level of toxic cyanogenic compound. These problems limit the utilization of cassava peel as feed. Solid substrate fermentation using mold may be a solution process to increase its nutritional value and decrease toxic level of cassava peel. In this paper, matters that related with cassava peel fermentation process are subsequently described, namely: (i problems of cassava peel; (ii biodegradation and detoxification process; (iii solid state fermentation methods on cassava peel; (iv nutritional quality of fermented cassava peel; and (v application of fermented cassava peel in poultry feed. The fermented cassava peel application is compared with those of cassava root and waste (onggok. Addition of nitrogen inorganic in the fermentation process increases the mold growth and protein content of the product, while fiber and cyanogenic contents are decreased due to mold degradation activity. The fermentation process may be carried out using only the cassava peel as the substrate or mixed with wheat flour, using indigenous microbes, Aspergillus niger or a white rot fungus, Panus tigrinus as inoculum. As well as fermented cassava root and waste, fermented cassava peel can be used to substitute maize as poultry feed, although it is reported that the optimum substitution in broiler ration is only 10%.

  1. 处理木薯淀粉废水的厌氧反应器初次启动方法研究%Study on the initial start-up method of anaerobic reactor for treating cassava starch wastewater

    Institute of Scientific and Technical Information of China (English)

    任伯帜; 韦兴浩; 侯保林

    2012-01-01

    对处理木薯淀粉废水的EGSB厌氧反应器初次启动时的接种污泥选择、污泥驯化方法、厌氧反应器控制条件进行研究.当选用木薯酒精厂厌氧发酵污泥作为接种污泥,控制pH在6.8~7.6,VFA<1 000 mg/L,温度在26~28℃时,采用阶段进水驯化方式,经过近100 d的实际运行,成功培养出适应木薯淀粉废水的颗粒污泥,系统COD去除率达86%以上,厌氧反应器启动成功,运行状况良好,处理效果稳定.%everal factors such as the selection of inoculated sludge,method of sludge acclimatization and the condition of the anaerobic reactor control for treating cassava starch wastewater when initially started-up have been studied. When the anaerobic fermented sludge of the cassava alcohol plant is selected as inoculated sludge,its pH should be controlled at 6.8-7.6,VFA<1 000 mg/L,and temperature at 26-28 ℃ ,the influent water acclimatization in phasic mode is used. After running for almost 100 d,the granular sludge that is suitable for cassava starch has successfully been cultivated. Under these conditions,the removing rate of COD could be higher than 86% ,and the anaerobic reactor has started up smoothly and fluently, with stable treatment effect.

  2. 超临界CO2处理对木薯淀粉结构和性质的影响%Effects of supercritical CO2 treatment on structures and properties of cassava starch

    Institute of Scientific and Technical Information of China (English)

    白俊; 李习都; 谢新玲; 张友全

    2016-01-01

    Cassava starch was extracted in different conditions with supercritical carbon dioxide. The morphological characteristics and the gelating properties of the treated starch, such as particle morphology, swelling degree, crystalline structure, viscosity, retrogradation and freeze-thaw stability, were evaluated and compared with native cassava starch by using scanning electron microscope, X-ray diffraction analyzer, Brabender visco-analyser or other methods. As a result, it showed that with the change of the pressure, temperature and time of the treatment, the morphology of the treated starch was not obviously changed, but the swelling degree decreased and the crystallinity increased. It also found that the anti-precipitability of the treated starch gel was strengthened and the freeze-thaw stability reduced. Meanwhile, Brabender viscosity analysis suggested that the gelation temperature of the treated starch could be slightly raised and the peak viscosity of the treated starch gel decreased, while the thermal stability little changed. All the results indicated that thecassava starch molecules could be partially degraded and the ratio of amylose to amylopectin would increase in the process of supercritical treatment, leading to the alteration of some microstructure characteristics and gelating properties of cassava starch.%采用超临界二氧化碳萃取技术在不同条件下处理木薯淀粉,利用扫描电镜(SEM)、X射线衍射仪(XRD)、布拉班德(Brabender)黏度仪等分析手段,考察超临界处理对木薯淀粉颗粒形貌、膨胀度、结晶结构以及淀粉糊黏度、凝沉性、冻融稳定性等的影响。结果表明,随超临界压力、温度、处理时间的变化,样品颗粒外貌无明显改变,但膨胀度降低,结晶度增大;淀粉糊的凝抗性增强,淀粉凝胶冻融稳定性却降低;Brabender黏度分析显示经超临界处理后的淀粉样品糊化温度小幅度升高,糊峰值黏度降

  3. Effect of organoclay on morphology and properties of linear low density polyethylene and Vietnamese cassava starch biobased blend.

    Science.gov (United States)

    Nguyen, D M; Vu, T T; Grillet, Anne-Cécile; Ha Thuc, H; Ha Thuc, C N

    2016-01-20

    Linear low density polyethylene (LLDPE)/thermal plastic starch (TPS) blend was studied to prepare the biobased nanocomposite material using organoclay nanofil15 (N15) modified by alkilammonium as the reinforced phase. The LLDPE/TPS blend and its nanocomposites were elaborated by melt mixing method at 160 °C for 7 min. And the compounded sample was filmed by blowing method at three different zones of temperature profile which are 160-170-165 °C. The good dispersion of clay in the polymer blend matrix is showed by X-ray diffraction (XRD) and transmission electronic microscopy (TEM), and a semi-exfoliated structure was obtained. The thermal and mechanical properties of materials are enhanced when N15 is added to the mixture. The effect of N15 on morphology and particles size of TPS phase is also investigated. The biodegradation test shows that more than 60% in weight of LLDPE/TPS film is degraded into CO2, H2O, methane and biomass after 5 months in compost soil. PMID:26572342

  4. Potential functions of microRNAs in starch metabolism and development revealed by miRNA transcriptome profiling of cassava cultivars and their wild progenitor

    OpenAIRE

    Chen, Xin; Xia, Jing; Xia, Zhiqiang; Zhang, Hefang; Zeng, Changying; Cheng LU; Zhang, Weixiong; Wang, Wenquan

    2015-01-01

    Background MicroRNAs (miRNAs) are small (approximately 21 nucleotide) non-coding RNAs that are key post-transcriptional gene regulators in eukaryotic organisms. More than 100 cassava miRNAs have been identified in a conservation analysis and a repertoire of cassava miRNAs have also been characterised by next-generation sequencing (NGS) in recent studies. Here, using NGS, we profiled small non-coding RNAs and mRNA genes in two cassava cultivars and their wild progenitor to identify and charact...

  5. Características físicas de filmes biodegradáveis produzidos a partir de amidos modificados de mandioca Physical characteristics of cassava modified starch films

    Directory of Open Access Journals (Sweden)

    Celina Maria Henrique

    2008-03-01

    , foram mais permeáveis que o PVC. Porém, quando se compara o filme biodegradável de amidos modificados com o filme comercial de PVC, ainda há muito que se trabalhar na formulação para melhorar várias propriedades deste tipo de embalagem, que tem amplo uso atualmente.Cassava starches may be used as raw materials for developing biodegradable films. Some starch modification processes can make them miscible in cold water and others can modify their film properties, making them stronger and more flexible. The aim of this study was to evaluate the physical characteristics of biodegradable films developed from cassava modified starches using the casting process (dehydration of a filmogenic solution on Petri dishes. The modified starches used were cross linked, low and high viscosity carboxymethyl starches and esterified starch. Starch viscosity is an important property to produce the filmogenic solution and it was tested using the Rapid Visco Analyser (RVA. Excepting cross linked starch, all modified starches presented cold solubility. This property enables an easier preparation of the filmogenic solutions. However, all modified starches presented a severe reduction of setback values, property associated with film formation. The cassava modified starch films were compared to commercial PVC films of 0.0208 to 0.0217 mm thickness. The cassava modified starch films presented thickness values from 0.0551 to 0.1279 mm. The minimum thickness values were observed in pre-gelatinized and cross linked films. The scanning electron microscopy analysis of the films showed differences among the starches. The resulting films were transparent and homogeneous. There was no significant interference of film thickness in water vapor permeability and the films with 5% dry matter were more permeable than the PVC film. However, when modified starch films are compared to PVC commercial films, there is still much research to be made in the formulation to improve several properties necessary to

  6. 一株降解生木薯淀粉的曲霉菌株的筛选、鉴定及其淀粉降解特性%Screening and Identification of a Raw Cassava Starch-hydrolyzing Aspergillus Strain and Its Characteristics of Starch Degradation

    Institute of Scientific and Technical Information of China (English)

    宋贤冲; 田会会; 陈国利; 许剑; 樊宪伟; 李有志

    2011-01-01

    本研究利用以生木薯淀粉为唯一碳源的筛选培养基,从腐烂木薯渣中分离筛选出一株可以降解生木薯淀粉的真菌菌株RSDF-7。根据RSDF-7形态和18SrDNA与28SrDNA之间的内转录间隔区(internal transcribed spacer,ITS)序列分析的结果,初步认定该菌株为曲霉属。菌株RSDF-7的粗酶液对多种不同的生淀粉底物均有水解效果;在以大米和玉米淀粉为底物时,其生淀粉分解活力比较高,分别为42%和40%。菌株RSDF-7的粗酶液具有良好的低pH稳定性,对生木薯淀粉的最适作用温度为50℃,最适作用pH为4.5。在30min的吸附后,RSDF-7的粗酶液对生木薯淀粉的吸附力高达60%。使用HPLC对粗酶液的酶解产物进行检测,结果发现酶解产物中仅存在葡萄糖,表明菌株RSDF-7所产的生淀粉降解酶主要为糖化酶。扫描电镜观察结果发现,经RSDF-7粗酶液酶解后的生木薯粉颗粒破裂,形成空洞,说明RSDF-7粗酶液对生淀粉有较强的水解作用。可以预见,经纯化后的曲霉菌株RSDF-7生淀粉酶将来可以用于基于酶解的木薯淀粉转化。%A raw cassava starch-hydrolyzing fungal,numbered as RSDF-7,was isolated and screened from the decayed cassava dreg using the screening medium with raw cassava starch as the sole carbon resource.The crude enzyme of strain RSDF-7 showed the better stability within a lower range of pHs.The optimum temperature for digestion of raw starch was 50℃,and the optimum pH was at 4.5.The crude enzyme from the culture of RSDF-7 could hydrolyze several different raw starch substrate,the values of raw starch-degrading ability were higher,with about 42% and 40% using corn and rice starch as the substrate,respectively.Analysis of the morphology and internal transcribed spacer region sequence between 18S rDNA and 28S rDNA indicated that the RSDF-7 belongs to Aspergillus sp..The absorption rate of raw cassava starch by RSDF-7 was about 60% after 30 min adsorption.Assay of

  7. Caracterização e análise sensorial de biscoitos de polvilho elaborados com diferentes níveis de farelo de mandioca Characterization and sensory analysis of cassava starch biscuits made with different levels of cassava bagasse

    Directory of Open Access Journals (Sweden)

    Janaína Pereira de Macedo Rodrigues

    2011-12-01

    Full Text Available Objetivou-se com este trabalho avaliar as características químicas, cor, volume específico e aceitabilidade, de biscoitos elaborados com diferentes níveis de farelo de mandioca desidratado. Realizou-se previamente a desidratação do farelo de mandioca e, em seguida, elaboraram-se formulações de biscoitos com concentrações de farelo de mandioca de 0% (BP, 2% (BF2, 4% (BF4, 6% (BF6 e 8% (BF8, em substituição à fécula de mandioca. Os dados foram analisados por meio da análise de variância, teste de Tukey, em nível de 5% de significância. O teor de fibra alimentar e os atributos de cor (L*, a* e b* dos biscoitos aumentaram significativamente com a adição do farelo de mandioca desidratado, o teor de fibra alimentar total variou de 5,47g 100g-1 a 11,40g 100g-1, o de proteínas variou de 6,66g 100g-1 a 7,26g 100g-1. Em 100g de biscoito de polvilho com 8% de farelo de mandioca, encontram-se atendidas 20%, 32%, 26%, 38%, 79%, 16% e 20% da ingestão dietética de referência para o cálcio, cobre, fósforo, magnésio, manganês, potássio e zinco, respectivamente. O volume específico dos biscoitos diminuiu com o aumento de farelo de mandioca. Os biscoitos apresentaram boa aceitabilidade para aparência, sabor e textura. Conclui-se que biscoitos de polvilho elaborados com farelo de mandioca desidratado constituem um produto com bom potencial nutricional e de boa aceitabilidade.This study evaluated the chemically composition, color, specific volume and acceptability of biscuits made with cassava bagasse dehydrated. Held prior to the dehydration of cassava bagasse, then prepared themselves for producing biscuits with concentrations of cassava bagasse from 0% (BP, 2% (BF2, 4% (BF4 6% (BF6 and 8% (BF8, instead of cassava starch. Data were analyzed by analysis of variance, Tukey at 5% level of significance. The dietary fiber content and attributes of color (L*, a* b* the biscuits increased with the addition of cassava bagasse dehydrated, the

  8. Production of the Butyric Acid from Cassava Residue Hydrolysate with Clostridium tyrobutyricum in Fibrous-bed Bioreactor%纤维床固定化酪丁酸梭菌发酵木薯渣水解液生产丁酸的研究

    Institute of Scientific and Technical Information of China (English)

    高振; 江凌; 朱丽英; 林明; 李燕萍

    2012-01-01

    [目的]研究纤维床固定化酪丁酸梭菌发酵木薯渣水解液生产丁酸的可行性.[方法]以酪丁酸梭菌为生产菌株,初步优化了木薯渣的水解条件,并开展了纤维床固定化生物反应器半连续发酵木薯渣水解液生产丁酸的研究.[结果]加压条件下,稀酸水解木薯渣的总还原糖得率达到0.56 g/g.酪丁酸梭菌能有效利用葡萄糖、木糖进行单糖或混合糖发酵生产丁酸;固定化补料流加发酵有利于提高丁酸的产量和得率,降低副产物乙酸的产量和得率;以木薯渣水解液用于固定化批次发酵生产丁酸时,丁酸的产量和得率均较高,分别为(23.20士1.32)g/L和(0.44±0.01) g/g.[结论]木薯渣水解液对丁酸生产菌的生长和代谢没有明显的抑制作用,发酵各参数指标均能达到利用葡萄糖时的同等水平,可作为未来微生物发酵工业化生产丁酸的廉价原料来源.%[Objective] The research aimed to study feasibility for production of the butyric acid from cassava residue hydrolysate by C. Tyro-butyricum immobilized in fibrous-bed bioreactor (FBB). [Method] C. Lyrobutyricum. As producing strain, production of the butyric acid from cassava residue hydrolysate by fibrous-bed bioreactor was studied, as well as optimization for hydrolysis condition of the cassava residue. [ Result] At high pressure, yield for total reducing sugar of the cassava residue hydrolyzed by dilute HC1 was 0.56 g/g. Glucose and xylose could be well utilized by C. Tyrobutyricum to produce butyric acid. The fed-batch immobilized fermentation mode has been successfully used to produce more butyric acid with higher final concentration and yield when compared with the free-cell fermentation mode, together with lower acetic acid output. The fermentation reached a maximum butyric acid concentration of (23. 20 ?1.32) g/L and a yield of (0.44 ?.01) g/g from cassava residue hydrolysate in batch FBB mode. [ Conclusion] Cassava residue hydrolysate

  9. Sensory and physicochemical evaluation of low-fat chicken mortadella with added native and modified starches

    OpenAIRE

    Prestes, R. C.; Silva, L. B.; Torri, A. M. P.; Kubota, E. H.; C.S. ROSA; S.S. ROMAN; Kempka, A. P.; I.M. DEMIATE

    2014-01-01

    The objective of this work was to evaluate the effect of adding different starches (native and modified) on the physicochemical, sensory, structural and microbiological characteristics of low-fat chicken mortadella. Two formulations containing native cassava and regular corn starch, coded CASS (5.0 % of cassava starch) and CORN (5.0 % of regular corn starch), and one formulation produced with physically treated starch coded as MOD1 (2.5 % of Novation 2300) and chemically modified starch coded...

  10. 双波长分光光度法测定木薯块根淀粉含量的动态变化%Time Course of Starch Content in Cassava Root Tuber Determined by Dual- Wavelength Spectrophotometry

    Institute of Scientific and Technical Information of China (English)

    黄惠芳; 罗燕春; 田益农; 付海天; 苏文潘; 彭靖茹; 黎萍; 黄强; 侯学文

    2012-01-01

    以双波长分光光度法测定SC201、SC205、GR891和GR911共4个木薯品种生育期块根中直链淀粉与支链淀粉含量的动态变化.结果表明,4个木薯品种块根直链淀粉的含量是随生育期的延长而逐渐增加的,而支链淀粉的含量却缓慢下降,支链淀粉/直链淀粉的比例呈现下降趋势,到12月份4个品种的这一比例已接近相同;以鲜重计的总淀粉含量,4个品种均呈逐渐增加的趋势;而以干重计的总淀粉含量的变化则4个品种表现不一致.研究初步揭示了木薯块根直链淀粉、支链淀粉和总淀粉含量的积累规律.%The time course of amylase and amylopectin content in root tuber of four cassava cultivars,SC201, SC205 ,GR891and GR911 ,were determined by dual - wavelength spectrophotometry. The results showed that;the am-ylose content of cassava root tuber of four cultivars gradually increase in the time course, however the amylopectin decreased along with the growth period, and the ratios of amylopectin/amylose of four cultivars were decreased continuously , by December, their ratios were very close to 1: 1. The starch content by fresh weight in four cultivars also increased , while the starch content by dry weight in four cultivars were different. This research revealed the accumulation rule of amylose, amylopectin and total starch of cassava root tuber.

  11. Transcriptional response to petiole heat girdling in cassava

    Science.gov (United States)

    The heat-girdling technique, which is known to inhibit photoassimilate translocation, was performed on the petiole of cassava leaves at the end of the light cycle to inhibit starch remobilization during the night. The inhibition of starch remobilization caused significant starch accumulation at the ...

  12. Fécula de mandioca e farinha de aveia como substitutos de gordura na formulação de hambúrguer de carne ovina Cassava starch and oatmeal as fat replacers of lamb burgers

    Directory of Open Access Journals (Sweden)

    Larissa Mont'Alverne Jucá Seabra

    2002-12-01

    Full Text Available Nos produtos cárneos com teor de gordura reduzido, ingredientes têm sido utilizados para manter os atributos de qualidade e rendimento. As farinhas de mandioca e de aveia têm sido usadas como componentes úteis para melhorar as características de suculência e maciez em hambúrgueres com baixo nível de gordura. O objetivo do presente estudo foi verificar o efeito da fécula de mandioca e da farinha de aveia sobre as características físicas, químicas e sensoriais de hambúrgueres de carne ovina com teor de gordura reduzido. Foram testadas 4 formulações à base de carne ovina limpa: testemunha sem gordura adicionada (F1, com 9,15% de gordura ovina adicionada (F2, sem gordura adicionada e 2% de fécula de mandioca (F3 e sem gordura adicionada e 2% de farinha de aveia (F4. Foram avaliados durante o cozimento: composição centesimal, rendimento, encolhimento e capacidade de retenção de água, força de cisalhamento, cor e análise sensorial dos hambúrgueres. Os produtos nos quais foram adicionados os substitutos de gordura (F3 e F4 apresentaram menor teor de gordura, antes e depois de cozidos, menor encolhimento, maior rendimento e capacidade de retenção de água do que os das formulações F1 e F2. A força de cisalhamento e a intensidade de vermelho (a* foram menores nos produtos aos quais foram adicionados os substitutos de gordura (F3 e F4 do que nos produtos sem substituição (F1 e F2. Não foram detectadas diferenças na aceitação global dos produtos com diferentes formulações. Desta forma, conclui-se que o uso de fécula de mandioca e farinha de aveia pode ser uma alternativa de substituição de gordura em produtos de carne ovina de baixo nível de gordura tipo hambúrguer.Several ingredients have been successfully tested as fat replacers in meat products maintaining desirable attributes like tenderness, juiciness and cooking yield. Cassava starch and oatmeal have been used to maintain good texture, juiciness and overall

  13. Identification of the bacterial community responsible for traditional fermentation during sour cassava starch, cachaça and minas cheese production using culture-independent 16s rRNA gene sequence analysis

    Science.gov (United States)

    Lacerda, Inayara C. A.; Gomes, Fátima C. O.; Borelli, Beatriz M.; Faria Jr., César L. L.; Franco, Gloria R.; Mourão, Marina M.; Morais, Paula B.; Rosa, Carlos A.

    2011-01-01

    We used a cultivation-independent, clone library-based 16S rRNA gene sequence analysis to identify bacterial communities present during traditional fermentation in sour cassava starch, cachaça and cheese production in Brazil. Partial 16S rRNA gene clone sequences from sour cassava starch samples collected on day five of the fermentation process indicated that Leuconostoc citreum was the most prevalent species, representing 47.6% of the clones. After 27 days of fermentation, clones (GenBank accession numbers GQ999786 and GQ999788) related to unculturable bacteria were the most prevalent, representing 43.8% of the clones from the bacterial community analyzed. The clone represented by the sequence GQ999786 was the most prevalent at the end of the fermentation period. The majority of clones obtained from cachaça samples during the fermentation of sugar cane juice were from the genus Lactobacillus. Lactobacillus nagelli was the most prevalent at the beginning of the fermentation process, representing 76.9% of the clones analyzed. After 21 days, Lactobacillus harbinensis was the most prevalent species, representing 75% of the total clones. At the end of the fermentation period, Lactobacillus buchneri was the most prevalent species, representing 57.9% of the total clones. In the Minas cheese samples, Lactococcus lactis was the most prevalent species after seven days of ripening. After 60 days of ripening, Streptococcus salivarius was the most prevalent species. Our data show that these three fermentation processes are conducted by a succession of bacterial species, of which lactic acid bacteria are the most prevalent. PMID:24031676

  14. New challenges in the cassava transformation in Nigeria and Ghana:

    OpenAIRE

    Nweke, Felix

    2004-01-01

    "This paper describes the dramatic cassava transformation that has taken place in Nigeria and Ghana over the past 50 years. From a rural subsistence crop, cassava has become a major cash crop sold in urban markets, a source of livestock feed, industrial starch and urban convenience foods. This paper documents the key factors driving the cassava transformation in Nigeria and Ghana. Differences in timing, promotional efforts and performance provide an instructive contrast which helps to identif...

  15. Producción de Dextrinas a partir de Almidón Nativo de Yuca por Ruta Seca en una Agroindustria Rural Dextrin Production from Cassava Native Starch by Dry Route in a Rural Agroindustry

    Directory of Open Access Journals (Sweden)

    Reinaldo J Velasco

    2008-01-01

    Full Text Available En una agroindustria rural se utilizó yuca variedad MCOL 1505 para obtener dextrinas por ruta seca, siguiendo técnicas propuestas a nivel de laboratorio y probadas en planta piloto. La concentración óptima del almidón fue 37.8 % (w/v y el pH final tuvo una media de 3.1. El presecado se realizó con aire entre 55 y 60 ºC con un flujo de 0.21 m³/s con un sistema de homogenización, durante 120 minutos para una humedad del 3 al 5 % de los pellets. Para la conversión a dextrina se utilizó un flujo de aire de 0,1 m³/s a 150 ºC, un sistema de homogenización, y el tiempo de conversión fue de 45 minutos. Se obtuvo dextrina de yuca de calidad similar a la dextrina comercial de almidón de maíz. Se comprobó a nivel industrial que las condiciones experimentales determinadas en el laboratorio continuaron siendo válidas a excepción de las operaciones de mezclado y secado.In a rural agricultural industry, cassava variety MCOL 1505 was used to obtain dextrin using a dry route developed in the laboratory and tested in a pilot plant. The optimum concentration of starch was 37.8 (w / v and the final pH had an average of 3.1. The pre-drying process was conducted with air between 55 and 60 °C at a flowrate of 0.21 m³/s with a homogenization system, during 120 minutes for pellets of 3 to 5% moisture. For the conversion of cassava to dextrin an airflow of 0.1 m³/s at 150 °C and a homogenization system were used, being the conversion time of 45 minutes. Cassava dextrin of quality similar to the commercial corn starch dextrin was obtained. It was found that experimental conditions determined in the laboratory continued to be valid at industrial level except for the mixing and drying operations.

  16. Qualidade microbiológica na obtenção de farinha e fécula de mandioca em unidades tradicionais e modelo Microbiological quality in the flour and starch cassava processing in traditional and model unit

    Directory of Open Access Journals (Sweden)

    Raquel Resende Dósea

    2010-02-01

    Full Text Available O objetivo deste trabalho foi avaliar a qualidade microbiológica de farinha e fécula durante as diferentes etapas do processamento de mandioca, em unidades tradicionais e em uma unidade modelo. Foram determinados índices de coliformes totais e termotolerantes, Bacillus cereus, Salmonela spp., bactérias e fungos nas farinhas e féculas. Não foram observadas presenças de B. cereus e Salmonella spp. na farinha e fécula de mandioca produzidas nas unidades estudadas. A incidência microbiana diminui com o avanço da etapa do processamento para obtenção de farinha e foi menor na unidade modelo. Após o processo de torra, a carga microbiana estava de acordo com os valores preconizados pela legislação brasileira, concluindo-se que essa etapa pode ser considerada como crítica na obtenção de farinha. Na obtenção de fécula, a carga microbiana nas unidades tradicionais são maiores que na modelo, e o aumento do número de extrações promove o aumento da incidência de microrganismos, sendo recomendadas apenas quatro extrações.The objective of this research was to evaluate microbiological contamination in the flour and starch during cassava processing in traditional and model units. The total and fecal coliforms indexes, Bacillus cereus, Salmonella, bacteria, yeast and fungi were determined. Bacillus cereus and Salmonella were not detected in any sample. The incidence of microorganisms decreased along the processing to obtain cassava flour, and is lower in model unit. After the roasting process, the microbial load was below the values established by the Brazilian legislation, and can be regarded as a critical step in obtaining cassava flour. Concerning starch production, the microbial load in the traditional units was higher than in the model units, and the increase of the extraction steps has promoted the growth of microorganisms. It's recommended the used of only 4 extractions.

  17. Visit to India to evaluate the use of hydrocyclones for water conservation and effluent reduction in the cassava starch and sago industry

    OpenAIRE

    Marder, R.C.

    1994-01-01

    As a follow up to laboratory work completed under the project A0305 (Process Improvements to Starch Products from Root and Tuber Crops) and a process audit of starch and sago production (Trim and Curran, 1993) a visit was undertaken to carry out a preliminary field test of a hydrocyclone unit and evaluate its potential for application in the sago and starch industry. The commissioning trials showed that the unit performed marginally better than predicted during laboratory tests. Solid recove...

  18. Comparison of three cyanogen assays for total cyanogens in cassava (Manihot esculenta Crantz)

    DEFF Research Database (Denmark)

    Saka, J.D.K.; Mhone, A.R.K.; Brimer, Leon

    1997-01-01

    The sensitivity and reproducibility of three methods for determining the total cyanogenic potential (CNp) of 7 fresh and processed cassava varieties were determined and compared. The total cyanogen content of fresh cassava roots and three cassava products (kondowole, makaka, and starch) were...... analysed by the acid hydrolysis, microdiffusion with solid state detection and Cooke's enzymatic assays. The total cyanogen contents of the cassava, obtained by the three methods were not significantly different (p

  19. Study on microstructure of the product of cassava starch interacted with collagen%木薯淀粉与胶原蛋白作用物的结构形态研究

    Institute of Scientific and Technical Information of China (English)

    琚长霄; 黄立新; 许世枫; 赵璧秋

    2011-01-01

    Polarization microscope,scanning electron microscopy(SEM),infrared spectrum(IR),raman spectroscopy,X-ray diffraction and DSC were used to study the properties of the pro-starch produced by cassava starch and collagen.The results showed that the granule structure and apearance were destroyed with the increasing protein content,there was an obvious appearance of ester carbonyl C=O stretching vibration peak at 1732cm-1 on the infrared spectra and 1742cm-1 on the raman spectra,an interaction occurred between protein and cassava starch molecules.X-ray diffraction patterns indicated that the crystal structure of the products was intact,DSC showed that the endothermic peaks of the products decreased and gradually became smaller in the experimental temperature range.%利用光学显微镜,扫描电子显微镜,红外光谱仪,拉曼光谱仪,X-射线衍射分析仪,DSC(差示扫描量热仪)等仪器对木薯淀粉与胶原蛋白作用得到的蛋白-淀粉作用物的颗粒表观形貌、淀粉基团、晶体结构以及热力学性质进行观察、测定与研究。研究表明,改性后的淀粉颗粒形貌和结构随着蛋白质含量的增加出现了不同程度的破坏和改变,在红外光谱1732cm-1处出现了酯羰基C=O的伸缩振动峰,拉曼光谱在1742cm-1出现酯羰基C=O的伸缩拉曼峰,蛋白与淀粉分子发生了交联的作用。X-射线衍射图谱显示作用物的晶体结构完好,DSC显示在测

  20. 絮凝法提取木薯黄浆废水中植物蛋白质的效果研究%The study of flocculation extracted starch of cassava yellow pulp wastewater

    Institute of Scientific and Technical Information of China (English)

    万思杰; 李小丽; 彭小玉

    2016-01-01

    文章采用混凝技术提取木薯黄浆废水中的植物蛋白质物质,实验通过选取最佳的混凝剂和助凝剂种类及其最佳用量,并研究 pH、沉淀时间对混凝效果的影响,为木薯黄浆废水的资源化利用提供科学依据。单因素实验结果表明:分别以1%的PAC、1%的氯化铁和1%的改性玉米淀粉处理木薯黄浆废水,三种絮凝剂的最佳投加量分别为0.133g/L、0.133g/L和0.05g/L,最佳絮凝pH分别为9、2和8,三种絮凝剂的沉淀时间均大于15min时处理效果较佳,此时木薯黄浆淀粉废水的浊度去除率均到达80%以上,COD去除率达到50%。复配实验结果表明:PAC与PAM的复配投加后,PAC投加量为0.02g/L,PAM投加量为0.002g/L,浊度去除率从80%左右上升至98.2%,COD去除率上升至51.8%,复配絮凝剂相比单一絮凝剂提取植物蛋白效果更好。%The purpose of this study is trying to use technology for cassava starch production coagulation pretreatment of wastewater, which includes selecting the best coagulant type, determine coagulant, the optimum coagulant dosage, pH studies on mixed coagulation effect for the comprehensive management of cassava starch wastewater to provide some design parameters. Experimental results that the single factor, 0.1%PAC and 1%ferric chloride dosage 0.133g/L, 1%modified corn starch dosage0.05g/L, ferric chloride optimum pH was 2, PAC and corn starch optimal pH were 9 and 8, the settling time process is effective when more than 15min. Through traditional flocculants in yellow cassava pulp wastewater to determine the cationic polyacrylamide (PAM) and aluminum chloride (PAC) compound used better. PAM and the PAM complex volume ratio is 10:1. PAC dosage can be reduced twice, turbidity removal efficiency rise to 98.2% from 80%, showing that not only enhances the compound flocculant flocculation effect, but also reduces the pharmaceutical dosage.

  1. Cassava Mutation Breeding: Current Status and Trends

    International Nuclear Information System (INIS)

    Cassava (Manihot esculenta Crantz) is an important energy source in the diets of millions of people in the tropical and subtropical regions of the world, especially the poor. Also its industrial uses are steadily growing for starch, animal feed and bio-ethanol. Although it has high economic and social relevance, few major scientific efforts have been made to improve the crop until the 1970s. With the goals and objectives of cassava improvement through breeding, different strategies have been developed during the last several decades, such as evaluation and selection of the local landraces, introduced germplasm (as clones or segregating F1 population), hybridization (including inbreeding by both recurrent back-cross schemes and double haploids (DH)), interspecific hybridization, polyploidy breeding, genetic transformation, use of molecular markers and mutation breeding. Induced mutation breeding on cassava has been explored in the last several decades with few published papers. Yet, the production of novel genotypes, such as high amylose and small granule mutants and mutants with tolerance to post harvest physiological deterioration (PPD), has been reported. These results suggest that mutagenesis could be an effective alternative for cassava breeding. However, many drawbacks still exist in cassava mutation breeding, such as the occurrence of chimeras. Validated and developing protocols for different biotechnologies, such as TILLING protocol, cassava genome sequencing and cassava somatic embryogenesis, will significantly ameliorate the drawbacks to traditional mutation breeding, and consequently aid the routine application of induced mutation in both cassava improvement and in gene discovery and elucidation. (author)

  2. Effect of starch types on properties of biodegradable polymer based on thermoplastic starch process by injection molding technique

    OpenAIRE

    Yossathorn Tanetrungroj; Jutarat Prachayawarakorn

    2015-01-01

    In this study effects of different starch types on the properties of biodegradable polymer based on thermoplastic starch (TPS) were investigated. Different types of starch containing different contents of amylose and amylopectin were used, i.e. cassava starch, mungbean starch, and arrowroot starch. The TPS polymers were compounded and shaped using an internal mixer and an injection molding machine, respectively. It was found that the amount of amylose and amylopectin contents on n...

  3. Morfología Superficial de Almidones Termoplásticos Agrio de Yuca y Nativo de Papa por Microscopía Óptica y de Fuerza Atómica Surface Morphology of Sour Cassava and Native Potato Thermoplastic Starches by Optical and Atomic Force Microscopy

    Directory of Open Access Journals (Sweden)

    Harold A Acosta

    2006-01-01

    Full Text Available Se ha evaluado la morfología superficial de almidones termoplásticos (TPS obtenidos de almidones agrio de yuca y nativo de papa, extruidos con tornillo simple, usando microscopía óptica de alta resolución (OM y de fuerza atómica (AFM. Muestras de almidones agrio de yuca y nativo de papa más glicerina, se procesaron a 120 ºC y 50 rpm, dando extruidos que se cortaron en láminas delgadas, que se observaron por OM y AFM (modo contacto intermitente. El almidón nativo de papa mostró grandes gránulos ovoides y el almidón agrio de yuca reveló el ataque enzimático debido a la fermentación natural. Los TPS mostraron superficies lisas y rugosas dependiendo de la forma y el tamaño del gránulo, de la fermentación natural y del contenido de plastificante. Los TPS nativo de papa exhibieron pocas superficies lisas por OM y alta rugosidad por AFM; lo contrario se presentó con el TPS agrio de yuca, debido a su fermentación natural previa. Estos resultados contribuyen a predecir y entender las propiedades microestructurales, mecánicas y texturales de los almidones termoplásticos.An evaluation was made of the surface morphology of thermoplastic starches (TPS from sour cassava and native potato, extruded with a single-screw extruder, using high-resolution optical microscopy (OM and atomic force microscopy (AFM. Samples of sour cassava starch and native potato starch and glycerine, were processed at 120(0C and 50 rpm, producing extrudates which were cut into thin films for observation by OM and AFM (intermittent contact mode. Native potato starch showed large ovoid granules, while sour cassava starch revealed enzyme attack due to natural fermentation. The TPS had smooth and rough surfaces, depending upon granule size and shape, starch fermentation, and plasticizer content. Native potato TPS presented few smooth surfaces by OM and high roughness by AFM. The opposite was observed with sour cassava TPS, which had experienced some previous natural

  4. Effect of thermal and chemical modifications on the mechanical and release properties of paracetamol tablet formulations containing corn, cassava and sweet potato starches as filler-binders

    Directory of Open Access Journals (Sweden)

    Mariam Vbamiunomhene Lawal

    2015-07-01

    Conclusions: Modification of the experimental starches improved the mechanical and release properties of directly compressed paracetamol tablet formulations. Thus, they can be developed for use as pharmaceutical excipients in specific formulations.

  5. Cassava Genetic Transformation and its Application in Breeding

    Institute of Scientific and Technical Information of China (English)

    Jia Liu; Qijie Zheng; Qiuxiang Ma; Kranthi Kumar Gadidasu; Peng Zhang

    2011-01-01

    As a major source of food, cassava (Manihot esculenta Crantz) is an important root crop in the tropics and subtropics of Africa and Latin America, and serves as raw material for the production of starches and bioethanol in tropical Asia. Cassava improvement through genetic engineering not only overcomes the high heterozygosity and serious trait separation that occurs in its traditional breeding, but also quickly achieves improved target traits. Since the first report on genetic transformation in cassava in 1996, the technology has gradually matured over almost 15 years of development and has overcome cassava genotype constraints, changing from mode cultivars to farmer-preferred ones.Significant progress has been made in terms of an increased resistance to pests and diseases, biofortification, and improved starch quality,building on the fundamental knowledge and technologies related to planting, nutrition, and the processing of this important food crop that has often been neglected. Therefore, cassava has great potential in food security and bioenergy development worldwide.

  6. Changes in physical properties of extruded sour cassava starch and quinoa flour blend snacks Mudanças nas propriedades físicas de snacks extrusados de misturas de polvilho azedo e farinha de quinoa

    Directory of Open Access Journals (Sweden)

    Lívia Giolo Taverna

    2012-12-01

    Full Text Available Given the broad acceptance of sour cassava starch biscuits in Brazil and the nutritional quality of quinoa flour, this study aimed to evaluate the effect of extrusion temperature, screw speed, moisture, and amount of quinoa flour on the physical properties of puffed snacks. Extrusion process was carried out using a single-screw extruder in a factorial central composite design with four factors. Effects of moisture and amount of quinoa flour on the expansion index and specific volume of snacks were observed. There was a pronounced increase in water solubility index of blends with the extrusion process with significant effects of all process parameters on the WSI. Higher water absorption index (WAI was observed under high temperature, low moisture, and lower quinoa flour amount. Temperature and amount of quinoa flour influenced the color of the snacks. A positive quadratic effect of quinoa flour on hardness of products was observed. Blends of sour cassava starch and quinoa flour have good potential for use as raw material in production of extruded snacks with good physical properties.Dada a ampla aceitação do biscoito de polvilho azedo no Brasil e a qualidade nutricional da farinha de quinoa, este trabalho objetivou avaliar o efeito da temperatura de extrusão, rotação da rosca, umidade e porcentagem de farinha de quinoa sobre as propriedades físicas de snacks expandidos. O processo foi realizado em extrusor monorrosca, seguindo o delineamento central composto rotacional para quatro fatores. Foi observado o efeito da umidade e da porcentagem de farinha de quinoa sobre o índice de expansão e volume específico. Houve um aumento pronunciado na solubilidade das misturas com o processo de extrusão, com efeitos significativos de todos os parâmetros de processo no ISA. Maior índice de absorção de água (IAA foi observado em alta temperatura, baixa umidade e menor porcentagem de farinha de quinoa. Temperatura e porcentagem de farinha de

  7. The effect of a non-starch polysaccharide-hydrolysing enzyme (Rovabio® Excel) on feed intake and body condition of sows during lactation and on progeny growth performance.

    Science.gov (United States)

    Walsh, M C; Geraert, P A; Maillard, R; Kluess, J; Lawlor, P G

    2012-10-01

    A total of 200 (Large White × Landrace) sows were used in a 39-day study to evaluate the effects of feeding a non-starch polysaccharide (NSP)-hydrolysing enzyme multicomplex (Rovabio(®) Excel) in conjunction with a high- or reduced nutrient-density diet during lactation on sow body condition, feed intake and progeny performance. Eight sows were selected each week for 25 weeks, blocked by parity and BW into groups of four, and within the block randomly assigned to one of the four treatments (n = 50/treatment). Treatments were: (1) LND: low energy (13.14 MJ of DE/kg), low CP (15%) diet; (2) LND + RE: LND with 50 mg/kg NSP-hydrolysing enzyme; (3) HND: high energy (14.5 MJ of DE/kg), high CP (16.5%) diet; and (4) HND + RE: HND with 50 mg/kg NSP-hydrolysing enzyme. Sows were fed treatment diets from day 109 of gestation until the day of subsequent service. Between weaning and re-service, Rovabio(®) Excel addition to LND diets resulted in an increase in energy intake; however, a reduction was observed when supplemented to the HND diet (P Excel increased feed and energy intake during week 3 (days 15 to 21) of lactation (P Excel had greater back-fat depth at weaning and service (P < 0.05); however, the magnitude of change in back-fat depth during lactation and from farrowing to service was not different between treatments. Feeding the HND diet increased energy intake before farrowing, throughout lactation and during the weaning to service interval (P < 0.01); however, overall, average daily feed intake tended to be reduced (P < 0.10). At service, sows fed the HND diet were heavier than sows fed the LND diet (P < 0.05); however, the magnitude of change in BW between treatments was not different. Feeding the HND diet to sows resulted in a tendency for heavier piglets at birth (P = 0.10) that tended to grow at a faster rate and be heavier at weaning than piglets from sows fed the LND diet (P = 0.06). These results indicate that NSP-degrading enzymes offer minimal benefit

  8. Characterization of starch nanoparticles

    Science.gov (United States)

    Szymońska, J.; Targosz-Korecka, M.; Krok, F.

    2009-01-01

    Nanomaterials already attract great interest because of their potential applications in technology, food science and medicine. Biomaterials are biodegradable and quite abundant in nature, so they are favoured over synthetic polymer based materials. Starch as a nontoxic, cheap and renewable raw material is particularly suitable for preparation of nanoparticles. In the paper, the structure and some physicochemical properties of potato and cassava starch particles of the size between 50 to 100 nm, obtained by mechanical treatment of native starch, were presented. We demonstrated, with the aim of the Scanning Electron Microscopy (SEM) and the non-contact Atomic Force Microscopy (nc-AFM), that the shape and dimensions of the obtained nanoparticles both potato and cassava starch fit the blocklets - previously proposed as basic structural features of native starch granules. This observation was supported by aqueous solubility and swelling power of the particles as well as their iodine binding capacity similar to those for amylopectin-type short branched polysaccharide species. Obtained results indicated that glycosidic bonds of the branch linkage points in the granule amorphous lamellae might be broken during the applied mechanical treatment. Thus the released amylopectin clusters could escape out of the granules. The starch nanoparticles, for their properties qualitatively different from those of native starch granules, could be utilized in new applications.

  9. Characterization of starch nanoparticles

    International Nuclear Information System (INIS)

    Nanomaterials already attract great interest because of their potential applications in technology, food science and medicine. Biomaterials are biodegradable and quite abundant in nature, so they are favoured over synthetic polymer based materials. Starch as a nontoxic, cheap and renewable raw material is particularly suitable for preparation of nanoparticles. In the paper, the structure and some physicochemical properties of potato and cassava starch particles of the size between 50 to 100 nm, obtained by mechanical treatment of native starch, were presented. We demonstrated, with the aim of the Scanning Electron Microscopy (SEM) and the non-contact Atomic Force Microscopy (nc-AFM), that the shape and dimensions of the obtained nanoparticles both potato and cassava starch fit the blocklets - previously proposed as basic structural features of native starch granules. This observation was supported by aqueous solubility and swelling power of the particles as well as their iodine binding capacity similar to those for amylopectin-type short branched polysaccharide species. Obtained results indicated that glycosidic bonds of the branch linkage points in the granule amorphous lamellae might be broken during the applied mechanical treatment. Thus the released amylopectin clusters could escape out of the granules. The starch nanoparticles, for their properties qualitatively different from those of native starch granules, could be utilized in new applications.

  10. Effects of sodium chloride and sodium sulfate on the cross-linking reaction of cassava starch%氯化钠及硫酸钠对木薯淀粉交联反应的影响

    Institute of Scientific and Technical Information of China (English)

    熊小雅; 叶为标; 高群玉

    2016-01-01

    The experiment was designed to determine the relationships between osmotic pressure and degree of substitution,and the viscosity characteristics of the starch samples. Brabender viscometer was used for the determination of cross–linked cassava starch that dealed with osmotic pressure. When sodium chloride was used as osmotic pressure enhancer in cross–linking reaction,with the increase of osmotic pressure,the initial gelatinization temperature increased,and the peak viscosity and the final viscosity decreased. As the osmotic pressure reached high,the retrogradation value and the breakdown value both tended to zero. When sodium sulfate was used instead of sodium chloride,as the osmotic pressure increased,the initial gelatinization temperature didn’t change significantly,the peak viscosity leveled off following decrease,the final viscosity increased(not significant)after decrease,the breakdown value was in contrast with the final viscosity,and the retrogradation decreased. The degree of crosslinking increased with the increase of osmotic pressure that produced by sodium chloride or sodium sulfate. In addition,we utilized polarizing microscope and FTIR to analyze the cross–linked cassava starch that dealed with osmotic pressure,and measured their transparency,shear resistance and retrogradation resistance,the results showed that the corresponding properties of the cross–linked starch changed.%旨在确定渗透压与交联取代度和所得淀粉糊黏度间的关系。应用Brabender连续黏度计对渗透压处理交联木薯淀粉进行了测定。当氯化钠作为交联反应渗透压促进剂时,随渗透压增大,所得淀粉样品的起始糊化温度增加,峰值黏度和最终黏度减小;高渗透压时,凝沉值和崩解值都趋于0。而硫酸钠作渗透压促进剂时,随渗透压的增大,起始糊化温度变化不明显,峰值黏度先下降后缓慢下降,最终黏度先减后增(增加不显著),崩解值先增

  11. Effect of addition of different hydrocolloids on pasting, thermal, and rheological properties of cassava starch Efeito da adição de diferentes hidrocoloides sobre as propriedades de pasta, térmicas e reológicas do amido de mandioca

    Directory of Open Access Journals (Sweden)

    Tatiana Dias Leite

    2012-09-01

    Full Text Available Starches and gums are hydrocolloids frequently used in food systems to provide proper texture, moisture, and water mobility. Starch-gum interaction in food systems can change the starch granule swelling and its gelatinization and rheological properties. In this study, the effect of the addition of xanthan gum (XG, sodium carboxymethyl cellulose (SCMC, and carrageenan (CAR at the concentrations of the 0.15, 0.25, 0.35 and 0.45% (w/v on the pasting, thermal, and rheological properties of cassava starch was studied. The swelling power (SP and the scanning electron microscopy (SEM of the starch gels were also evaluated. The results obtained showed that xanthan gum (XG had a strong interaction with the cassava starch penetrating between starch granules causing increase in pasting viscosities, SP, storage and loss (G', and G", respectively modulus and reduction in the setback of the starch; sodium carboxymethyl cellulose (SCMC greatly increased the pasting viscosities, the SP, and the storage and loss (G', and G", respectively modulus of the starch-mixtures, mainly due to its greater capacity to hold water and not due to the interaction with cassava starch. Carrageenan (CAR did not change any of the starch properties since there was no interaction between this gum and cassava starch at the concentrations used.Amidos e gomas são hidrocoloides frequentemente usados em sistemas alimentícios com a finalidade de fornecer textura, umidade e mobilidade de água. A interação amido-goma em sistemas alimentícios pode alterar o inchamento do grânulo de amido e as suas propriedades de gelatinização e reológicas. Neste trabalho, o efeito da adição de goma xantana (GX, carboximetilcelulose sódica (CMC e carragena (CAR nas concentrações de 0,15, 0,25, 0,35 e 0,45% (p/v sobre as propriedades de pasta, térmicas e reológicas do amido de mandioca foi estudado. O Poder de inchamento (PI e a Microscopia Eletrônica de Varredura (MEV dos géis de amido tamb

  12. Transcriptional response to petiole heat girdling in cassava.

    Science.gov (United States)

    Zhang, Yang; Ding, Zehong; Ma, Fangfang; Chauhan, Raj Deepika; Allen, Doug K; Brutnell, Thomas P; Wang, Wenquan; Peng, Ming; Li, Pinghua

    2015-01-01

    To examine the interactions of starch and sugar metabolism on photosynthesis in cassava, a heat-girdling treatment was applied to petioles of cassava leaves at the end of the light cycle to inhibit starch remobilization during the night. The inhibition of starch remobilization caused significant starch accumulation at the beginning of the light cycle, inhibited photosynthesis, and affected intracellular sugar levels. RNA-seq analysis of heat-treated and control plants revealed significantly decreased expression of genes related to photosynthesis, as well as N-metabolism and chlorophyll biosynthesis. However, expression of genes encoding TCA cycle enzymes and mitochondria electron transport components, and flavonoid biosynthetic pathway enzymes were induced. These studies reveal a dynamic transcriptional response to perturbation of sink demand in a single leaf, and provide useful information for understanding the regulations of cassava under sink or source limitation.

  13. Cassava biology and physiology.

    Science.gov (United States)

    El-Sharkawy, Mabrouk A

    2004-11-01

    Cassava or manioc (Manihot esculenta Crantz), a perennial shrub of the New World, currently is the sixth world food crop for more than 500 million people in tropical and sub-tropical Africa, Asia and Latin America. It is cultivated mainly by resource-limited small farmers for its starchy roots, which are used as human food either fresh when low in cyanogens or in many processed forms and products, mostly starch, flour, and for animal feed. Because of its inherent tolerance to stressful environments, where other food crops would fail, it is often considered a food-security source against famine, requiring minimal care. Under optimal environmental conditions, it compares favorably in production of energy with most other major staple food crops due to its high yield potential. Recent research at the Centro Internacional de Agricultura Tropical (CIAT) in Colombia has demonstrated the ability of cassava to assimilate carbon at very high rates under high levels of humidity, temperature and solar radiation,which correlates with productivity across all environments whether dry or humid. When grown on very poor soils under prolonged drought for more than 6 months, the crop reduce both its leaf canopy and transpiration water loss, but its attached leaves remain photosynthetically active, though at greatly reduced rates. The main physiological mechanism underlying such a remarkable tolerance to drought was rapid stomatal closure under both atmospheric and edaphic water stress, protecting the leaf against dehydration while the plant depletes available soil water slowly during long dry periods. This drought tolerance mechanism leads to high crop water use efficiency values. Although the cassava fine root system is sparse, compared to other crops, it can penetrate below 2 m soil,thus enabling the crop to exploit deep water if available. Leaves of cassava and wild Manihot possess elevated activities of the C4 enzyme PEP carboxylase but lack the leaf Kranz anatomy typical of C4

  14. Cassava biology and physiology.

    Science.gov (United States)

    El-Sharkawy, Mabrouk A

    2004-11-01

    Cassava or manioc (Manihot esculenta Crantz), a perennial shrub of the New World, currently is the sixth world food crop for more than 500 million people in tropical and sub-tropical Africa, Asia and Latin America. It is cultivated mainly by resource-limited small farmers for its starchy roots, which are used as human food either fresh when low in cyanogens or in many processed forms and products, mostly starch, flour, and for animal feed. Because of its inherent tolerance to stressful environments, where other food crops would fail, it is often considered a food-security source against famine, requiring minimal care. Under optimal environmental conditions, it compares favorably in production of energy with most other major staple food crops due to its high yield potential. Recent research at the Centro Internacional de Agricultura Tropical (CIAT) in Colombia has demonstrated the ability of cassava to assimilate carbon at very high rates under high levels of humidity, temperature and solar radiation,which correlates with productivity across all environments whether dry or humid. When grown on very poor soils under prolonged drought for more than 6 months, the crop reduce both its leaf canopy and transpiration water loss, but its attached leaves remain photosynthetically active, though at greatly reduced rates. The main physiological mechanism underlying such a remarkable tolerance to drought was rapid stomatal closure under both atmospheric and edaphic water stress, protecting the leaf against dehydration while the plant depletes available soil water slowly during long dry periods. This drought tolerance mechanism leads to high crop water use efficiency values. Although the cassava fine root system is sparse, compared to other crops, it can penetrate below 2 m soil,thus enabling the crop to exploit deep water if available. Leaves of cassava and wild Manihot possess elevated activities of the C4 enzyme PEP carboxylase but lack the leaf Kranz anatomy typical of C4

  15. A unigene catalogue of 5700 expressed genes in cassava.

    Science.gov (United States)

    Lopez, Camilo; Jorge, Véronique; Piégu, Benoît; Mba, Chickelu; Cortes, Diego; Restrepo, Silvia; Soto, Mauricio; Laudié, Michèle; Berger, Christel; Cooke, Richard; Delseny, Michel; Tohme, Joe; Verdier, Valérie

    2004-11-01

    Two economically important characters, starch content and cassava bacterial blight resistance, were targeted to generate a large collection of cassava ESTs. Two libraries were constructed from cassava root tissues of varieties with high and low starch contents. Other libraries were constructed from plant tissues challenged by the pathogen Xanthomonas axonopodis pv.manihotis. We report here the single pass sequencing of 11,954 cDNA clones from the 5' ends, including 111 from the 3' ends. Cluster analysis permitted the identification of a unigene set of 5,700 sequences. Sequence analyses permitted the assignment of a putative functional category for 37% of sequences whereas approximately 16% sequences did not show any significant similarity with other proteins present in the database and therefore can be considered as cassava specific genes. A group of genes belonging to a large multigene family was identified. We characterize a set of genes detected only in infected libraries putatively involved in the defense response to pathogen infection. By comparing two libraries obtained from cultivars contrasting in their starch content a group of genes associated to starch biosynthesis and differentially expressed was identified. This is the first large cassava EST resource developed today and publicly available thus making a significant contribution to genomic knowledge of cassava. PMID:15630618

  16. Structural characterization of magnetic cassava-starch microspheres and their application in adsorption of lysozyme%木薯淀粉磁性微球的结构表征及其对溶菌酶的吸附性能

    Institute of Scientific and Technical Information of China (English)

    蓝平; 何日梅; 封余贤; 李庭龙; 熊根; 韦金峦; 梁佩珠; 廖安平

    2016-01-01

    The magnetic cassava starch microspheres have been prepared using Fe3O4 and cassava starch as starting materials. Fourier transform infrared spectrum,X-ray diffraction,thermal analyzer, scanning electron microscope,laser granulometer,and magnetic balance were used to characterize the product. The adsorption behavior of lysozyme on these microspheres was studied. The influence of magnetic microsphere dosage,solution pH,adsorption temperature and time on the adsorption efficiency was evaluated by single factor experiments. The results showed that magnetic starch microspheres contain 19.71% of Fe3O4,withD50 (median diameter) of 15.40µm,and magnetic susceptibility of 1.571×10−3cm3/g . When the dosage of microspheres was 1.25g,with solution pH value of 10,adsorption temperature of 25℃,adsorption time of 80min,the best adsorption efficiency of lysozyme on the microsphere was 84.67%. Based on the correlation coefficientR2,the adsorption rate can be better described by pseudo-second-order kinetics(R2=0.99997) than by pseudo-first-order kinetics (R2=0.99174),and the particle diffusion model(R2=0.69996).%磁性微球是高分子材料与磁性物质通过一定作用复合而成的一类具有特殊功能的磁性高分子微球。以木薯淀粉为原材料,复合共沉淀法制备的改性磁流体Fe3O4,采用两步法(化学交联法)制备木薯淀粉磁性微球。利用傅里叶变换红外光谱仪、X射线衍射仪、同步热分析仪、扫描电镜、激光粒度仪、磁天平等对其性能及结构进行表征并研究其对溶菌酶的吸附行为。通过单因素法考察磁性微球用量、溶液pH值、吸附温度、吸附时间对吸附率的影响,并采用准一级动力学模型和准二级动力学模型研究其吸附动力学。结果表明:制备的木薯淀粉磁性微球Fe3O4含量为19.71%,D50(中位径)为15.40µm,磁化率为1.571×10−3cm3/g,形貌规整;在微球用量为1.25g,溶液pH=10,吸附温度为25

  17. Produção de snacks funcionais à base de farinha de soja e polvilho azedo Production of functional snacks from soybean flour and sour cassava starch

    Directory of Open Access Journals (Sweden)

    Magali Leonel

    2010-06-01

    Full Text Available Este trabalho teve por objetivo avaliar o efeito da temperatura de extrusão e da porcentagem de farinha de soja sobre a expansão (IE, o índice de absorção de água (IAA, o índice de solubilidade em água (ISA, a cor (L*, a* e b* e a dureza de biscoitos extrusados. O processo de extrusão seguiu o delineamento central composto rotacional para dois fatores, totalizando 11 tratamentos. Os resultados obtidos mostraram que a temperatura e a porcentagem de farinha de soja tiveram efeitos significativos sobre as propriedades físicas dos produtos. Nas condições intermediárias de temperatura e baixa porcentagem de farinha de soja (10%, é possível obter biscoitos funcionais de mandioca com elevada expansão, índices intermediários de absorção e solubilidade em água, cor clara e baixa dureza.This study aimed to evaluate the effect of the extrusion temperature and the percentage of soybean flour in mixes on the expansion index (EI, water absorption index (WAI, water solubility index(WSI; color (L *, a *, b * and hardness of extruded sour cassava snacks. The extrusion process followed the rotational central composite design for two factors, totalizing 11 treatments. The results showed that the extrusion temperature and percentage of soybean flour in mixes had significant effects on the physical properties of products. Under the conditions of intermediate temperature and low percentage of soybean meal is possible to obtain function cassava snacks with high expansion, intermediate index of absorption and solubility in water, light color and low hardness.

  18. Análisis Físico-Químico y Morfológico de Almidones de Ñame, Yuca y Papa y Determinación de la Viscosidad de las Pastas Physicochemical and Morphological Analyses of Yam, Cassava and Potato Starches and Determination of their Viscosity

    Directory of Open Access Journals (Sweden)

    Armando Alvis

    2008-01-01

    Full Text Available Se estudiaron las propiedades fisicoquímicas y la morfología y los viscoamilogramas de cuatro almidones nativos de ñame, tres de yuca y uno de papa, Previo a las determinaciones, las muestras fueron secadas hasta peso constante. El contenido de cenizas y amilosa, la temperatura de gelatinización y la viscosidad fue inferior en yuca; la grasa mostró diferencias entre yuca y papa; el índice de absorción de agua en ñame, papa y yuca, mostró diferencias significativas. En el índice de solubilidad en agua no se apreciaron diferencias significativas entre ñame y papa. La facilidad de cocción fue similar en ñame y papa; el incremento en la viscosidad de la pasta fue mayor en ñame y papa. Igualmente, se observaron diferencias en la forma y tamaño del gránulo. Estos cambios en las propiedades, la viscosidad y la morfología, pueden influir en la fabricación y producción de productos alimentarios y no alimentarios derivados de estos almidones.The physicochemical properties, morphology and the viscoamilogrames of yam, potato and cassava native starches were studied. Previous the determinations, the samples were dried up to constant weight. Ash and amylose content, gelatinization temperature and viscosity were lower in cassava; fat showed differences between cassava and potato; water absorption index in yam, potato and cassava showed significant differences. Cooking facility was similar in yam and potato; the increase in paste viscosity was greater in yam and potato. Also, it was observed differences in shape and size granule. These changes in properties, viscosity and morphology can influence the manufacture of food and non-food products derived from these starches.

  19. Functional properties of extruded nano composites based on cassava starch, polyvinyl alcohol and montmorillonite; Propriedades funcionais de nanocompositos extrusados de amido de mandioca, alcool polivinilico e montmorilonita

    Energy Technology Data Exchange (ETDEWEB)

    Debiagi, Flavia; Mali, Suzana [Departamento de Bioquimica e Biotecnologia, Universidade Estadual de Londrina, PR (Brazil)

    2011-07-01

    The objectives of this work were to produce expanded nano composites (foams) based on starch, PVA and sodium montmorillonite and characterize them according to their expansion index (EI), density, water absorption capacity (WSC), mechanical properties and X-ray diffraction. The nano composites were prepared in a single-screw extruder using different starch contents (97.6 - 55.2 g/100 g formulation), PVA (0 - 40 g/100 g formulation), unmodified nano clay - Closite - Na (0 - 4. 8 g/100 g formulation) and glycerol (20 g/100 g formulation) as plasticizer. The addition of montmorillonite and PVA resulted in an increase of EI and a decrease of density of the samples, and reduced WSC and increased the mechanical strength of the foams. Through the analysis of X-ray diffraction can be observed that the addition of montmorillonite led to production of intercalated nano composites in all samples. (author)

  20. Simultaneous saccharification and fermentation of cassava to succinic acid by Escherichia coli NZN111.

    Science.gov (United States)

    Chen, Cuixia; Ding, Shaopeng; Wang, Dezheng; Li, Zhimin; Ye, Qin

    2014-07-01

    In this study, the production of succinic acid from cassava starch and raw cassava instead of glucose by Escherichia coli NZN111 was investigated. During the two-stage fermentation, simultaneous saccharification and fermentation (SSF) was applied in the anaerobic stage. The results showed that both the productivity and specific productivity in the process conducted at 40°C were higher than those in the cultivation conducted at 37°C. The yield of succinic acid based on the amount of added starch reached the highest level 0.86 g/g and cassava starch was almost totally hydrolyzed in the SSF process. With the improved cell density, 127.13 g/L of succinic acid was obtained. When the liquefied crude cassava powder was used directly in SSF, 106.17 g/L of succinic acid was formed. The result showed that crude cassava powder could be another cheap raw material for succinic acid formation. PMID:24787322

  1. Hydrolysate of corn starch saccharified with a dual-enzyme system and the effect on the crystallization of itaconic acid when used in fermentation

    Institute of Scientific and Technical Information of China (English)

    Li Piwu; Chen Xiguang; Liu Jianjun; Wang Lingchong

    2008-01-01

    An improved process of hydrolysis of corn starch was adopted in the production of itaconic acid (IA), the aim was to decrease the unfermentable reducing sugar (RS) in the medium from the beginning of the fermentation and to increase the crystallization efficiency of IA from the fermentation broth.The glucose (GS) syrups saccharified by several combinations of glucoamylase and pullulanase were investigated and used as the carbohydrate source of the fermentation medium for the spore-initiated submerged fermentations experiments.Compared with the conventional process (with pullulanase controlled), the improved process decreased the RS residue in the fermentation broth from 3.01g/L to 1.35g/L and from 4.25g/L to 3.25g/L when the original RS of the medium were 100 and 120g/L, respectively.The crystallization efficiency of IA increased from 65% to 78.8% and from 69.58% to 82.81% with the original RS being 100 and 120g/L, respectively.

  2. Cloning and characterization of a tuberous root-specific promoter from cassava (Manihot esculenta Crantz)

    NARCIS (Netherlands)

    Koehorst-van Putten, H.J.J.; Wolters, A.M.A.; Pereira-Bertram, I.J.; Berg, H.; Krol, van der A.R.; Visser, R.G.F.

    2012-01-01

    In order to obtain a tuberous root-specific promoter to be used in the transformation of cassava, a 1,728 bp sequence containing the cassava granule-bound starch synthase (GBSSI) promoter was isolated. The sequence proved to contain light- and sugar-responsive cis elements. Part of this sequence (1,

  3. Promoting Cassava as an Industrial Crop in Ghana: Effects on Soil Fertility and Farming System Sustainability

    Directory of Open Access Journals (Sweden)

    S. Adjei-Nsiah

    2012-01-01

    Full Text Available Cassava is an important starchy staple crop in Ghana with per capita consumption of 152.9 kg/year. Besides being a staple food crop, cassava can be used as raw material for the production of industrial starch and ethanol. The potential of cassava as an industrial commercial crop has not been exploited to a large extent because of perceptions that cassava depletes soils. Recent finding from field studies in the forest/savannah transitional agroecological zone of Ghana indicates that when integrated in the cropping system as a form of rotation, cassava contributes significantly to maintenance of soil fertility, and thus large scale production of cassava for industrial use can contribute to poverty reduction in an environmentally responsive way. This paper discusses the role of cassava cultivation in soil fertility management and its implication for farming system sustainability and industrialization.

  4. The Effect of Different Sample Dispersion Temperatures on Cassava Amylose and Amylopectin,Total Starch Content Determination by Double Wavelength Spectrophotometric Method%不同样品分散温度对双波长比色法测定木薯直、支链淀粉比率及总淀粉含量的影响

    Institute of Scientific and Technical Information of China (English)

    黄惠芳; 罗燕春; 侯学文; 符海天; 苏文潘; 彭靖茹; 黎萍; 黄强

    2012-01-01

    In order to determine the amylose and amylopectin, total starch content of cassava roots by double wavelength spectrophotometric method. The effect of different sample dispersion temperatures on cassava amylose and amylopectin, total starch content by double wavelength spectrophotometric method were studied. The results were as follows: the percentage of amylose was the lowest when the sample dispersion temperature was 85℃, however the percentage of amylopectin was the highest, among the sample dispersion temperature used. When the sample dispersion temperature was 80℃, the determined total starch content was the highest. These results demonstrated that the effects of sample dispersion temperatures on the determination of amylose, amylopectin, total starch content were different.%为了采用双波长比色法研究木薯直、支链淀粉比率及总淀粉含量的测定方法,研究了不同样品分散温度对木薯淀粉直、支链淀粉比率及总淀粉含量的影响.结果表明:在试验温度70~100℃范围内,85℃时直链淀粉百分比率最低,相对应地,85℃时支链淀粉的百分比率最高.样品分散温度对鲜薯中总淀粉含量测定值有影响,其测定值在80℃时最高.由此可知,不同样品分散温度对木薯淀粉直、支链淀粉比率及总淀粉含量测定值有影响.

  5. Development Trend of Cassava Industry and Market Analysis in China%我国木薯产业的发展趋势与市场分析①

    Institute of Scientific and Technical Information of China (English)

    文玉萍

    2014-01-01

    Expatiating on domestic current progress in cassava planting, cassava starch (modified starch) and cassava alcohol, and prospects of their future development tendency.%对我国的木薯种植,木薯淀粉(变性淀粉),木薯酒精行业的发展现状进行阐述,展望其发展趋势。

  6. Enzyme Activities and Substrate Degradation by Fungal Isolates on Cassava Waste During Solid State Fermentation

    OpenAIRE

    Pothiraj, C.; Eyini, M.

    2007-01-01

    The growth and bioconversion potential of selected strains growing on cassava waste substrate during solid state fermentation were assessed. Rhizopus stolonifer showed the highest and the fastest utilization of starch and cellulose in the cassava waste substrate. It showed 70% starch utilization and 81% cellulose utilization within eight days. The release of reducing sugars indicating the substrate saccharification or degradation potential of the organisms reached the highest value of 406.5 m...

  7. Chemical, physical and morphometric properties of Peruvian carrot (Arracacia xanthorrhiza B.) starch.

    Science.gov (United States)

    Pérez, E E; Borneo, R; Melito, C G; Tovar, J

    1999-01-01

    Starch was isolated from Peruvian carrot (PC)--or arracacha--(Arraccacia xanthorrhiza B.) roots. Its chemical, physical, physicochemical and granular structural properties were compared to those of commercial cassava starch. Scanning electron microscopy revealed a granular size for PC starch ranging between 4 and 26 microns in diameter, with spherical and truncated-egg shapes. PC and cassava starches were similar regarding gross chemical composition and basic physical characteristics but differed in pasting properties, with PC starch showing lower breakdown and consistency indices. The two starches also showed different water absorption and solubility patterns.

  8. Cassava, yam, sweet potato and ñampi starch: functional properties and possible applications in the food industry. Harinas y almidones de yuca, ñame, camote y ñampí: propiedades funcionales y posibles aplicaciones en la industria alimentaria.

    Directory of Open Access Journals (Sweden)

    Pedro Vargas Aguilar

    2013-03-01

    Full Text Available A technical review was conducted to related physical and chemical properties of flours and starches from cassava, yams, taro and sweet potato. Amyloseamylopectin content, viscosity, nutritional value and fiber, were studied to relate them with starch functional properties. A relationship was obtained between amylose-amylopectin, viscosity and fiber content with the digestibility of those starches and the glycemic index values. The use of fermentation to enhance the nutritional value of these starches is known. Starch fermentation allows the production of gluten-free bread and energy drinks as an option to diversify products. It was also observed the relationship between the starch viscosity and the fat absorption in fried foods.Se realizó una revisión de las características fisicoquímicas de las harinas y almidones de yuca, ñame, ñampí y camote, tales como el contenido de amilosa-amilopectina, la viscosidad, el valor nutricional y la fibra, con el fin de relacionarlas con sus propiedades funcionales y técnico-funcionales. Se obtuvo una relación entre el contenido de amilosa-amilopectina, viscosidad y contenido de fibra en la digestibilidad de estos almidones y los valores de índice glicémico. Se encontró que es posible introducir modificaciones por medio de la fermentación para mejorar el valor funcional de estos almidones. La fermentación permite elaborar pan sin gluten y bebidas energéticas como nuevas opciones de productos. También se encontró que existe una relación entre la viscosidad de los almidones y la disminución de absorción de la grasa en frituras.

  9. Production of methane by co-digestion of cassava pulp with various concentrations of pig manure

    DEFF Research Database (Denmark)

    Panichnumsin, Pan; Nopharatana, Annop; Ahring, Birgitte Kiær;

    2010-01-01

    Cassava pulp is a major by-product produced in a cassava starch factory, containing 50-60% of starch (dry basis). Therefore, in this study we are considering its potential as a raw material substrate for the production of methane. To ensure sufficient amounts of nutrients for the anaerobic...... digestion process, the potential of co-digestion of cassava pulp (CP) with pig manure (PM) was further examined. The effect of the co-substrate mixture ratio was carried out in a semi-continuously fed stirred tank reactor (CSTR) operated under mesophilic condition (37 C) and at a constant OLR of 3.5 kg VS m...

  10. Promoting Cassava as an Industrial Crop in Ghana: Effects on Soil Fertility and Farming System Sustainability

    OpenAIRE

    Adjei-Nsiah, S.; Owuraku Sakyi-Dawson

    2012-01-01

    Cassava is an important starchy staple crop in Ghana with per capita consumption of 152.9 kg/year. Besides being a staple food crop, cassava can be used as raw material for the production of industrial starch and ethanol. The potential of cassava as an industrial commercial crop has not been exploited to a large extent because of perceptions that cassava depletes soils. Recent finding from field studies in the forest/savannah transitional agroecological zone of Ghana indicates that when integ...

  11. Analysis of heterogeneity of Copia-like retrotransposons in the genome of cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Gbadegesin, Micheal A; Beeching, John R

    2011-12-20

    Retrotransposons are ubiquitous in eukaryotic genomes and now proving to be useful genetic tools for genetic diversity and phylogenetic analyses, especially in plants. In order to assess the diversity of Ty1/Copia-like retrotransposons of cassava, we used PCR primers anchored on the conserved domains of reverse transcriptases (RTs) to amplify cassava Ty1/Copia-like RT. The PCR product was cloned and sequenced. Sequences analysis of the clones revealed the presence of 69 families of Ty1/Copia-like retrotransposon in the genome of cassava. Comparative analyses of the predicted amino acid sequences of these clones with those of other plants showed that retroelements of this class are very heterogeneous in cassava. Cassava is widely grown for its edible roots in the tropical and subtropical regions of the world. Cassava roots, though poor in protein, are rich in starch (makes up about 80% of the dry matter), vitamin C, carotenes, calcium and potassium. It has a great commercial importance as a source of starch and starch based products. Realizing the importance of cassava, it stands out as a crop to benefit from biotechnology development. Heterogeneity of Mecops (Manihot esculenta copia-like Retrotransposons) showed that they may be useful for genetic diversity and phylogenetic analyses of cassava germplasm.

  12. Thermal and pasting properties of cassava starch-dehydrated orange pulp blends Propriedades térmicas e de pasta de misturas de fécula de mandioca e polpa cítrica

    Directory of Open Access Journals (Sweden)

    Magali Leonel

    2011-06-01

    Full Text Available Instant mixtures are easy to prepare and frequently present functional appeals. A quality parameter for instant mixtures is their rheological behavior. This study aimed at evaluating the effects of extrusion parameters on the pasting properties of cassava (Manihot esculenta L. starch and dehydrated orange (Citrus sinensis (L. Osbeck pulp mixtures. The variable parameters were moisture of mixtures (12.5 to 19%, barrel temperature (40 to 90ºC and screw rotation (170 to 266 rpm. The extruded mixtures did not show gelatinization enthalpy. Moisture had the greatest effect on paste properties. The initial pasting viscosity (before heating of RVA (Rapid visco analyzer is the most relevant parameter to instant mixtures. The highest cold viscosity values were obtained when mixtures were extruded under high moisture and high screw speed. High moisture (19.5%, intermediate temperature (65ºC and screw speed (218 rpm led to extruded mixtures production with low component degradation.Misturas instantâneas apresentam-se como produtos de fácil preparo e muitas vezes com apelos funcionais. Um parâmetro de qualidade nestas misturas é o comportamento reológico. Avaliou-se o efeito de parâmetros de extrusão sobre as propriedades de pasta de misturas de fécula de mandioca (Manihot esculenta L. e polpa de laranja (Citrus sinensis (L. Osbeck desidratada. A umidade das misturas (12.5 a 19%, a temperatura de extrusão (40 a 90ºC e a rotação da rosca (170 a 266 rpm foram considerados parâmetros variáveis. As misturas extrusadas não apresentaram entalpia de gelatinização. A umidade foi o fator de maior efeito sobre as propriedades de pasta. A viscosidade inicial (antes do aquecimento no RVA (Rapid visco analyzer é um dos parâmetros mais importantes para misturas instantâneas. Nas condições de elevada umidade e rotação da rosca são observadas as maiores viscosidades a frio. Condições de elevada umidade das misturas (19,5%, temperatura (65ºC e

  13. Use of irradiation to extend shelf life of cassava tubers

    International Nuclear Information System (INIS)

    Fresh cassava tubers (manihot esculenta crantz) were gamma irradiated at 0, 0.2, 0.5 and 1.0 KGy doses using cobalt-60 source. A portion of the irradiated cassava tubers was stored at room temperature (25-30 degree C) and the rest was packed in polyethylene bags and stored in refrigerator (5 1 degree C). Samples were analyzed for moisture, crude protein, starch and fibers percentages. Rotting ratio and weight loss percentages were also determined. The results indicated that the irradiation with gamma-rays followed by refrigeration extended the shelf-life of cassava tubers being more than 21 days. The lowest value of weight loss of cassava tubers during storage was observed by gamma irradiation and cold storage. Moreover, the irradiation treatments had no effect on protein content of cassava tubers, while it decreased moisture, starch and fiber contents especially those subjected to 1 kGy. As for the interaction between gamma-irradiation doses and periods of storage the crude protein slightly increased while the moisture, starch and fibers showed a gradual decrease up to the end of storage period as compared to unirradiated ones. 4 tabs

  14. Modification of water absorption capacity of a plastic based on bean protein using gamma irradiated starches as additives

    Energy Technology Data Exchange (ETDEWEB)

    Koeber, E. [Facultad de Ingenieria, Grupo de Ingenieria Bioquimica, Universidad de Buenos Aires, Paseo Colon 850, 1063, Buenos Aires (Argentina); Gonzalez, M.E. [Comision Nacional Energia Atomica, Av. Del Libertador 8250, Buenos Aires (Argentina); Gavioli, N. [Facultad de Ingenieria, Grupo de Ingenieria Bioquimica, Universidad de Buenos Aires, Paseo Colon 850, 1063, Buenos Aires (Argentina); Salmoral, E.M. [Facultad de Ingenieria, Grupo de Ingenieria Bioquimica, Universidad de Buenos Aires, Paseo Colon 850, 1063, Buenos Aires (Argentina)]. E-mail: esalmor@fi.uba.ar

    2007-01-15

    Some properties of a bean protein-starch plastic were modified by irradiation of the starch. Two kinds of starch from bean and cassava were irradiated with doses until 50 kGy before their inclusion in the composite. Water absorption of the resultant product was reduced by 36% and 60% in materials containing bean and cassava starch, respectively. A large decline in the elongation is observed till 10 kGy in both materials, while tensile strength diminished by 11% in the cassava composite.

  15. Cassava Commercialization in Mozambique

    OpenAIRE

    Donovan, Cynthia; Haggblade, Steven; Salegua, Venancio Alexandre; Cuambe, Constantino; Mudema, Joao; Tomo, Alda

    2011-01-01

    Cassava supplies roughly 30% of all calories consumed in Mozambique, making it the country’s most important food security crop. Over the past several decades, growing urbanization and shifting demand patterns have led to growing opportunities for cassava processing and commercialization. This paper examines the commercial dynamics in Mozambique’s cassava value chain as well as the food security implications of growing cassava commercialization.

  16. Egg protein hydrolysates

    NARCIS (Netherlands)

    Amerongen, van A.; Beelen, M.J.C.; Wolbers, L.A.M.; Gilst, van W.H.; Buikema, J.H.; Nelissen, J.W.P.M.

    2009-01-01

    The present invention provides egg-protein hydrolysates with DPP-IV inhibitory activity which are particularly suited for the treatment of diabetes. Particularly advantageous is to use hydrolysate of lysozyme for the treatment of diabetes.

  17. Efeito de fibras vegetais nas propriedades de compósitos biodegradáveis de amido de mandioca produzidos via extrusão Effects of vegetal fibers on properties of cassava starch biodegradable composites produced by extrusion

    Directory of Open Access Journals (Sweden)

    Flávia Debiagi

    2010-12-01

    Full Text Available A preocupação com o volume de lixo tem gerado interesse no desenvolvimento de embalagens biodegradáveis capazes de substituir, ao menos em parte, os plásticos convencionais sintéticos, como é o caso das embalagens de poliestireno expandido (Isopor. Ojvetivou-se,neste trabalho caracterizar, quanto ao índice de expansão (IE, densidade, índice de absorção em água (IAA, índice de solubilidade em água (ISA e cor (coordenadas L*, a* e b*, compósitos biodegradáveis expandidos produzidos via extrusão, a partir da mistura de amido de mandioca, glicerol (plastificante e dois tipos de fibras vegetais. Os compósitos foram preparados em extrusora mono-rosca, com três diferentes teores de fibras de aveia ou de cana-de-açúcar (0, 5 e 10 g/100 g amido, dois teores de umidade (18 e 26% e teor fixo de glicerol (20g/100 g sólidos. A adição das fibras não afetou significativamente o IE, a densidade e o IAA, porém diminuiu o ISA dos materiais, o que é uma vantagem, favorecendo a utilização das fibras no reforço dos compósitos. A adição de fibras levou ao escurecimento das amostras, com decréscimo da luminosidade (L* e, ainda, ao aumento nos valores dos parâmetros de cor a* e b*. Este estudo é passo fundamental para produção em escala industrial dos compósitos, que necessitam de condições de processo que forneçam resultados reprodutíveis de expansão e capacidade de absorção e solubilidade em água, propriedades de grande importância nesses produtos.The concern with the volume of waste has generated interest in the development of biodegradable packaging able to replace, at least in part, the conventional synthetic plastics, such as packs of expanded polystyrene (Isopor. This study aimed to characterize the expansion index, density, the water absorption index (WAI, water solubility index (WSI and color (coordinates L*, a* and b* of expanded biodegradable composites produced by extrusion, from the mixture cassava starch

  18. Efeito do teor de água, amilose, amilopectina e grau de gelatinização no crescimento do biscoito de amido de mandioca obtido por fermentação natural Effect of the water, amylose, amylopectin contents and the degree of gelatinization on the sour cassava (Manihot sculenta, K. starch biscuit growth

    Directory of Open Access Journals (Sweden)

    Claudio Ernani MENDES DA SILVA

    1998-04-01

    Full Text Available O amido de mandioca, assim como o amido de araruta, modificado por fermentação natural, quando formulado com água, sal e gordura vegetal hidrogenada para produzir o biscoito de "polvilho azedo", tem a propriedade de se expandir durante a cocção, como se nessa formulação existisse um agente aerante. O produto final obtido, tem uma estrutura alveolar, crocante e de baixa densidade. Pouco se conhece a respeito do mecanismo que envolve essa expansão e sobre os fatores que interferem na mesma. No presente trabalho, investigamos a influência do teor de água, o efeito da pré-gelatinização do amido fermentado e a adição de amilose e de amilopectina no crescimento do biscoito. O tempo de formação do biscoito, demonstrou ser altamente dependente do teor de água presente na sua formulação. A gelatinização total do amido modificado por fermentação, parece destruir completamente suas propriedades de expansão, pois não foi observado crescimento do biscoito com uma formulação padrão contendo apenas amido totalmente gelatinizado. Biscoitos formulados com amilose ou amilopectina em substituição ao amido fermentado, apresentaram baixo grau de expansão quando comparados ao padrão.The sour cassava starch (and also ararut starch is unique in the ability to produce a biscuit (made of water, shortening and salt that oven springs during baking as if it has in its formulation a leavening agent. The final product has an alveolar structure, it is crocant and low density. The fators that control its growth are unknown. In this paper were investigated the effects of the water, pregelatinized sour cassava starch, amylose and amylopectin contents on the biscuit growth. It has been showed that the time of formation of the biscuit structure depends on the water formulation content. The complete gelatinization of this starch seems to destroy its unique property to grow with heat as if it had a leavening agent in its formulation. Biscuits made of

  19. 13CO2 breath test to measure the hydrolysis of various starch formulations in healthy subjects.

    OpenAIRE

    Hiele, M; Ghoos, Y.; RUTGEERTS, P; Vantrappen, G; de Buyser, K

    1990-01-01

    13CO2 starch breath test was used to study the effect of physicochemical characteristics of starch digestion. As starch is hydrolysed to glucose, which is subsequently oxidised to CO2, differences in 13CO2 excretion after ingestion of different starch products must be caused by differences in hydrolysis rate. To study the effect of the degree of chain branching, waxy starch, containing 98% amylopectin, was compared with high amylose starch, containing 30% amylopectin, and normal crystalline s...

  20. Characterization of an 18,166 EST dataset for cassava (Manihot esculenta Crantz) enriched for drought-responsive genes

    Science.gov (United States)

    Cassava (Manihot esculenta Crantz) is a staple food for over 600 million people in the tropics and subtropics and is increasingly used as an industrial crop for starch production. Cassava has a high growth rate under optimal conditions but also performs well in drought-prone areas and on marginal so...

  1. Process for producing cassava hydroxypropyl distarch phosphate and study of the properties

    Institute of Scientific and Technical Information of China (English)

    邵亚东; 王艳楠; 刘大伟; 刘晓成

    2014-01-01

    In the experiment, the nature cassava starch reacted with 1,2-epoxypropane and sodium trimetaphosphate under basic condition to producing hydroxypropyl distarch phosphate.At same time ,prepared to researching characteristics of the starch, including the substitution degree, gelatinization temperature and peak viscosity.

  2. Degradation of raw starch by a wild amylolytic strain of Lactobacillus plantarum

    OpenAIRE

    Giraud, Eric; Champailler, Alain; Raimbault, Maurice

    1994-01-01

    Lactobacillus plantarum A6, isolated from fermented cassava, can break down cassava raw starch that has not been subjected to preliminary physicochemical treatment. When the pH was kept at 6, the microorganism cultured in a bioreactor excreted a high α-amylase activity (60 U/ml). Synthesis of the enzyme occurred during the stationary phase and resulted in full hydrolysis of the cassava starch granules. This gave 41 g of lactic acid from 45 g of raw starch after 3 days of fermentation. Enzymat...

  3. CHARACTERISATION OF CASSAVA FIBRE FOR USE AS A BIOMATERIAL

    Directory of Open Access Journals (Sweden)

    Lois Larbie

    2012-07-01

    Full Text Available In this study we investigate the cytotoxicity of de-starched cassava fibre granules and fine powder using human peripheral blood mononuclear cells (PBMC and examine changes in the composition of Simulated Body Fluid (SBF resulting from immersion of cassava fibre samples. The purpose of the study was to characterise cassavafibre for possible biomaterial applications. Preliminary results indicate insignificant cytotoxic effects on PBMCs with cassava sample concentrations of 0.1g/ml, 0.025g/ml and 0.00625g/ml. Additionally there was little or no significant change in Na, K, Mg, Cl, Ca, Mn, and Cu concentrations upon immersion in SBF as observed over a one week period at a temperature of 37°C. These initial results suggest cassava fibre may be considered for biomaterial applications following more extensive characterisation.

  4. Physical properties of snacks made from cassava leaf flour

    Directory of Open Access Journals (Sweden)

    Adriana Cristina Ferrari

    2014-02-01

    Full Text Available The food industry is continually growing with new products becoming available every year. Extrusion combines a number of unit operations in one energy efficient rapid continuous process and can be used to produce a wide variety of snacks foods. The objective of this study was to evaluate the effect of extrusion temperature, screw speed, and amount of cassava leaf flour mixed with cassava starch on the physical properties of extruded snacks processed using a single screw extruder. A central composite rotational design, including three factors with 20 treatments, was used in the experimental design. Dependent variables included the expansion index, specific volume, color, water absorption index, and water solubility index. Among the parameters examined, the amount of cassava leaf flour and extrusion temperature showed significant effects on extruded snack characteristics. Mixtures containing 10% of cassava leaf flour extruded at 100°C and 255 rpm shows favorable levels of expansion, color, water absorption index, and water solubility index.

  5. Native starch in tablet formulations: properties on compaction.

    Science.gov (United States)

    Bos, C E; Bolhuis, G K; Van Doorne, H; Lerk, C F

    1987-10-16

    Maize, potato, rice and tapioca (cassava) starch were evaluated with respect to their properties on direct compression. Rice starch showed much better compactibility as compared to maize, potato and tapioca starch. Moreover, its binding capacity proved to be almost insensitive to mixing with magnesium stearate. This in contrast to the dramatic decrease in crushing strength of potato starch tablets containing the lubricant. The compactibility of the starches was found to be strongly affected by the equilibrium moisture content of the starches, which is dependent on the relative humidity of the atmosphere under which the powders were stored. All starches showed adequate capacity for water uptake to act as a disintegrant. Rice starch exhibited worst flowability, caused by its fine particle size as compared to the other starches. Granulation of rice starch changed it into a potential filler-binder in tablets prepared by direct compression.

  6. Production of a raw starch saccharifying amylase byBacillus alvei grown on different agricultural substrates.

    Science.gov (United States)

    Achi, O K; Nijoku-Obi, A N

    1992-03-01

    Maximum activity of the amylase ofBacillus alvei was attained after growth of the organism on sorghum starch. Rice, corn, yam, cassava and potato starch gave high enzyme activities as did soluble starch. Glucose, maltose and glycerol were less effective. Optimum conditions for both growth and enzyme production were pH 6.8 at 40°C.

  7. Produção de biscoitos extrusados de polvilho azedo com fibras: efeito de parâmetros operacionais sobre as propriedades físicas Production of snacks from sour cassava starch and fiber: effect of operational parameters on physical properties

    Directory of Open Access Journals (Sweden)

    Karina Fernandes de Camargo

    2008-09-01

    Full Text Available Neste trabalho buscou-se avaliar o efeito de parâmetros operacionais do processo de extrusão no desenvolvimento de biscoitos de polvilho com fibras, utilizando como matérias-primas o polvilho azedo e o farelo de mandioca. O processamento foi realizado em um extrusor mono-rosca, sendo considerados parâmetros variáveis: temperatura na 3ª zona de extrusão, umidade e porcentagem de fibras na mistura. Para analisar o efeito combinado das variáveis independentes nas características tecnológicas dos extrusados, utilizou-se o delineamento 'central composto rotacional' para três fatores. Os resultados obtidos mostraram efeitos significativos da umidade e porcentagem de fibras sobre o volume específico, sendo que a temperatura afetou os índices de solubilidade e absorção de água dos produtos extrusados. Condições de baixa temperatura (65 °C, baixa umidade (12% e baixo teor de fibras (The purpose of this work was to evaluate the effect of operational extrusion parameters on the production of cassava fiber snacks from sour cassava starch and cassava bagasse. Processing was carried out in a single-screw extruder, with temperature in the third extrusion zone, moisture and fiber percentage as independent variables. In order to evaluate the effect of the independent variables on technological characteristics of the snacks, a central composite design with three factors was used. The results showed significant effects of moisture and fiber percentage on specific volume, and extrusion temperature had effects on Water Solubility Index (WSI and Water Absorption Index (WAI. Products with good technological characteristics can be produced at low temperature (65 °C, low fiber (<4% and low moisture (12% conditions.

  8. Levels of replacing corn by cassava starch on performance and carcass characteristics of bulls finished in feedlot / Substituição do milho pelo resíduo da fecularia de mandioca no desempenho e nas características de carcaça de bovinos terminados em confinamento

    Directory of Open Access Journals (Sweden)

    Liandra Maria Abaker Bertipaglia

    2010-07-01

    Full Text Available This work was carried out to study the effects of replacing corn by different levels of cassava starch (0; 12.5; 22.8 and 32.7% on performance and carcass characteristics of bulls finished in feedlot. Thirtytwo crossbred bulls (½ Aberdeen Angus vs. ½ Nellore with 18 months old and 380 + 24 kg live weight were used in a completely randomized experimental design with four treatments and eight replications. The experiment was realized during 56 days with 14 days for adaptation. The complete diets [roughage (cottonseed hulls + concentrate (corn, soybean meal and cassava starch] were given at 8 am and at 4 pm to bulls. It was analyzed the initial weight (IW, final weight (FW, average daily gain (ADG, dry matter intake (DMI, feed conversion (FC, hot carcass dressing (HCD, fat thickness (FAT, Longissimus muscle area (LMA, leg length (LL and cushion thickness (CT. The IW, FW, ADG, FC, HCW, HCD, FT, LMA, LL and CT did not present difference (P > 0.05 among levels of replacing corn by cassava starch. The results obtained on performance and carcass traits using cassava starch by-products as a replacement for corn can be considered satisfactory.Objetivou-se com este trabalho avaliar o efeito do nível de substituição (0; 12,5; 22,8 e 32,7% do milho pelo resíduo de fecularia de mandioca sobre o desempenho e características de carcaça de bovinos em confinamento. Trinta e dois machos inteiros mestiços (½ Aberdeen Angus vs. ½ Nelore com 18 meses de idade e 380 + 24 kg de peso vivo foram utilizados em delineamento experimental inteiramente casualizado, com quatro tratamentos e oito repetições. O experimento foi desenvolvido durante 56 dias com 14 dias de adaptação. As rações completas [volumoso (casca de algodão + concentrado (milho, farelo de soja e resíduo desidratado de fecularia de mandioca] foram fornecidas às 8 h e 16 h aos animais. Foi analisado o peso inicial (PI, peso final (PF ganho médio diário (GMD, ingestão de matéria seca

  9. Properties of extruded xanthan-starch-clay nanocomposite films

    OpenAIRE

    Cristina de Melo; Patrícia Salomão Garcia; Maria Victória Eiras Grossmann; Fábio Yamashita; Luiz Henrique Dall'Antônia; Suzana Mali

    2011-01-01

    The aim of this work was to manufacture the biodegradable nanocomposite films by extrusion from different combinations of cassava starch, xanthan gum and nanoclays (sodium montmorillonite - MMT- Na) and to characterize them according to their microstructure, optical, mechanical and barrier properties. Films were manufactured from nine starch/xanthan/nanoclay combinations, containing glycerol as plasticizer. Scanning electron microscopy (SEM) of the starch-xanthan extruded films showed reticul...

  10. Raman Spectroscopic Profile of Ethanol Fermentation in High Gravity Cassava Starch Brewing%浓醪乙醇发酵的单细胞拉曼光谱表征

    Institute of Scientific and Technical Information of China (English)

    李自达; 赖钧灼; 廖威; 刘军贤; 王桂文

    2012-01-01

    应用激光镊子拉曼光谱技术收集500 L发酵罐中木薯淀粉浓醪乙醇发酵过程底物、产物及酵母单细胞的拉曼光谱,以期从单细胞水平为乙醇发酵提供新的认识.结果显示:1)拉曼光谱可以实时监测浓醪乙醇发酵过程底物与产物的变化;2)酵母细胞胞内物质的变化存在类似于产物变化的前发酵期、主发酵期和后发酵期3个阶段,但出现的时间要比产物变化晚约4 h;3)为适应浓醪发酵环境,酵母细胞的生理状态和胞内物质在不断地进行调整,随着环境乙醇浓度的升高,酵母细胞在胞内累积蛋白质和脂类物质,蛋白质二级结构逐渐变为以无规则卷曲为主;4)发酵后期,酵母细胞在胞内累积大量的嘌呤类物质,但细胞间含量存在异质性.上述结果表明,单细胞拉曼光谱技术提供了一种研究微生物发酵的新方法,可从新的角度获知乙醇发酵过程酵母细胞内外的变化信息.%Raman spectroscopy is used to characterize the process of ethanol fermentation and look into the Saccharomyces cerevisiae cells at single-cell level. The ethanol fermentation using high-concentration cassava starch as feedstock is processed in a 500 L fermentor and the Raman spectra of substrate, product and individual yeast cell are acquired by using laser tweezers Raman spectroscopy (LTRS). Major results are as follows: 1) Raman spectroscopy can monitor the dynamic changes of substrate and product during the ethanol fermentation; 2) the changes of intracellular components of yeast cells exhibit three stages, I. E., primary fermentation, main fermentation and later fermentation, which are similar to those of products, but there is a delay of about 4 hi 3) yeast cells amend its physiological state and intracellular compounds to adapt to the high osmotic stress at the initial stage and the high ethanol concentration at the later stage of fermentation. Random coiling dominates the secondary structure of

  11. Sugarcane starch: quantitative determination and characterization

    Directory of Open Access Journals (Sweden)

    Joelise de Alencar Figueira

    2011-09-01

    Full Text Available Starch is found in sugarcane as a storage polysaccharide. Starch concentrations vary widely depending on the country, variety, developmental stage, and growth conditions. The purpose of this study was to determine the starch content in different varieties of sugarcane, between May and November 2007, and some characteristics of sugarcane starch such as structure and granules size; gelatinization temperature; starch solution filterability; and susceptibility to glucoamylase, pullulanase, and commercial bacterial and fungal α-amylase enzymes. Susceptibility to debranching amylolytic isoamylase enzyme from Flavobacterium sp. was also tested. Sugarcane starch had spherical shape with a diameter of 1-3 µm. Sugarcane starch formed complexes with iodine, which showed greater absorption in the range of 540 to 620 nm. Sugarcane starch showed higher susceptibility to glucoamylase compared to that of waxy maize, cassava, and potato starch. Sugarcane starch also showed susceptibility to debranching amylolytic pullulanases similar to that of waxy rice starch. It also showed susceptibility to α-amylase from Bacillus subtilis, Bacillus licheniformis, and Aspergillus oryzae similar to that of the other tested starches producing glucose, maltose, maltotriose, maltotetraose, maltopentose and limit α- dextrin.

  12. Effect of starch types on properties of biodegradable polymer based on thermoplastic starch process by injection molding technique

    Directory of Open Access Journals (Sweden)

    Yossathorn Tanetrungroj

    2015-04-01

    Full Text Available In this study effects of different starch types on the properties of biodegradable polymer based on thermoplastic starch (TPS were investigated. Different types of starch containing different contents of amylose and amylopectin were used, i.e. cassava starch, mungbean starch, and arrowroot starch. The TPS polymers were compounded and shaped using an internal mixer and an injection molding machine, respectively. It was found that the amount of amylose and amylopectin contents on native starch influence the properties of the TPS polymer. A high amylose starch of TPMS led to higher strength, hardness, degree of crystallization than the high amylopectin starch of TPCS. In addition, function group analysis by Fourier transforms infrared spectrophotometer, water absorption, and biodegradation by soil burial test were also examined.

  13. Cassava Commercialization in Malawi

    OpenAIRE

    Kambewa, Emma

    2010-01-01

    Malawi continues to rely on maize for household food security. Policies to enhance food security continue to target maize production. Traditionally production and use of cassava was localized in lakeshore areas until the past two decades when maize production was increasingly affected by rainfall variability. Cassava as an alternate food crop has rapidly gained popularity and commercialization of the cassava sector is steadily taking off. Policy and institutional support to diversify the food...

  14. Starch films from a novel (Pachyrhizus ahipa) and conventional sources: Development and characterization

    International Nuclear Information System (INIS)

    Biodegradable films from ahipa, cassava and corn native starches were developed by casting method and their physicochemical, mechanical and barrier properties were analyzed taking into account the different starch botanical sources. Filmogenic suspensions were prepared; their rheological behaviors were studied and all of them exhibited film-forming ability. However, mechanical assays demonstrated that unplasticized films were too rigid, limiting their technological applications. Thus, 1.5% w/w of glycerol as plasticizer was added to filmogenic suspensions and film flexibility and extensibility were improved, this effect was more significant for ahipa and cassava starch films. Furthermore, thickness, moisture content and water solubility of the developed films were increased when plasticizer was incorporated. Glycerol addition reduced film water vapor permeability and the lowest reduction corresponded to cassava starch films due to the high viscosity of its filmogenic suspensions. Plasticized starch films resulted to be UV radiation barriers; ahipa starch films had the lowest light absorption capacity and higher transparency than cassava and corn starch films. Dynamic-mechanical analysis indicated that plasticized films were partially miscible systems exhibiting two relaxations, one attributed to the starch-rich phase and the other to the glycerol-rich one. Likewise, it could be demonstrated that glycerol exerted a major plasticizing effect on ahipa starch matrixes. Highlights: ► Ahipa, cassava and corn starch films were developed by casting method. ► Glycerol effect on film mechanical behavior was major for tuberous starch films. ► Ahipa starch films resulted to be more transparent with lower UV absorption capacity. ► Plasticized films were partially miscible systems: with a glycerol-rich and a starch-rich phase. ► Glycerol exerted a major plasticizing effect on ahipa starch films.

  15. Starch films from a novel (Pachyrhizus ahipa) and conventional sources: Development and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Olivia V., E-mail: ovlopez75@yahoo.com.ar; Garcia, Maria A.

    2012-10-01

    Biodegradable films from ahipa, cassava and corn native starches were developed by casting method and their physicochemical, mechanical and barrier properties were analyzed taking into account the different starch botanical sources. Filmogenic suspensions were prepared; their rheological behaviors were studied and all of them exhibited film-forming ability. However, mechanical assays demonstrated that unplasticized films were too rigid, limiting their technological applications. Thus, 1.5% w/w of glycerol as plasticizer was added to filmogenic suspensions and film flexibility and extensibility were improved, this effect was more significant for ahipa and cassava starch films. Furthermore, thickness, moisture content and water solubility of the developed films were increased when plasticizer was incorporated. Glycerol addition reduced film water vapor permeability and the lowest reduction corresponded to cassava starch films due to the high viscosity of its filmogenic suspensions. Plasticized starch films resulted to be UV radiation barriers; ahipa starch films had the lowest light absorption capacity and higher transparency than cassava and corn starch films. Dynamic-mechanical analysis indicated that plasticized films were partially miscible systems exhibiting two relaxations, one attributed to the starch-rich phase and the other to the glycerol-rich one. Likewise, it could be demonstrated that glycerol exerted a major plasticizing effect on ahipa starch matrixes. Highlights: Black-Right-Pointing-Pointer Ahipa, cassava and corn starch films were developed by casting method. Black-Right-Pointing-Pointer Glycerol effect on film mechanical behavior was major for tuberous starch films. Black-Right-Pointing-Pointer Ahipa starch films resulted to be more transparent with lower UV absorption capacity. Black-Right-Pointing-Pointer Plasticized films were partially miscible systems: with a glycerol-rich and a starch-rich phase. Black-Right-Pointing-Pointer Glycerol exerted

  16. Cassava root membrane proteome reveals activities during storage root maturation.

    Science.gov (United States)

    Naconsie, Maliwan; Lertpanyasampatha, Manassawe; Viboonjun, Unchera; Netrphan, Supatcharee; Kuwano, Masayoshi; Ogasawara, Naotake; Narangajavana, Jarunya

    2016-01-01

    Cassava (Manihot esculenta Crantz) is one of the most important crops of Thailand. Its storage roots are used as food, feed, starch production, and be the important source for biofuel and biodegradable plastic production. Despite the importance of cassava storage roots, little is known about the mechanisms involved in their formation. This present study has focused on comparison of the expression profiles of cassava root proteome at various developmental stages using two-dimensional gel electrophoresis and LC-MS/MS. Based on an anatomical study using Toluidine Blue, the secondary growth was confirmed to be essential during the development of cassava storage root. To investigate biochemical processes occurring during storage root maturation, soluble and membrane proteins were isolated from storage roots harvested from 3-, 6-, 9-, and 12-month-old cassava plants. The proteins with differential expression pattern were analysed and identified to be associated with 8 functional groups: protein folding and degradation, energy, metabolism, secondary metabolism, stress response, transport facilitation, cytoskeleton, and unclassified function. The expression profiling of membrane proteins revealed the proteins involved in protein folding and degradation, energy, and cell structure were highly expressed during early stages of development. Integration of these data along with the information available in genome and transcriptome databases is critical to expand knowledge obtained solely from the field of proteomics. Possible role of identified proteins were discussed in relation with the activities during storage root maturation in cassava.

  17. 圆红冬孢酵母利用生物乙醇废水-木薯粉水解液发酵产油%Lipid production by Rhodosporidium toruloides using bioethanol wastewater-cassava starch hydrolysates

    Institute of Scientific and Technical Information of China (English)

    周稳稳; 相会明; 刁红亮; 李永红

    2015-01-01

    [目的]获得能够高效降解生物乙醇废水化学需氧量(COD)的圆红冬孢酵母菌株,评估废水初始COD浓度对驯化菌株生长的影响,将木薯粉生产微生物油脂和高浓度有机废水降解过程整合,以生物乙醇废水为水源制备生物乙醇废水-木薯粉水解液培养基,明确产油效率高、生物乙醇废水COD降解率高的初始还原糖浓度.[方法]采用在高浓度的生物乙醇废水中进行多次驯化的方法,获得能够适应废水环境的圆红冬孢酵母菌株;采用双酶水解法对加入乙醇废水中的木薯粉进行水解;采用重量法监测生物量浓度变化,采用酸热法提取油脂,重铬酸钾法监测COD,DNS法测定废水还原糖浓度,凯氏定氮法测定总氮,钼酸铵比色法测定总磷. [结果]通过驯化筛选得到一株能耐受高浓度生物乙醇废水的优势菌株Rhodosporidium toruloides D5.以未稀释的废水为培养基,驯化菌株的最终生物量浓度和COD降解率分别为3.8 g/L和75.0%.采用生物乙醇废水-木薯粉水解液发酵时,控制初始还原糖浓度低于30 g/L时,生物量浓度和油脂浓度随初始还原糖浓度的升高而升高,均在120 h时达到最高COD降解率,初始还原糖浓度对达到的最大COD降解率无明显影响,废水N、P去除率分别达到99%和92%以上. [结论]在未经稀释的高浓度生物乙醇废水中可获得较高的生物量浓度;采用高浓度生物乙醇废水-木薯粉水解液培养基发酵产油,初始还原糖浓度为30g/L,可在保证高油脂产量的同时,实现废水COD的高效降解,有效回收利用废水中残余的N、P源,从而降低微生物油脂生产和废水处理成本,研究结果可为开发廉价微生物油脂生产技术提供有用的参考.

  18. Biorefinery approach for cassava-based industrial wastes: Current status and opportunities.

    Science.gov (United States)

    Zhang, Ming; Xie, Li; Yin, Zhixuan; Khanal, Samir Kumar; Zhou, Qi

    2016-09-01

    Cassava, an important food crop, has been extensively employed as raw materials for various agri-industries to produce starch, bioethanol and other biobased products/chemicals. These cassava-based industries also generate large quantities of wastes/residues, rich in organic matter and suspended solids, and pose significant environmental issues. Their complex biochemical composition with high organic content endows them with a great potential for bioconversion into value-added products via biorefinery thereby providing economic and environmental sustainability to cassava industries. This state-of-the-art review covers the source, composition and characteristics of cassava industrial wastes and residues, and their bioconversion into value-added products, mainly biofuels (ethanol and butanol), biogas, biosurfactant, organic acids and other valuable biochemicals among others. This paper also outlines future perspectives with respect to developing more effective and efficient bioconversion processes for converting the cassava wastes and residues into high-value products. PMID:27117291

  19. Synthesis of Rosin Acid Starch Catalyzed by Lipase

    Directory of Open Access Journals (Sweden)

    Rihui Lin

    2014-01-01

    Full Text Available Rosin, an abundant raw material from pine trees, was used as a starting material directly for the synthesis of rosin acid starch. The esterification reaction was catalyzed by lipase (Novozym 435 under mild conditions. Based on single factor experimentation, the optimal esterification conditions were obtained as follows: rosin acid/anhydrous glucose unit in the molar ratio 2 : 1, reaction time 4 h at 45°C, and 15% of lipase dosage. The degree of substitution (DS reaches 0.098. Product from esterification of cassava starch with rosin acid was confirmed by FTIR spectroscopy and iodine coloration analysis. Scanning electron microscopy and X-ray diffraction analysis showed that the morphology and crystallinity of the cassava starch were largely destroyed. Thermogravimetric analysis indicated that thermal stability of rosin acid starch decreased compared with native starch.

  20. Structural characterization of Peruvian carrot (Arracacia xanthorrhiza) starch and the effect of annealing on its semicrystalline structure.

    Science.gov (United States)

    Rocha, Thais S; Cunha, Verena A G; Jane, Jay-Lin; Franco, Celia M L

    2011-04-27

    Structural characteristics of native and annealed Peruvian carrot (Arracacia xanthorrhiza) starches were determined and compared to those of cassava and potato starches. Peruvian carrot starch presented round and irregular shaped granules, low amylose content and B-type X-ray pattern. Amylopectin of this starch contained a large proportion of long (DP > 37) and short (DP 6-12) branched chains. These last ones may contribute to its low gelatinization temperature. After annealing, the gelatinization temperatures of all starches increased, but the ΔH and the crystallinity increased only in Peruvian carrot and potato starches. The annealing process promoted a higher exposure of Peruvian carrot amylose molecules, which were more quickly attacked by enzymes, whereas amylopectin molecules became more resistant to hydrolysis. Peruvian carrot starch had structural characteristics that differed from those of cassava and potato starches. Annealing affected the semicrystalline structure of this starch, enhancing its crystallinity, mainly due to a better interaction between amylopectin chains.

  1. Starch poisoning

    Science.gov (United States)

    Cooking starch poisoning; Laundry starch poisoning ... Cooking and laundry starch are both made from vegetable products, most commonly: Corn Potatoes Rice Wheat Both are usually considered nonpoisonous (nontoxic), but ...

  2. Direct ethanol production from cassava pulp using a surface-engineered yeast strain co-displaying two amylases, two cellulases, and {beta}-glucosidase

    Energy Technology Data Exchange (ETDEWEB)

    Apiwatanapiwat, Waraporn; Rugthaworn, Prapassorn [Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki (Japan). Post-Harvest Science and Technology Div.; Kasetsart Univ., Bangkok (Thailand). Nanotechnology and Biotechnology Div.; Murata, Yoshinori; Kosugi, Akihiko; Arai, Takamitsu; Mori, Yutaka [Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki (Japan). Post-Harvest Science and Technology Div.; Yamada, Ryosuke; Kondo, Akihiko [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering

    2011-04-15

    In order to develop a method for producing fuel ethanol from cassava pulp using cell surface engineering (arming) technology, an arming yeast co-displaying {alpha}-amylase ({alpha}-AM), glucoamylase, endoglucanase, cellobiohydrase, and {beta}-glucosidase on the surface of the yeast cells was constructed. The novel yeast strain, possessing the activities of all enzymes, was able to produce ethanol directly from soluble starch, barley {beta}-glucan, and acid-treated Avicel. Cassava is a major crop in Southeast Asia and used mainly for starch production. In the starch manufacturing process, large amounts of solid wastes, called cassava pulp, are produced. The major components of cassava pulp are starch (approximately 60%) and cellulose fiber (approximately 30%). We attempted simultaneous saccharification and ethanol fermentation of cassava pulp with this arming yeast. During fermentation, ethanol concentration increased as the starch and cellulose fiber substrates contained in the cassava pulp decreased. The results clearly showed that the arming yeast was able to produce ethanol directly from cassava pulp without addition of any hydrolytic enzymes. (orig.)

  3. Effect of Starch Sources on the Release Rates of Herbicides Encapsulated

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effects of starch sources on the behaviors of starch matrices and on the rates of herbicides released from the matrices were studied for slow release. The starches considered include native corn starch, wheat starch, potato starch and cassava starch. The matrices were prepared through encapsulating 2,4-dichlorophenoxyacetic or 2,4,5-trichlorophenoxyacetic acids as model herbicides with hot-gelatinized starch pastes. The encapsulation was evaluated in terms of herbicide content, swellability, encapsulation efficiency, and release rate. The results show that starch sources play an important role on the matrix behaviors and on release rates. The rate of 2,4-D released follows the order: wheat starch < potato starch < corn starch < cassava starch. And for the rate of 2,4,5-T, this order is nearly the same only with an exception that the late two kinds of starch are similar. It is also demonstrated that herbicides with different water solubility show different release rates, no matter what type of starch is used as the matrices.

  4. Cassava as a food.

    Science.gov (United States)

    Okezie, B O; Kosikowski, F V

    1982-01-01

    This review has attempted to examine information pertaining to the role of cassava (Manihot esculenta) as a major food source for a large part of the world population, particularly the countries of South America, Africa, and Asia, where it is primarily a major source of energy for 300 to 500 million people. Its cultivation, usually on small farms with little technology, is estimated to cover on an annual basis about 11 million hectares providing about 105 million tons, more than half of which is consumed by humans. The importance of cassava as an energy source can be seen by its growing demand in the European economic community countries where it forms up to 60% of the balanced diets for swine. Cassava is one of the crops that converts the greatest amount of solar energy into soluble carbohydrates per unit of area, thus 1 kg of moisture-free cassava meal may yield up to about 3750 kcal which would mean that a yearly production of 15 tons of cassava meal per hectare would yield some 56 million kcal. The major limitations of cassava as food appear to be its poor protein content and quality and the rapid post harvest deterioration of its roots which usually prevents their storage in the fresh state for more than a few days. However, in addition to its use for culinary purposes, cassava finds application in industrial products such as an adhesive for laundry purposes, for manufacturing paper, alcohol, butanol, dextrin, adhesive tape, textile sizing, and glue.

  5. Study on Preparation of Cross-Linked Cassava Starch Octenyl Succinate by the Mothod of Extrusion and Structure Characterization%挤压法制备交联辛烯基琥珀酸木薯淀粉酯工艺与结构表征

    Institute of Scientific and Technical Information of China (English)

    李彬; 王金鹏; 谢正军; 徐学明; 田耀旗; 金征宇

    2012-01-01

    The preparation of cassava cross-linked starch octenyl succinate by the mothod of extrusion was studied in this manuscript. The effect of the content of sodium trimetaphosphate. sodium hydroxide,moisture,reaction temperature and screwing speed on the emulsifying capacity were carefully investigated by single factor experiment. The optimum conditions of cassava cross-linked starch octenyl succinate preparation were- 1.0% sodium trimetaphosphate,0. 6 % sodium hydroxide,moisture 35 %,barrel temperature 120 ℃,and screwing speed 110 r/min. the emulsifying capacity of the product reached at 58. 56 %. The structure of the product was determined by means of Fourier transform infrared spectroscopy(FT-IR),scanning e-lectron microscopy(SEM) and X-ray diffraction(XRD).%采用挤压法研究了交联辛烯基琥珀酸木薯淀粉酯的工艺.探讨三偏磷酸钠、氢氧化钠、水分质量分数,以及出料温度和螺杆转速对交联淀粉酯乳化能力的影响,并对影响因素进行了正交优化.结果表明,在三偏磷酸钠质量分数1.0%,氢氧化钠质量分数0.6%,水分质量分数35%,出料温度120℃,螺杆转速110 r/min的反应条件下,制备得到的交联辛烯基琥珀酸木薯淀粉酯的乳化能力可以达到58.56%.同时,采用红外光谱、电镜扫描和X射线衍射等手段对产物进行了结构分析和表征.

  6. MICROMORPHOLOGICAL STUDIES OF STARCH GRANULES IN SELECTED PROCESSED INDIGENOUS FLOUR OF SOUTH WESTERN NIGERIA

    Directory of Open Access Journals (Sweden)

    Adeniyi A. JAYEOLA

    2013-06-01

    Full Text Available Starch granules of yam stem tubers, plantain fruits and cassava root tubers were studied using the light microscope and then compared. Yam and plantain, both monocotyledons, had morphologically similar granules between locations, being mostly oval in shape while the granules of cassava, a dicot, were predominantly globular but varied between locations. Differences in processing methods between locations might be responsible for the observed variation in cassava granules. There is a suggestion that starch granule morphology might follow lineages in a broad sense. The unique micromorphology of cassava starch granule could make it easily detectable when adulterated, substituted or contaminated with yam or plantain granules and this could provide a cost effective clue in forensic determination.

  7. Effect of enzymatic hydrolysis on some physicochemical properties of root and tuber granular starches Efeito da hidrólise enzimática sobre algumas propriedades físico-químicas de amidos de raízes e tubérculos

    OpenAIRE

    Thaís de Souza Rocha; Ana Paula de Almeida Carneiro; Celia Maria Landi Franco

    2010-01-01

    Enzymatic hydrolysis of granular starch is an important tool to provide information about granule structure. Cassava, sweet potato, Peruvian carrot, and potato starches were hydrolyzed by bacterial α-amylase at 37 °C for 48 hours, and the physicochemical properties of the residues from hydrolysis were determined. Cassava starch was the most susceptible to enzyme displaying 20.9% of hydrolysis, whereas potato starch was the most resistant with 5.9%. The granule average size varied from 10...

  8. Characterization of chestnut (Castanea sativa, mill) starch for industrial utilization

    OpenAIRE

    Demiate Ivo Mottin; Oetterer Marília; Wosiacki Gilvan

    2001-01-01

    Studies were conducted to characterize the chestnut and its starch. Chemical composition of the chestnuts showed high level of starch. Moisture level in the raw nuts was around 50g/100g in wet basis and starch content, around 80g/100g in dry basis; other nut flour components were protein (5.58 g/100g), lipid (5.39 g/100g), crude fiber (2.34 g/100g) and ash (2.14 g/100g). Starch fraction was chemically characterized in order to identify the granule quality as compared with those of cassava and...

  9. Comparison Analysis of Starch and Protein Expression Profiles on Cassava Tuberous Rootscv. SC8 and Its Tetraploid%华南8号木薯及其四倍体块根淀粉及蛋白表达谱的差异分析

    Institute of Scientific and Technical Information of China (English)

    安飞飞; 陈松笔; 李庚虎; 周锴; 李开绵

    2015-01-01

    [Objective]The aim of the study was to better understand the change of starch content, starch structure and its proteins regulatory mechanisms of cassava tuberous roots of diploid and its tetraploid.[Method]Tuberous roots of 10 months after planting were used as the materials, starch content was measured by weight in air and water, the proportion of amylose and amylopectin was determined by spectrophotometry, Excel 2013 and DPS v7.05 statistical software were used to analyze the data, the significant difference was determined by using Duncan method, the size, shape and number of amyloplast were observed by scanning electron microscopy, Western blot was used to verify some enzymes involved in starch synthesis and degradation, roots proteins of cassava tetraploid and diploid genotypes were excised and purified from 2D gels, Delta 2D software were used to analyze the different proteins with more than 2.0 fold changes and assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-TOF-MS/MS) were used to identify them, and the proteins were classified according to their functions combined with KEGG database.[Result]After chromosome doubling in tetraploid cassava, dry matter content, starch content and fresh roots weight were significantly decreased by 12.18%, 11.41%, and 35.34%, respectively. No significant difference was observed in amylase and amylopectin proportion. No significant difference in amyloplast morphology, mainly spherical, irregular sphere and ellipsoid also exist, the size was uniform, while the loose degree of amyloplast and space gap were increased, the number was decreased. The level of sucrose phosphate synthase (SPS) significantly decreased,β-amylase expression was increased, while the level of granule bound starch synthase I (GBSSI) was not changed. Twenty differential expressed protein spots were showed and analyzed by software, including 2 up-regulated spots and 18 down-regulated spots, 19 were successfully matched in

  10. Optimization of enzymatic hydrolysis of cassava to obtain fermentable sugars

    Institute of Scientific and Technical Information of China (English)

    Renata M. COLLARES; Luiza V. S. MIKLASEVICIUS; Mariana M. BASSACO; Nina P. G. SALAU; Marcio A. MAZUTTI; Dilson A. BISOGNIN; Lisiane M. TERRA

    2012-01-01

    This work evaluates the enzymatic hydrolysis of starch from cassava using pectinase,α-amylase,and amyloglucosidase.A central composite rotational design (CCRD) was carried out to evaluate the effects of amyloglucosidase,pectinase,reaction time,and solid to liquid ratio.All the experiments were carried out in a bioreactor with working volume of 2 L.Approximately 98% efficiency hydrolysis was obtained,resulting in a concentration of total reducing sugar released of 160 g/L.It was concluded that pectinase improved the hydrolysis of starch from cassava.Reaction time was found to be significant until 7 h of reaction.A solid to liquid ratio of 1.0 was considered suitable for hydrolysis of starch from cassava.Amyloglucosidase was a significant variable in the process:after its addition to the reaction media,a 30%-50% increase in the amount of total reducing sugar released was observed.At optimal conditions the maximum productivity obtained was 22.9 g/(L·h).

  11. THERMAL ANALYSIS, RHEOLOGY, X-RAY DIFFRACTOMETRY AND ATOMIC FORCE MICROSCOPY IN THE EVALUATION OF BINARY MIXTURES OF “STARCH-HYDROCOLLOIDS”

    OpenAIRE

    Crislaine Alberton; Tiago André Denck Colman; Juliane Alves de Souza; Cristina Soltovski de Oliveira; Marina Morena Pereira Andrade; Egon Schnitzler

    2014-01-01

    Starch is arguably the most investigated biopolymer in the world and the cassava starch that is extracted from Manihot esculenta Crantz, represents an important vegetal crop in tropical countries, where its roots and derivatives serve as food and a source of energy. The main composition of these roots is 70-80% water, 16-24% starch and small quantities (

  12. The effect of chemical treatments on the pH & microbial flora of cassava residues during storage

    OpenAIRE

    Thaísa Anders Carvalho Souza; Manoel Soares Júnior; Maria Raquel Hidalgo Campos; Thaynara Stella Carvalho Souza; Lívia Cunha Bandeira

    2013-01-01

    Cassava starch factories produce residues that can be commercialized as food ingredients. The objective of this study was to evaluate the microbiological safety of cassava peel and bagasse during storage, with and without chemical treatment. The bagasse was acidified with lactic acid, and the peel was immersed in a sodium hypochlorite solution. The microbiological analyses were carried out for 72 h after harvest. All of the samples showed the absence of pathogenic microorganisms, and the acid...

  13. Effect of Cassava Starch Anaerobic Fermentation Liquid on Pumpkin Growth, Yield and Fruit Quality%木薯淀粉厌氧发酵液对南瓜生长发育、产量及果实品质的影响

    Institute of Scientific and Technical Information of China (English)

    邓英毅; 陈群; 黄影花; 雷雪娇; 禤为翔; 韦仕飞; 韦思羽; 韦民政; 叶亦心; 郑虚; 张艺超; 莫干辉; 李韦柳; 张新宇; 王向导

    2016-01-01

    In order to ascertain the new resource utilizating way of cassava starch waste for environmental protection,this paper studied the effect of cassava starch anaerobic fermentation liquid (CSAFL)on pumpkin growth,yield and fruit quality,taking ‘Mibennangua’ as experimental material.The results showed that applying CSAFL could significantly promote the vegetative and reproductive growth,increase pumpkin yield and improve its fruit quality. Using CSAFL could also remarkably promote the growth of pumpkin main stem and leaves,increase leaf chlorophyll content. Besides,its fruit setting number per single plant,single fruit weight and yield were higher than that of the contrast by over 50%. Its fruit size,fruit shape index,contents of soluble solid,soluble sugar,soluble protein,starch and VC were significantly or very significantly increased than that of the contrast.Therefore,CSAFL can be used as additional fertilizer in pumpkin production,so as to realize the dual purposes of turning waste into wealth,and improving pumpkin yield and quality.%为了探明木薯淀粉废液的环保资源化利用新路子,以蜜本南瓜为试验材料,开展了木薯淀粉厌氧发酵液对南瓜生长发育、产量和果实品质的影响研究。结果表明,施用木薯淀粉厌氧发酵液能显著促进南瓜植株的营养生长和生殖生长,提高产量并改善果实的品质。施用木薯淀粉厌氧发酵液能显著促进植株主蔓和叶片的生长,增加叶片叶绿素含量,单株结瓜数、单瓜质量和产量均比常规施肥对照提高50%以上,其果实大小、果形指数、可溶性固形物、可溶性糖、可溶性蛋白、淀粉含量和VC含量也比对照显著或极显著提高。木薯淀粉厌氧发酵液可作为追肥在南瓜生产中应用,达到变废为宝、提高南瓜产量和品质的双重目的。

  14. Application of thermophilic enzymes and water jet system to cassava pulp.

    Science.gov (United States)

    Chaikaew, Siriporn; Maeno, Yuka; Visessanguan, Wonnop; Ogura, Kota; Sugino, Gaku; Lee, Seung-Hwan; Ishikawa, Kazuhiko

    2012-12-01

    Co-production of fermentable sugars and nanofibrillated cellulose from cassava pulp was achieved by the combination of thermophilic enzymes (endoglucanase, β-glucosidase, and α-amylase) and a new atomization system (Star Burst System; SBS), which employs opposing water jets. The SBS represents a key technology for providing cellulose nanofibers and improving the enzymatic saccharification of cassava pulp. Depending on the enzymes used, the production of glucose from cassava pulp treated with the SBS was 1.2- to 2.5-fold higher than that from pulp not treated with the SBS. Nanofibrillated cellulose with the gel-like property in suspension was produced (yield was over 90%) by α-amylase treatment, which completely released trapped starch granules from the fibrous cell wall structure of cassava pulp pretreated with the SBS. The SBS provides an environmentally low-impact pretreatment system for processing biomass material into value-added products. PMID:23073093

  15. The effect of chemical treatments on the pH & microbial flora of cassava residues during storage

    Directory of Open Access Journals (Sweden)

    Thaísa Anders Carvalho Souza

    2013-09-01

    Full Text Available Cassava starch factories produce residues that can be commercialized as food ingredients. The objective of this study was to evaluate the microbiological safety of cassava peel and bagasse during storage, with and without chemical treatment. The bagasse was acidified with lactic acid, and the peel was immersed in a sodium hypochlorite solution. The microbiological analyses were carried out for 72 h after harvest. All of the samples showed the absence of pathogenic microorganisms, and the acidification and sanitization were effective in controlling total coliforms. Cassava bagasse and peel samples can be considered safe for consumption by humans as ingredients for other food products.

  16. An Analysis of Partial DNA Sequence of Meisa1 Gene on Sweet and Bitter Cassavas (Manihot esculenta Crantz.

    Directory of Open Access Journals (Sweden)

    Dewi Indriyani Roslim

    2016-04-01

    Full Text Available Sweet and bitter taste on cassava tuber is affected by starch metabolisms. Meisa1 gene is a gene in cassava (Manihot esculenta Crantz. encoding isoamylase1 enzyme involved in starch metabolisms. This study aimed to analyze partial DNA sequences of Meisa1 gene on sweet and bitter cassavas collected by Genetics Laboratory, Department Biology, Faculty of Mathematics and Natural Sciences, Riau University, Indonesia. Methods included total DNA extraction from fresh young leaves of cassava using CTAB buffer, polymerase chain reaction (PCR, electrophoresis, and sequencing. The obtained data were analyzed using MEGA software version 5. The results showed that there were nucleotide variations in the intron region, not in the exon region. The variations were caused by the transition substitution mutation (35.39% and transversion substitution mutation (64.61%. The genetic distance range between seven cassava genotypes was approximately 0% to 11%. Partial DNA sequence variations of Meisa1 gene located in intron region were unable to cluster seven cassava genotypes separately into two groups based on tuber taste.How to CiteRoslim, D., Nisa, F., & Herman, H. (2016. An Analysis of Partial DNA Sequence of Meisa1 Gene on Sweet and Bitter Cassavas (Manihot esculenta Crantz.. Biosaintifika: Journal of Biology & Biology Education, 8(1 103-110.

  17. Starch synovitis.

    OpenAIRE

    Freemont, A. J.; Porter, M L; Tomlinson, I; Clague, R B; Jayson, M. I.

    1984-01-01

    Three patients with unexplained synovial inflammation were found to have an ulcerative, granulomatous synovitis on biopsy. Maize starch was identified in giant cells within the granulomata. Starch synovitis has clinical and histological similarities to starch peritonitis, which is thought to be an example of a cell mediated immune response.

  18. Cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Bull, Simon E

    2015-01-01

    Genetic transformation of plants is an indispensable technique used for fundamental research and crop improvement. Recent advances in cassava (Manihot esculenta Crantz) transformation have facilitated the effective generation of stably transformed cassava plants with favorable traits. Agrobacterium-mediated transformation of friable, embryogenic callus has evolved to become the most widely used approach and has been adopted by research laboratories in Africa. This procedure utilizes axillary meristem tissue (buds) to produce primary and secondary somatic embryos and subsequently friable, embryogenic callus. Agrobacterium harboring a binary expression cassette is used to transform this tissue, which is regenerated via cotyledons and shoot organogenesis to produce rooted in vitro plantlets. This chapter details each step of the procedure using the model cultivar 60444 and provides supplementary notes to successfully produce transgenic cassava.

  19. An ordered EST catalogue and gene expression profiles of cassava (Manihot esculenta) at key growth stages.

    Science.gov (United States)

    Li, You-Zhi; Pan, Ying-Hua; Sun, Chang-Bin; Dong, Hai-Tao; Luo, Xing-Lu; Wang, Zhi-Qiang; Tang, Ji-Liang; Chen, Baoshan

    2010-12-01

    A cDNA library was constructed from the root tissues of cassava variety Huanan 124 at the root bulking stage. A total of 9,600 cDNA clones from the library were sequenced with single-pass from the 5'-terminus to establish a catalogue of expressed sequence tags (ESTs). Assembly of the resulting EST sequences resulted in 2,878 putative unigenes. Blastn analysis showed that 62.6% of the unigenes matched with known cassava ESTs and the rest had no 'hits' against the cassava database in the integrative PlantGDB database. Blastx analysis showed that 1,715 (59.59%) of the unigenes matched with one or more GenBank protein entries and 1,163 (40.41%) had no 'hits'. A cDNA microarray with 2,878 unigenes was developed and used to analyze gene expression profiling of Huanan 124 at key growth stages including seedling, formation of root system, root bulking, and starch maturity. Array data analysis revealed that (1) the higher ratio of up-regulated ribosome-related genes was accompanied by a high ratio of up-regulated ubiquitin, proteasome-related and protease genes in cassava roots; (2) starch formation and degradation simultaneously occur at the early stages of root development but starch degradation is declined partially due to decrease in UDP-glucose dehydrogenase activity with root maturity; (3) starch may also be synthesized in situ in roots; (4) starch synthesis, translocation, and accumulation are also associated probably with signaling pathways that parallel Wnt, LAM, TCS and ErbB signaling pathways in animals; (5) constitutive expression of stress-responsive genes may be due to the adaptation of cassava to harsh environments during long-term evolution.

  20. Cassava For Space Diet

    Science.gov (United States)

    Katayama, Naomi; Yamashita, Masamichi; Njemanze, Philip; Nweke, Felix; Mitsuhashi, Jun; Hachiya, Natumi; Miyashita, Sachiko; Hotta, Atuko

    Space agriculture is an advanced life support enginnering concept based on biological and ecological system ot drive the materials recycle loop and create pleasant life environment on distant planetary bodies. Choice of space diet is one of primary decision required ot be made at designing space agriculture. We propose cassava, Manihot esculenta and, for one major composition of space food materials, and evaluate its value and feasibility of farming and processing it for space diet. Criteria to select space crop species could be stated as follows. 1) Fill th enutritional requirements. There is no perfect food material to meet this requirements without making a combination with others. A set of food materials which are adopted inthe space recipe shall fit to the nutritional requirement. 2) Space food is not just for maintaining physiological activities of human, but an element of human culture. We shall consider joy of dining in space life. In this context, space foos or recipe should be accepted by future astronauts. Food culture is diverse in the world, and has close relatioship to each cultural background. Cassava root tuber is a material to supply mainly energy in the form of carbohydrate, same as cereals and other tuber crops. Cassava leaf is rich in protein high as 5.1 percents about ten times higher content than its tuber. In the food culture in Africa, cassava is a major component. Cassava root tuber in most of its strain contains cyanide, it should be removed during preparation for cooking. However certain strain are less in this cyanogenic compound, and genetically modified cassava can also aboid this problem safely.

  1. Características de carcaça de novilhas mestiças confinadas, submetidas a dietas com milho ou resíduo seco de fecularia de mandioca - DOI: 10.4025/actascianimsci.v27i4.1147 Carcass traits of confined crossbred heifers subjected to corn or dry by-product of cassava starch extraction diet - DOI: 10.4025/actascianimsci.v27i4.1147

    Directory of Open Access Journals (Sweden)

    Ivanor Nunes do Prado

    2005-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a substituição do milho pelo resíduo seco de fecularia de mandioca sobre as características de carcaça (peso de carcaça quente, rendimento de carcaça, conformação, espessura do coxão, comprimento de perna, espessura de gordura de cobertura, cor, textura, área de olho de lombo, percentagem de osso, de músculo e de gordura de novilhas mestiças confinadas. Foram utilizadas 30 novilhas com 21 meses de idade. No período pré-experimental (49 dias, os animais receberam concentrado de milho e farelo de soja (19,67% PB. No período experimental (57 dias, 15 novilhas receberam a dieta anterior e outras 15 receberam resíduo de fecularia de mandioca e silagem de sorgo à vontade. A espessura da gordura de cobertura foi maior (p Longissimus dorsi (70,91 vs 63,17 cm2 e a percentagem de músculo (69,83% vs 66,29%, foram maiores (p The aim of this work was the replacement evaluation of corn by dry by-product of cassava starch extraction on carcass traits of crossbreed heifers in feedlot. Thirty crossbred heifers aged 21 months were used. In pre-experimental period (49 days the heifers were fed with soybean meal and corn concentrate (19.67% CP. In the experimental period (57 days 15 heifers were fed with the previous diet and the other 15 were fed with by-product of cassava and sorghum silage. Subcutaneous fat was thicker (P Longissimus dorsi area (70.91 vs 63.17 cm2 and the muscle percentage (69.83 vs 66.29% were highen (p < 0.05 for the heifers that consumed the diet with dry cassava by-products than the others with corn diet. The replacement of corn by dry cassava by-products influenced carcass traits

  2. Emissão de folhas e início de acumulação de amido em raízes de uma variedade de mandioca em função da época de plantio Leaf emergence and beginning of starch accumulation in roots of a cassava variety as a function of planting date

    Directory of Open Access Journals (Sweden)

    Alfredo Schons

    2007-12-01

    Full Text Available O número de folhas acumulado (NF na haste principal está associado com o aparecimento de vários estádios de desenvolvimento da cultura da mandioca. O início de acumulação de amido (IAA nas raízes tuberosas da mandioca marca o início da translocação dos fotoassimilados para o principal órgão de reserva nessa espécie. O objetivo deste trabalho foi estimar o filocrono e identificar um indicador morfológico baseado no NF para o IAA em mandioca plantada em diferentes épocas. Um experimento a campo foi conduzido em Santa Maria, RS, Brasil, com quatro épocas de plantio (28/09; 11/10; 16/11 e 27/12/2005. A variedade de mandioca usada foi a "RS 13", plantada em baldes de 12 litros, enterrados no espaçamento com 2,0 x 0,8m. O delineamento experimental foi o inteiramente casualizado com 11 repetições. A soma térmica diária (STd, °C dia foi calculada a partir da emergência e acumulada por: STa = sigmaSTd. O IAA foi determinado nas plantas de cada balde quando uma raiz atingia um diâmetro de 1cm. O NF na data do IAA e o número final de folhas (NFF até o primeiro simpódio também foram determinados. O filocrono variou de 20,3 a 29,5°C dia folha-1 e seus valores foram maiores quanto mais tardio foi o plantio. O NFF variou entre as épocas de plantio, aumentando com o atraso do plantio. O NF no IAA foi similar nas quatro épocas de plantio e ocorreu quando, em média, o NF corresponde a 20,9 (±1,0 folhas.The accumulated number of leaves (NF on the main stem is related to the appearance of several developmental stages in cassava. The beginning of starch accumulation (IAA in the fibrous roots of cassava switches the source/sink ratio because of the translocation of photoassimilates to the major storage organ in this species. This study was aimed at estimating the phyllochron and identifing a morphological indicator based on NF for IAA in cassava grown in several planting dates. A field experiment was carried out in Santa Maria, RS

  3. Digestibilidade de dietas contendo resíduo úmido de mandioca em substituição ao milho para tourinhos em terminação Replacing corn grain with a wet byproduct from cassava starch extraction on apparent digestibility of nutrients in beef cattle

    Directory of Open Access Journals (Sweden)

    José Jorge dos Santos Abrahão

    2006-08-01

    Full Text Available Avaliou-se a influência da substituição do milho pelo resíduo úmido de mandioca nos coeficientes de digestibilidade dos nutrientes e na porcentagem de NDT e EM (em Mcal/kg de dietas para tourinhos em terminação. Foram utilizados 20 animais cruzados (½ e ¾ Europeu x Zebu com 24 meses de idade e peso médio de 532 kg, provenientes de um ensaio de desempenho com as mesmas dietas deste ensaio, distribuídos em delineamento completamente casualizado, com cinco tratamentos e quatro repetições. Os tratamentos constaram de cinco dietas contendo silagem de sorgo como volumoso e 0, 25, 50, 75 e 100% de resíduo de mandioca em substituição ao milho do concentrado. As dietas não diferiram significativamente quanto aos coeficientes de digestibilidade (MS = 65,42%, PB = 68,30%; EE = 67,72%, FDN = 49,58%, FDA = 50,71%, CNF = 81,79% e aos teores de NDT = 65,47% e EM = 2,36 Mcal/kg. Somente o coeficiente de digestibilidade aparente dos CHO diferiu entre as dietas (Y= -0,0684N + 0,0015N² + 63,756; R² = 0,9122. A utilização do resíduo de mandioca em substituição ao milho, à exceção dos CHO, não alterou os coeficientes de digestibilidade dos nutrientes estudados.Twenty crossbred bulls (1/2 and 3/4 Bos taurus x Bos indicus averaging 24 months of age and 532 kg of body weight at the beginning of the experiment were used. Animals were randomly assigned to five treatments (four replicates/treatment in a completely randomized design to evaluate the effect of replacing corn grain with a wet byproduct of cassava starch extraction on apparent digestibility of nutrients. Bulls were fed diets containing sorghum silage and one of the following levels of cassava byproduct in the concentrate: 0, 25, 50, 75 or 100%. No significant differences were observed for apparent digestibility of nutrients that averaged: 65.42% (dry matter, 68.30% (crude protein, 67.72% (ether extract, 49.58% (neutral detergent fiber, 50.71% (acid detergent fiber, and 81

  4. Optimization of thermostable α- amylase production by Streptomyces erumpens MTCC 7317 in solid-state fermentation using cassava fibrous residue

    Directory of Open Access Journals (Sweden)

    Kar Shaktimay

    2010-04-01

    Full Text Available Production of α- amylase under solid state fermentation by Streptomyces erumpens MTCC 7317 was investigated using cassava fibrous residue, one of the major solid waste released during extraction of starch from cassava (Manihot esculenta Crantz. Response surface methodology (RSM was used to evaluate the effect of the main variables, i.e., incubation period (60 h, moisture holding capacity (60% and temperature (50(0C on enzyme production by applying a full factorial Central Composite Design. Varying the inoculum concentration (5-25% of S. erumpens showed that 15% inoculum (v/w, 2.5 x 10(6 CFU/ml was the optimum for α- amylase production. Among the different nitrogen sources supplemented, beef extract was most suitable for enzyme production. The application of S. erumpens enzyme in liquefaction of soluble starch and cassava starch was studied. The maximum hydrolysis of soluble starch (85% and cassava starch (70% was obtained with the application of 5 ml crude enzyme (17185 units after 5 h of incubation.

  5. Domestication Syndrome Is Investigated by Proteomic Analysis between Cultivated Cassava (Manihot esculenta Crantz and Its Wild Relatives.

    Directory of Open Access Journals (Sweden)

    Feifei An

    Full Text Available Cassava (Manihot esculenta Crantz wild relatives remain a largely untapped potential for genetic improvement. However, the domestication syndrome phenomena from wild species to cultivated cassava remain poorly understood. The analysis of leaf anatomy and photosynthetic activity showed significantly different between cassava cultivars SC205, SC8 and wild relative M. esculenta ssp. Flabellifolia (W14. The dry matter, starch and amylose contents in the storage roots of cassava cultivars were significantly more than that in wild species. In order to further reveal the differences in photosynthesis and starch accumulation of cultivars and wild species, the globally differential proteins between cassava SC205, SC8 and W14 were analyzed using 2-DE in combination with MALDI-TOF tandem mass spectrometry. A total of 175 and 304 proteins in leaves and storage roots were identified, respectively. Of these, 122 and 127 common proteins in leaves and storage roots were detected in SC205, SC8 and W14, respectively. There were 11, 2 and 2 unique proteins in leaves, as well as 58, 9 and 12 unique proteins in storage roots for W14, SC205 and SC8, respectively, indicating proteomic changes in leaves and storage roots between cultivated cassava and its wild relatives. These proteins and their differential regulation across plants of contrasting leaf morphology, leaf anatomy pattern and photosynthetic related parameters and starch content could contribute to the footprinting of cassava domestication syndrome. We conclude that these global protein data would be of great value to detect the key gene groups related to cassava selection in the domestication syndrome phenomena.

  6. Domestication Syndrome Is Investigated by Proteomic Analysis between Cultivated Cassava (Manihot esculenta Crantz) and Its Wild Relatives.

    Science.gov (United States)

    An, Feifei; Chen, Ting; Stéphanie, Djabou Mouafi Astride; Li, Kaimian; Li, Qing X; Carvalho, Luiz J C B; Tomlins, Keith; Li, Jun; Gu, Bi; Chen, Songbi

    2016-01-01

    Cassava (Manihot esculenta Crantz) wild relatives remain a largely untapped potential for genetic improvement. However, the domestication syndrome phenomena from wild species to cultivated cassava remain poorly understood. The analysis of leaf anatomy and photosynthetic activity showed significantly different between cassava cultivars SC205, SC8 and wild relative M. esculenta ssp. Flabellifolia (W14). The dry matter, starch and amylose contents in the storage roots of cassava cultivars were significantly more than that in wild species. In order to further reveal the differences in photosynthesis and starch accumulation of cultivars and wild species, the globally differential proteins between cassava SC205, SC8 and W14 were analyzed using 2-DE in combination with MALDI-TOF tandem mass spectrometry. A total of 175 and 304 proteins in leaves and storage roots were identified, respectively. Of these, 122 and 127 common proteins in leaves and storage roots were detected in SC205, SC8 and W14, respectively. There were 11, 2 and 2 unique proteins in leaves, as well as 58, 9 and 12 unique proteins in storage roots for W14, SC205 and SC8, respectively, indicating proteomic changes in leaves and storage roots between cultivated cassava and its wild relatives. These proteins and their differential regulation across plants of contrasting leaf morphology, leaf anatomy pattern and photosynthetic related parameters and starch content could contribute to the footprinting of cassava domestication syndrome. We conclude that these global protein data would be of great value to detect the key gene groups related to cassava selection in the domestication syndrome phenomena.

  7. Transcriptome response of cassava leaves under natural shade.

    Science.gov (United States)

    Ding, Zehong; Zhang, Yang; Xiao, Yi; Liu, Fangfang; Wang, Minghui; Zhu, Xinguang; Liu, Peng; Sun, Qi; Wang, Wenquan; Peng, Ming; Brutnell, Tom; Li, Pinghua

    2016-01-01

    Cassava is an important staple crop in tropical and sub-tropical areas. As a common farming practice, cassava is usually cultivated intercropping with other crops and subjected to various degrees of shading, which causes reduced productivity. Herein, a comparative transcriptomic analysis was performed on a series of developmental cassava leaves under both full sunlight and natural shade conditions. Gene expression profiles of these two conditions exhibited similar developmental transitions, e.g. genes related to cell wall and basic cellular metabolism were highly expressed in immature leaves, genes involved in lipid metabolism and tetrapyrrole synthesis were highly expressed during the transition stages, and genes related to photosynthesis and carbohydrates metabolism were highly expressed in mature leaves. Compared with the control, shade significantly induced the expression of genes involved in light reaction of photosynthesis, light signaling and DNA synthesis/chromatin structure; however, the genes related to anthocyanins biosynthesis, heat shock, calvin cycle, glycolysis, TCA cycle, mitochondrial electron transport, and starch and sucrose metabolisms were dramatically depressed. Moreover, the shade also influenced the expression of hormone-related genes and transcriptional factors. The findings would improve our understanding of molecular mechanisms of shade response, and shed light on pathways associated with shade-avoidance syndrome for cassava improvement. PMID:27539510

  8. Transcriptome response of cassava leaves under natural shade.

    Science.gov (United States)

    Ding, Zehong; Zhang, Yang; Xiao, Yi; Liu, Fangfang; Wang, Minghui; Zhu, Xinguang; Liu, Peng; Sun, Qi; Wang, Wenquan; Peng, Ming; Brutnell, Tom; Li, Pinghua

    2016-01-01

    Cassava is an important staple crop in tropical and sub-tropical areas. As a common farming practice, cassava is usually cultivated intercropping with other crops and subjected to various degrees of shading, which causes reduced productivity. Herein, a comparative transcriptomic analysis was performed on a series of developmental cassava leaves under both full sunlight and natural shade conditions. Gene expression profiles of these two conditions exhibited similar developmental transitions, e.g. genes related to cell wall and basic cellular metabolism were highly expressed in immature leaves, genes involved in lipid metabolism and tetrapyrrole synthesis were highly expressed during the transition stages, and genes related to photosynthesis and carbohydrates metabolism were highly expressed in mature leaves. Compared with the control, shade significantly induced the expression of genes involved in light reaction of photosynthesis, light signaling and DNA synthesis/chromatin structure; however, the genes related to anthocyanins biosynthesis, heat shock, calvin cycle, glycolysis, TCA cycle, mitochondrial electron transport, and starch and sucrose metabolisms were dramatically depressed. Moreover, the shade also influenced the expression of hormone-related genes and transcriptional factors. The findings would improve our understanding of molecular mechanisms of shade response, and shed light on pathways associated with shade-avoidance syndrome for cassava improvement.

  9. Substituição do milho pelo resíduo de fecularia de mandioca sobre o desempenho, digestibilidade e características de carcaça de novilhos confinados = Replacing corn with cassava starch by-products on the performance, digestibility and carcass characteristics of bulls in confinement

    Directory of Open Access Journals (Sweden)

    Maribel Velandia Valero

    2009-10-01

    Full Text Available O efeito de substituição do milho pelo resíduo desidratado de fecularia de mandioca (0; 12,5; 22,8 e 32,7% foi avaliado sobre o desempenho, a digestibilidade e características de carcaça e 32 bovinos mestiços (½ Nelore x ½ Angus de aproximadamente 18 meses de idade e 380 kg de peso vivo. O delineamento experimental foi o inteiramente casualizado, com quatro tratamentos e oito repetições. Foram analisados o ganho médio diário (GMD, rendimento de carcaça (RC, espessura de gordura de cobertura (EGC, área de olho de lombo (AOL, comprimento de perna (CP, espessura de coxão (EC, ingestãode matéria seca (IMS, conversão alimentar (CA, digestibilidade total aparente da matéria seca (DAMS, matéria orgânica (DAMO, proteína bruta (DAPB, energia bruta (DAEB, fibra em detergente ácido (DAFDA e fibra em detergente neutro (DAFDN. O experimento foidesenvolvido durante um período de 56 dias, após 14 dias de adaptação. Os resultados de GMD, RC, CA, EGC, AOL, CP e EC não apresentaram diferenças (p > 0,05 entre os tratamentos. A IMS apresentou redução linear quando o milho foi substituído pelo resíduodesidratado de fecularia de mandioca. Os coeficientes de digestibilidade da MS, MO, PB, EB, FDN e FDA não variaram entre as rações experimentais.The effects of replacing corn with different levels of cassava starch by-products (0; 12.5; 22.8; and 32.7% were evaluated on performance, digestibility and carcass traits of feedlot bulls. Thirty-twocrossbred bulls (½ Nelore x ½ Angus around 18 months of age and 380 kg of body weight were used. A completely randomized design was used, with 4 treatments and 8 replicates. Evaluated traits were: average daily gain (ADG, carcass dressing (CD, backfat thickness (BT, Longissimus area (LDA, leg length (LL and cushion thickness (CT, dry matter intake (DMI, feed conversion ratio (FCR, total apparent digestibility of dry matter (DMDC, organic matter (OMDC, crude protein (CPDC, crude energy (CEDC

  10. [Degradation of cassava residue by the cellulose degradation composite microbial system MC1].

    Science.gov (United States)

    Guo, Peng; Wang, Xiao-Fen; Zhu, Wan-Bin; Cheng, Xu; Cui, Zong-Jun

    2008-03-01

    The lignocelluloses of cassava residue are good biomass resources. They are mainly used to produce feeds and alcohol. It is a promising approach to utilize them to produce methane. But it is difficult to use cassava residue for producing methane because of its dispersive solid matter and much water. A cellulose degradation composite microbial system MC1 was applied to degrade cassava residue discarded from cassava starch manufactory, and the composition of the lignocelluloses and the soluble ingredients of cassava residue were analyzed. After 18 days' cultivation, the total weight of the cassava residue was reduced by 47.3%, the cellulose, hemi-cellulose and lignin of the cassava residue were reduced by 22.7%, 90.4% and 11.3%, respectively, and 85% of the whole weight relief was made by MC1 within 6 days. The soluble ingredients of the cassava residue were increased from the incipient 18% to 33% in the third day which was the peak value in the process. The total amount of the volatile products, analyzed by GC-MS, came to a maximum in the sixth day. Twelve kinds of volatile products in the fermentation broth were determined, in which ethanol, acetic acid, 1, 2-ethanediol, butanoic acid and glycerine were the major compounds, and they can be utilized by methanogenic organism directly or be changed into compounds that can be utilized by methanogens organism directly. Accordingly, it is very hopeful to use MC1 to degrade cassava residue as a method of prefermentation in methane fermentation.

  11. Continuous 2-keto-D-gluconic acid production from rice starch hydrolysate by Pseudomonas fluorescens JD1202%荧光假单胞菌JD1202利用大米淀粉水解糖连续发酵生产2-酮基-D-葡萄糖酸

    Institute of Scientific and Technical Information of China (English)

    余泗莲; 汪美生; 孙文敬; 崔凤杰; 魏转; 余彬; 周强; 齐向辉; 王亮

    2012-01-01

    A continuous fermentation process of 2 -keto -D -gluconic acid (2KGA) production from rice starch hy-drolysate was developed using Pseudomonas fluorescens JD1202. The effects of starting point of continuous fermenta tion, dilution rate and feeding glucose concentration on 2KGA production were investigated. Results showed that the dilution rate and feeding glucose concentration had a significant effect on 2KGA production performance. When the dilution and media composition were at a stable level, the fermentation can start at any point, there had no significance of the concentrations of cell, substrate and product. The optimal operating factors were obtained as: 0.065 h -1 of dilution rate and 170. 0 g/L of feeding glucose concentration. Under these conditions, the steady state produced 2KGA at the concentration of 130. 34 g/L, average volumetric productivity of 8. 47 g/L h and the fermentation conversion rate of 89. 46%. In conclusion, this efficient continuous fermentation process by the strain Pseudomonas fluorescens JD1202 is competitive for industrial production 2KGA from rice starch hydrolysate.%研发荧光假单胞菌JD1202转化大米淀粉水解糖为2-酮基-D-葡萄糖酸的连续发酵工艺.考察了连续发酵起点、稀释率和补料培养基中葡萄糖浓度对2-酮基-D-葡萄糖酸生产的影响.结果表明,稀释率和葡萄糖浓度对2-酮基-D-葡萄糖酸发酵具有显著影响;在稀释率和补料培养基成分保持不变的条件下,2-酮基-D-葡萄糖酸大量合成期的任何时段均可作为连续发酵的起点,其细胞浓度、残糖浓度和2-酮基-D-葡萄糖酸浓度均稳定在一定范围.较适的连续发酵操作条件为:稀释率0.065h-1,补料培养基中葡萄糖的质量浓度为170.0g/L.在此条件下,连续发酵达到稳态时发酵液中2-酮基-D-葡萄糖酸的质量浓度为130.34g/L,生产强度平均为8.47g/L·h,发酵转化率为89.46%.连续发酵工艺是一种高效的2-酮基-D-葡萄糖

  12. Hidratação de tecidos de raízes de mandioca (Manihot esculenta Crantz. e gelatinização do amido durante a cocção Hydration of cassava tissues and starch gelatinization during the cooking process

    Directory of Open Access Journals (Sweden)

    Soraya S. Butarelo

    2004-09-01

    Full Text Available Durante a cocção da mandioca ocorrem modificações físicas e químicas nos tecidos e a textura final é importante para a aceitabilidade e o consumo de mandiocas. A cocção a 80° e em água em ebulição de duas cultivares, aos 12 e 25 meses após o plantio, foi acompanhada determinando-se o ganho de peso (hidratação e o grau de gelatinização das amostras. Gelatinização foi determinada por colorimetria com iodo após dissolução em álcali das amostras cozidas por diferentes períodos de tempo. A 80°C a hidratação e a gelatinização não se completaram, o que ocorreu com a cocção em água em ebulição. O grau de hidratação foi diferente entre cultivares e entre amostras de 12 e 25 meses de plantio e pode ser descrito matematicamente por modelo de ordem zero. Amostras colhidas 12 meses após ao plantio hidrataram mais rápido que aos 25 meses e a cultivar IAPAR-19 Pioneira hidratou mais rápido que a cultivar Catarina Amarela. Quanto mais rápida a hidratação mais rápido o cozimento e quanto maior a hidratação maior o rendimento em produto cozido.Cooking of cassava root tissues causes both physical and chemical modifications and the final texture of the product is important for the acceptability and consumption of the food. Cooking tissue samples at 80° and in boiling water from two cultivars, harvested 12 and 25 months after planting date, was accompanied by determinig weight gain and starch gelatinization of the samples. Starch gelatinization was determined by colorimetry with iodine after solubilization in alkali of samples cooked for different period of times. At 80°C neither hydration or gelatinization were complete, which occurred at in boiling water. Hydration was different between cultivars and harvesting ages and could be described by a zero order mathematical model. Samples harvested 12 months after planting date hydrated faster than the ones harvested after 25 months and IAPAR-19 Pioneira hydrated faster

  13. Efeito da concentração de fibra e parâmetros operacionais de extrusão sobre as propriedades de pasta de misturas de fécula de mandioca e polpa cítrica Effect of the fiber content and operational extrusion parameters on the pasting characteristics of cassava starch and orange pulp mixture

    Directory of Open Access Journals (Sweden)

    Luciana Bronzi de Souza

    2010-09-01

    Full Text Available Para preencher as várias demandas para funcionalidades em produtos alimentícios, a fécula de mandioca misturada à polpa de laranja desidratada foi extrusada sob diferentes condições (0 a 20% de fibras na mistura; (14,6 a 21,4% de umidade e (60,8 a 129 ºC de temperatura de extrusão, objetivando o uso em produtos instantâneos ricos em fibras. A rotação da rosca foi mantida constante em 272 rpm, a abertura da matriz foi 3 mm, a taxa de compressão da rosca foi 3:1 e a taxa de alimentação foi de 150 g/minuto. Os produtos extrusados moídos foram analisados para as propriedades de pasta: viscosidade inicial, pico de viscosidade, quebra de viscosidade, viscosidade final e tendência à retrogradação no Rapid Visco Analyser (RVA, tendo em vista a importância destes parâmetros para este tipo de utilização. Os resultados obtidos mostraram que a porcentagem de fibras foi o parâmetro de maior influência nas propriedades de pasta, e que nas condições de baixo teor de fibras, elevada temperatura e baixa umidade pode ter ocorrido degradação acentuada do amido e solubilização das fibras, levando à redução dos parâmetros de viscosidade.Due the various demands for processed foods with functional ingredients, a mixture of cassava starch and dried orange pulp was extruded under different conditions (0 to 20% of fibers in the mixture; (14.6 to 21.4% moisture; and (60.8 to 129 ºC temperature of extrusion aiming at the use in high fiber instant products. The screw speed was kept constant (272 rpm, the diameter of die was 3 mm, the compression ratio was 3:1, and the feed rate was 150 g/minute. The following pasting properties of the extruded products were analyzed: initial viscosity, peak of viscosity, breakdown, final viscosity, and retrogradation tendency using a Rapid Visco Analyser (RVA in view of the importance of these parameters for such use. The results showed that the percentage of fibers was the greatest variable of influence

  14. CORROSION INHIBITION OF CASSAVA STARCH GRAFT ACRYL AMIDE COPOLYMER FOR COLD ROLLED STEEL IN HYDROCHLORIC ACID%木薯淀粉接枝共聚物在盐酸介质中对冷轧钢的缓蚀作用

    Institute of Scientific and Technical Information of China (English)

    付惠; 李向红; 李云仙; 刘建祥

    2011-01-01

    采用氧化还原引发体系引发木薯淀粉与丙烯酰胺接枝共聚反应制备的天然木薯淀粉接枝共聚物(SGA),可以作为一种环境友好型“绿色”缓蚀剂。本文用失重法、动电位极化曲线、电化学阻抗(EIS)和扫描电子显微镜(SEM)首次研究了SGA在1.0mol/LHCl溶液中对冷轧钢的缓蚀作用。结果表明,SGA对冷轧钢具有良好的缓蚀作用,在钢表面的吸附符合Langmuir吸附等温式,为混合抑制型缓蚀剂;EIS谱呈半圆容抗弧,电荷转移电阻随缓蚀剂浓度的增加而增大。SEM表明SGA在钢表面吸附形成了致密的缓蚀剂膜层。%Cassava starch graft acryl amide copolymer (SGA) was prepared by grafting acryl amide onto starch with oxidization reduction reaction, which can be used as a good environmentally-friendly "green" inhibitor. The inhibition effect of SGA on the corrosion of cold rolled steel (CRS) in 1.0 mol/L HCl has been studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) methods. The results show that SGA is a good inhibitor in 1.0 mol/L HC1 for CRS, and the adsorption of SGA on the CRS surface obeys Langmuir adsorption isotherm. Polarization curves show that SGA is a mixed-type inhibitor in hydrochloric acid. All EIS spectra exhibit one capacitive loop, and the charge transfer resistance increases with the inhibitor concentration. SEM results show that the introduction of SGA into HCl solution results in the formation of a compact and dense inhibitive film on the CRS surface.

  15. Influence of Mucilage Viscosity On The Globule Structure And Stability Of Certain Starch Emulsions

    Directory of Open Access Journals (Sweden)

    Uhumwangho MU

    2005-05-01

    Full Text Available A study was carried out to determine the influence of mucilage viscosity on the globule structure (i.e. size and number of certain starch emulsions. The starches investigated were cassava, potato and maize. The emulsions were prepared by mixing the starch mucilage of a predetermined concentration 4%w/v with arachis oil in the ratio 50:50, using a silverson mixer fitted with a dispersator head. The emulsions were stored at room temperature (28±20C for 7 days. Changes in globule size were monitored by photomicroscopy. Viscosities of the mucilage and those of resulting emulsions were determined using a capillary flow method. The viscosities of the emulsions expressed as time of flow (seconds, were 680 (cassava starch, 369 (potato starch and 270 (Maize starch, and for the mucilage 510 (cassava, 336 (potato and 248 (maize. The corresponding mean globule sizes of the fresh emulsions were (µm 28±6, 42±6 and 45±5 respectively. The increase in globule size during storage (measure of globule coalescence rate was 1.8±0.2µm day -1 (cassava, 3.5±0.2µm day -1 (potato and 4.6±0.3µm day -1 (maize. Thus, a higher viscosity of the dispersion medium is associated with the production of finer and more stable emulsions.

  16. Utilization of cassava waste through fermentation technology

    International Nuclear Information System (INIS)

    Over 400 isolates of molds were screened for raw starch digesting enzymes and aspergillus J8 ad Rhizopus N37 were selected for further investigations. Crude enzymes obtained from wheat bran was higher than from rice bran. Crude enzymes from Aspergillus is active at pH 4.0, whereas that from Rhizopus is active at pH 5.0. Aspergillus J8 gave higher yield of silage fermentation. Selection of yeast strain was accomplished, it was found that Saccharomyces cerevisiae SC90, the local commercial strain (non-flocculent) performed best in fermentation of cassava mash. Another strain AM12, a flocculent fusant strain derived from fusion between flocculent strain and sake brewing strain was comparable to that of commercial strain at normal temperature but performed better at higher temperature up to 40 deg C. It is unlikely that fuel alcohol produced from raw cassava will be able to compete with petroleum fuel at this moment. However, silage fermentation to increase nutritional quality of the silage through selected strains of microorganisms has a good prospect to pursue. (author)

  17. Characterization of starch and other components from African crops and quality evaluation of derived products

    International Nuclear Information System (INIS)

    Research was carried out on African staple foods on characterization of components of cereals and tubers, and quality evaluation of foods manufactured from composite flours. Cereal starch, alimentary fiber and minerals from cassava were investigated. Starch was isolated under conditions of minimum damage from seeds of three sorghum and two fonio cultivars, and its physico-chemical properties were compared with commercial wheat starch. Fiber, ash and mineral content of samples of genetically improved varieties of cassava from Ghana were determined to understand the role of factors that influence texture of cooked products. Bread and pasta were produced from either triticale alone or in combination with different amounts of cassava flour, and by varying the amount of wheat flour. The organoleptic quality of the raw materials and final products were determined. (author). 15 refs, 10 tabs

  18. Recent growth in African cassava

    OpenAIRE

    Nweke, Felix; Haggblade, Steven; Zulu, Ballard

    2004-01-01

    According to the authors, "Cassava serves as a staple food for 200 million Africans, second only to maize in its calorie contribution. In response to a series of devastating attacks by cassava diseases and pests over the past several decades, the International Institute of Tropical Agriculture (IITA) and several national agricultural research services have launched successful cassava research programs... " This brief describes some of the programs, their impact and the drivers of change. It c...

  19. Feeding cassava foliage to sheep

    OpenAIRE

    Hue, Khuc Thi

    2012-01-01

    The potential of cassava foliage (Manihot esculenta Crantz) as a protein-rich feed in sheep production in Vietnam was examined by studying cassava foliage yield, hydrogen cyanide (HCN) content, toxicity and performance of lambs fed the foliage as a supplement. Cassava foliage fed ad libitum as a protein supplement to a basal diet of urea-treated rice straw gave similar lamb live weight gain (LWG) as diets supplemented with commercial concentrate or protein-rich foliage of stylosanthes (S...

  20. Synthesis and Characterization of Starch-Poly (Butyl Methacrylate) Graft Copolymers

    International Nuclear Information System (INIS)

    The graft copolymerization was carried out by buthyl methacrylate with starch in which azobisisobutyronitrile was used as an initiator. The grafting reactions were carried out within out a 70-90 oC temperature range, and the effect of the monomer, initiator concentrations, and the amount of starch on the graft yield were also investigated. The maximum graft yield was obtained at a azobisisobutyronitrile concentration of 1 : 0.3 - 1 : 1.5 mol/L. The grafted starches were characterized with infrared spectroscopy, scanning electron microscopy, and thermogravimetry. The cassava starch-g-BMA copolymer was synthesized by batch and continuous method. The graft copolymer confirmed initially by FT-IR spectra. The absorption band of C=O stretching appeared at 1730 cm-1. This band was characteristic band of the carbonyl group existing in PBMA. Therefore, this indicated that PBMA was grafted onto the cassava starch backbone. The formation of cassava starch -g-PBMA was also supported by SEM analysis. The grafting characteristics of the obtained cassava starch-g-PBMA were affected by several parameters, including the ratio of starch and BMA reactants, the reaction temperature and the reaction time. When the grafting characteristics were considered, especially the grafting yield in association with the amounts of reactants and initiator and also the time consumed in the process, the results suggested that the optimum performance were ratio starch/BMA 1 : 0.3, AIBN 0.5 % w/w at 90 oC proper for this graft copolymerization system with graft yield 36.7 % and optimum graft yield 75.6 % result from ratio starch/BMA 1 : 1.5, AIBN 0.5 % w/w at 80 oC. (author)

  1. Two cassava promoters related to vascular expression and storage root formation.

    Science.gov (United States)

    Zhang, Peng; Bohl-Zenger, Susanne; Puonti-Kaerlas, Johanna; Potrykus, Ingo; Gruissem, Wilhelm

    2003-12-01

    Cassava ( Manihot esculenta Crantz) storage roots, organs accumulating large amounts of starch, develop from primary roots via secondary growth. The availability of promoters related to storage-root formation is a prerequisite for engineering root traits in cassava. Two cDNAs, c15 and c54, were identified from a storage-root cDNA library of cassava MCol1505 via differential screening. The transcripts of c15 and c54 were detected in storage roots but not in leaves by Northern analysis. Homology analysis of the deduced amino acid sequences showed that C15 is likely to be related to cytochrome P450 proteins, which are involved in the oxidative degradation of various compounds, while C54 may be related to Pt2L4, a cassava glutamic acid-rich protein. The promoter regions of c15 and c54 were isolated from the corresponding clones in a cassava genomic library. A 1,465-bp promoter fragment ( p15/1.5) of c15 and a 1,081-bp promoter region ( p54/1.0) of c54 were translationally fused to the uidA reporter gene, and introduced into cassava and Arabidopsis thaliana (L.) Heynh. The expression patterns of p15/1.5::uidA and p54/1.0::uidA in transgenic plants showed that both promoters are predominantly active in phloem, cambium and xylem vessels of vascular tissues from leaves, stems, and root systems. More importantly, strong beta-glucuronidase activity was also detected in the starch-rich parenchyma cells of transgenic storage roots. Our results demonstrate that the two promoters are related to vascular expression and secondary growth of storage roots in cassava.

  2. Protein hydrolysates in sports nutrition

    Directory of Open Access Journals (Sweden)

    Manninen Anssi H

    2009-09-01

    Full Text Available Abstract It has been suggested that protein hydrolysates providing mainly di- and tripeptides are superior to intact (whole proteins and free amino acids in terms of skeletal muscle protein anabolism. This review provides a critical examination of protein hydrolysate studies conducted in healthy humans with special reference to sports nutrition. The effects of protein hydrolysate ingestion on blood amino acid levels, muscle protein anabolism, body composition, exercise performance and muscle glycogen resynthesis are discussed.

  3. Pullulanase: Role in Starch Hydrolysis and Potential Industrial Applications

    OpenAIRE

    Siew Ling Hii; Joo Shun Tan; Tau Chuan Ling; Arbakariya Bin Ariff

    2012-01-01

    The use of pullulanase (EC 3.2.1.41) has recently been the subject of increased applications in starch-based industries especially those aimed for glucose production. Pullulanase, an important debranching enzyme, has been widely utilised to hydrolyse the α -1,6 glucosidic linkages in starch, amylopectin, pullulan, and related oligosaccharides, which enables a complete and efficient conversion of the branched polysaccharides into small fermentable sugars during saccharification process. The in...

  4. Acid and enzymatic hydrolysis to recover reducing sugars from cassava bagasse: an economic study

    Directory of Open Access Journals (Sweden)

    Woiciechowski Adenise Lorenci

    2002-01-01

    Full Text Available The objective of this work was to study the acid and enzymatic hydrolysis of cassava bagasse for the recovery of reducing sugars and to establish the operational costs. A statistical program "Statistica", based on the surface response was used to optimize the recovery of reducing sugars in both the processes. The process economics was determined considering the values of reducing sugars obtained at laboratory scale, and the operations costs of a cylindrical reactor of 1500 L, with flat walls at the top and bottom. The reactor was operated with 150 kg of cassava bagasse and 1350 kg of water. The yield of the acid hydrolysis was 62.4 g of reducing sugars from 100 g of cassava bagasse containing 66% starch. It represented 94.5% of reducing sugar recovery. The yield of the enzymatic hydrolysis was 77.1 g of reducing sugars from 120 g of cassava bagasse, which represented 97.3% of reducing sugars recovery. Concerning to the time, a batch of acid hydrolysis required 10 minutes, plus the time to heat and cool the reactor, and a batch of the enzymatic hydrolysis needed 25 hours and 20 minutes, plus the time to heat and to cool the reactor. Thus, the acid hydrolysis of 150 kg of cassava bagasse required US$ 34.27, and the enzymatic hydrolysis of the same amount of cassava bagasse required US$ 2470.99.

  5. Properties of extruded xanthan-starch-clay nanocomposite films

    Directory of Open Access Journals (Sweden)

    Cristina de Melo

    2011-12-01

    Full Text Available The aim of this work was to manufacture the biodegradable nanocomposite films by extrusion from different combinations of cassava starch, xanthan gum and nanoclays (sodium montmorillonite - MMT- Na and to characterize them according to their microstructure, optical, mechanical and barrier properties. Films were manufactured from nine starch/xanthan/nanoclay combinations, containing glycerol as plasticizer. Scanning electron microscopy (SEM of the starch-xanthan extruded films showed reticulated surface and smooth interior, indicating that the gum was mostly concentrated on the surface of the films, while starch/xanthan/nanoclays films showed a more homogeneous surface, suggesting that the introduction of nanoclays provided a better biopolymeric interaction. In general, nanoclays addition (2.5 - 5.0, w% generated more transparent and resistant films, with lower water vapor permeabilities and lower water sorption capacities and xanthan gum addition improved the elongation ofa starch films.

  6. Strategies for elimination of cyanogens from cassava for reducing toxicity and improving food safety.

    Science.gov (United States)

    Nambisan, Bala

    2011-03-01

    Toxicity of cassava arises due to the presence of the cyanoglucosides linamarin and lotaustralin which are hydrolysed by endogenous enzyme linamarase to acetonecyanohydrin (ACN) and cyanide (CN) which are toxic. Major research efforts to eliminate/reduce cyanoglucosides have focused on (i) development of acyanogenic cassava varieties by breeding; (ii) controlling its metabolism; and (iii) processing to remove cyanogens. The cyanoglucoside (CNG) content in cassava is genetically controlled and cultivars may be classified as low (100 μg CN eq./g) varieties. Molecular techniques for reducing tuber CNG have focused on development of transgenic plants with reduced expression of cyt P 450 in leaves, or increased expression of hydroxynitrilelyase in tuber. For immediate solution, CNG content can be reduced using several processing methods. Traditional methods used for processing include boiling, drying, parboiling and drying, baking, steaming, frying and preparation of flour. These processes result in CN losses ranging from 25% to 98%. The cyanogen level in the final product is influenced both by the tuber CNG and the method of processing. In order to achieve safe levels of 10 μg/g in cassava products, new methods of processing, especially for cassava containing more than 250 μg CN eq./g, remains a challenging problem.

  7. Comparative Proteome Analysis of the Tuberous Roots of Six Cassava (Manihot esculenta) Varieties Reveals Proteins Related to Phenotypic Traits.

    Science.gov (United States)

    Schmitz, Gabriela Justamante Händel; de Magalhães Andrade, Jonathan; Valle, Teresa Losada; Labate, Carlos Alberto; do Nascimento, João Roberto Oliveira

    2016-04-27

    Cassava (Manihot esculenta Crantz) is a staple food and an important source of starch, and the attributes of its tuberous root largely depend on the variety. The proteome of cassava has been investigated; however, to date, no study has focused on varieties that reveal the molecular basis of phenotypical characteristics. Therefore, we aimed to compare the proteome of the tuberous roots of six cassava varieties that differed in carbohydrates, carotenoids, and resistance to diseases, among other attributes. Two-dimensional gels showed 146 differential spots between the varieties, and the functional roles of some differential proteins were correlated to phenotypic characteristics of the varieties, such as the amount of carbohydrates or carotenoids and the resistance to biotic or abiotic stresses. The results obtained here highlight elements that might help to direct the improvement of new cultivars of cassava, which is an economically and socially relevant crop worldwide.

  8. Comparative Proteome Analysis of the Tuberous Roots of Six Cassava (Manihot esculenta) Varieties Reveals Proteins Related to Phenotypic Traits.

    Science.gov (United States)

    Schmitz, Gabriela Justamante Händel; de Magalhães Andrade, Jonathan; Valle, Teresa Losada; Labate, Carlos Alberto; do Nascimento, João Roberto Oliveira

    2016-04-27

    Cassava (Manihot esculenta Crantz) is a staple food and an important source of starch, and the attributes of its tuberous root largely depend on the variety. The proteome of cassava has been investigated; however, to date, no study has focused on varieties that reveal the molecular basis of phenotypical characteristics. Therefore, we aimed to compare the proteome of the tuberous roots of six cassava varieties that differed in carbohydrates, carotenoids, and resistance to diseases, among other attributes. Two-dimensional gels showed 146 differential spots between the varieties, and the functional roles of some differential proteins were correlated to phenotypic characteristics of the varieties, such as the amount of carbohydrates or carotenoids and the resistance to biotic or abiotic stresses. The results obtained here highlight elements that might help to direct the improvement of new cultivars of cassava, which is an economically and socially relevant crop worldwide. PMID:26982619

  9. Sensorial evolution of cassava flour (Manihot esculenta crantz) added to protein concentrate cassava leaves

    OpenAIRE

    Lima, Elaine C S; Feijo, Márcia B S; Freitas, Maria C J; dos Santos, Edna R; Armando U.O. SABAA-SRUR; Moura, Luciana S M

    2012-01-01

    Cassava is regarded as the nutritional base of populations in developing countries, and flour, product made of cassava, is the most consumed in the world. The cassava leaves are very rich in vegetable proteins, but a big amount is lost in processing the crop. The objective of this study was to do a sensory evaluation of cassava flour to which a protein concentrate obtained from cassava leaves (CPML) was added. The CPML was obtained from cassava leaves by isoelectric precipitation and added to...

  10. Towards the development of a chimera-free in vitro induced mutagenesis system in cassava (Manihot esculenta, Crantz)

    International Nuclear Information System (INIS)

    Cassava, an herbaceous plant with starchy storage roots, has the potentials for being the cheapest source of starch for varied industries. To achieve this, the starch types must be clearly discriminated into either high preponderance of amylose or the other extreme of amylopectin content (waxy starch). Being a vegetative propagated crop with major crossing barriers, induced mutagenesis holds promise for modifying the starch characteristics of this crop. The efficiency of induced mutagenesis in a vegetative propagated crop such as cassava is severely limited by the occurrence of chimeras. To ameliorate this, the induced mutagenesis strategy must permit the regeneration of plants from one or a few cells that have been induced to mutate. We report the optimisation of protocols for the generation of plantlets from somatic embryos that were exposed to EMS. Different explants (buds and somatic embryos) of a cassava clone with high starch content were exposed to different doses (concentration and duration) of ethylmethane sulfonate (EMS) with the aim of determining the optimal doses for generating induced mutants. A wide range of reactions to EMS, from slightly reduced plantlet regeneration to lethality, was observed leading to the determination of the optimum exposure treatment. The regenerated plantlets were transplanted to pots in the greenhouse for hardening and later transferred to the field. In order to achieve homozygousity of the mutation events, the putative mutants were selfed- crosses. The immature embryos were rescued (cultured on aseptic growth media) in order to speed-up the process of generating the mutant population as well as avoid the possibility of embryo abortion. The resulting plantlets were again subsequently hardened and transferred to the field. Currently, 610 plants, constituting the putative mutant population have been established in the field in Palmira, Colombia. As a pilot assay, this work has demonstrated the feasibility of combining EMS

  11. Cassava as an energy crop

    DEFF Research Database (Denmark)

    Kristensen, Søren Bech Pilgaard; Birch-Thomsen, Torben; Rasmussen, Kjeld;

    2014-01-01

    Cassava based bioethanol production is a promising alternative to conventional fossil fuels and commercial production is already well established in several countries. A production based on small holder production may involve a transformation of the existing production system and it is therefore...... imperative to investigate opportunities and barriers for expansion of cassava production. This paper investigates the potential for an expansion of cassava cultivation for bioethanol production in Southern Mali. It is based on a questionnaire survey with 65 households in 2 villages in Loulouni municipality......, which represent two major agro-ecological environments in the Soudan-zone in Mali. The results reveal that farmers are experienced cassava producers and are interested in an expansion of cassava cultivation for bioethanol production and that suitable areas are available, especially for an expansion...

  12. Study on sythesis of environment-friendly wood adhesive based-on cassava starch Ⅰ :The formula optimization through uniform design%木薯淀粉基环保型木材胶粘剂的合成研究(Ⅰ)——基于均匀设计的配方优化

    Institute of Scientific and Technical Information of China (English)

    甘卫星; 苏发导; 汤衍荣; 严永林; 江文; 李东飞; 赵仁杰

    2011-01-01

    The environmentally friendly wood adhesive was synthesized by raw materials of cassava starch, mela-mine, formaldehyde and crosslinking agent. To improve the bonding strength and reduce the emission of free formaldehyde, the experiments were optimized through uniform design, the bonding strength of the adhesive was detected and analyzed, and the optimal formula was chosen, which was practical and good function. The experiment results show that:(l) The best conditions for the synthesis process were mole ratio of formaldehyde to melamine 2. 2, mass ratio of crosslinking agent to water was 2. 5% ;(2) The optimum technological parameters for producing plywood were determined as follows: hot-press temperature 155℃ , hot-pressing time 370 s, filler 22%; (3) The bonding strength of the adhesive met the requirements of the Plywood II of the National Standard (GB/T14732 - 2006), the emission of free formaldehyde of the plywood satisfied E2 of GB/T18580 - 2001, part of them satisfied E1.%以木薯淀粉、三聚氰胺、甲醛为原料,再辅以交联剂合成了环保型木材胶粘剂.通过均匀设计来优化实验,并对其胶合强度进行检测和分析,从胶合强度和甲醛释放量等方面考虑,寻求性能良好且又实用的最优配方.实验结果表明:(1)胶粘剂最佳合成条件为:三聚氰胺与甲醛的摩尔比为2.2,盐酸/水质量百分比为2.5%;(2)胶合板最佳胶合工艺为:热压温度为155℃、热压时间为367 s、填料为22%、固化剂为1.4%;(3)胶合强度均达到了国家标准(GB/T14732- 2006)Ⅱ类胶合板的要求,压制胶合板的游离甲醛释放量都达到E2级,部分达到E1级.

  13. Desenvolvimento e avaliação da eficácia de filmes biodegradáveis de amido de mandioca com nanocelulose como reforço e com extrato de erva-mate como aditivo antioxidante Development and evaluation of the effectiveness of biodegradable films of cassava starch with nanocelulose as reinforcement and yerba mate extract as an additive antioxidant

    Directory of Open Access Journals (Sweden)

    Bruna Aparecida Souza Machado

    2012-11-01

    Full Text Available O objetivo do trabalho foi desenvolver uma embalagem biodegradável utilizando como matriz polimérica o amido de mandioca plastificada com glicerol e reforçada com a incorporação de nanocelulose da fibra de coco, bem como, avaliar o efeito da adição de um aditivo natural (erva-mate nas formulações de nanobiocompósitos com ação antioxidante. Os nanocristais de celulose (L/D=39 foram obtidos por hidrólise ácida com H2SO4 a 65%. Os filmes foram preparados por casting contendo 4,5 e 6,0% de amido, 0,5 e 1,5% de glicerol, 0,3% de nanocelulose e 20% de extrato de erva-mate. O armazenamento do azeite de dendê embalado com os filmes contendo o aditivo foi monitorado por 40 dias sob condições de oxidação acelerada (63%UR/30°C. Constatou-se que, à medida que aumentam as perdas de Polifenóis Totais nos filmes, ocorre um menor aumento do Índice de Peróxidos do produto embalado, demonstrando, assim, que, ao invés do produto, os compostos da embalagem é quem estão sofrendo oxidação. A incorporação de extrato de erva-mate não alterou as propriedades mecânicas e de barreira desses filmes.The objective was to develop biodegradable packaging using a polymer matrix as the cassava starch plasticized with glycerol and reinforced with the incorporation of nanocelulose of coconut fiber, as well as to evaluate the effect of the addition of an additive nature (yerba mate in nanobiocompósitos formulations with antioxidant action. The nanocrystal cellulose (L/D=39 were obtained by acid hydrolysis with 65% H2SO4. The films were prepared by casting containing 4.5 and 6.0% starch, 0.5 and 1.5% glycerol, 0.3% nanocelulose and 20% extract of yerba mate. The palm oil storage packed with films containing the additive was monitored for 40 days under conditions of accelerated oxidation (63%UR/30°C. It was found that as the losses increase polyphenol films, there is a smaller increase of the peroxide value of the packaged product, thus

  14. Characterization of different cassava samples by nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Cassava root (Manihot esculenta Crantz) is grown in all Brazilian states, being an important product in the diet of Brazilians. For many families of the North and Northeast states, it may represent the main energy source. The cassava root flour has high levels of starch, in addition to containing fiber, lipids and some minerals. There is, however, great genetic variability, which results in differentiation in its chemical composition and structural aspect. Motivated by the economic, nutritional and pharmacological importance of this product, this work is aimed at characterizing six cassava flour samples by NMR spectroscopy. The spectra revealed the main chemical groups. Furthermore, the results confirmed differences on chemical and structural aspect of the samples. For instance, the F1 sample is richer in carbohydrates, while the F4 sample has higher proportion of glycolipids, the F2 sample has higher amylose content and the F6 sample exhibits a greater diversity of glycolipid types. Regarding the molecular structure, the NMR spectra indicated that the F1 sample is more organized at the molecular level, while the F3 and F5 samples are similar in amorphicity and in the molecular packing. (author)

  15. Retention of Cationic Starch onto Cellulose Fibres

    Science.gov (United States)

    Missaoui, Mohamed; Mauret, Evelyne; Belgacem, Mohamed Naceur

    2008-08-01

    Three methods of cationic starch titration were used to quantify its retention on cellulose fibres, namely: (i) the complexation of CS with iodine and measurement of the absorbency of the ensuing blue solution by UV-vis spectroscopy; (ii) hydrolysis of the starch macromolecules followed by the conversion of the resulting sugars to furan-based molecules and quantifying the ensuing mixture by measuring their absorbance at a Ι of 490 nm, using the same technique as previous one and; finally (iii) hydrolysis of starch macromolecules by trifluoro-acetic acid and quantification of the sugars in the resulting hydrolysates by high performance liquid chromatography. The three methods were found to give similar results within the range of CS addition from 0 to 50 mg per g of cellulose fibres.

  16. Plantain starch granules morphology, crystallinity, structure transition, and size evolution upon acid hydrolysis.

    Science.gov (United States)

    Hernández-Jaimes, C; Bello-Pérez, L A; Vernon-Carter, E J; Alvarez-Ramirez, J

    2013-06-01

    Plantain native starch was hydrolysed with sulphuric acid for twenty days. Hydrolysis kinetics was described by a logistic function, with a zero-order rate during the first seven days, followed by a slower kinetics dynamics at longer times. X-ray diffraction results revealed a that gradual increase in crystallinity occurred during the first seven days, followed by a decrease to values similar to those found in the native starch. Differential scanning calorimetry analysis suggested a sharp structure transition by the seventh day probably due to a molecular rearrangement of the starch blocklets and inhomogeneous erosion of the amorphous regions and semi crystalline lamellae. Scanning electron micrographs showed that starch granules morphology was continually degraded from an initial oval-like shape to irregular shapes due to aggregation effects. Granule size distribution broadened as hydrolysis time proceeded probably due to fragmentation and agglomeration phenomena of the hydrolysed starch granules.

  17. Natural genetic variation in cassava (Manihot esculenta Crantz) landraces as a tool for gene discovery

    International Nuclear Information System (INIS)

    Cassava landraces are the earliest form of the modern cultivars and represents the first step in cassava domestication. Our forward genetic analysis uses this resource to discover spontaneous mutations in the sucrose/starch and carotenoid synthesis/accumulation and to develop both evolutionary and breeding perspective of gene function related to those traits. Biochemical phenotype variants for the synthesis and accumulation of carotenoid, free sugar and starch were identified. Six subtractive cDNA libraries were prepared to construct a high quality (phred > 20) EST database with 1645 entries. Macroarray analysis was performed to identify differentially expressed gene aiming to identify candidate gene related to sugary phenotype. cDNA sequence for gene coding for specific enzymes in the two pathways were obtained. Gene expression analysis for coding specific enzymes was performed by RNA blot and Real Time PCR analysis. Chromoplastassociated proteins of yellow storage root were fractionated and a peptide sequence data base with 906 entries sequences (MASCOT validated) was constructed. For the sucrose/starch metabolism a sugary class of cassava was identified carrying mutation in the BEI and GBSS mutation. For the pigmented cassava a pink color phenotype showed absence of expression of the gene CasLYB while an intense yellow phenotype showed a down regulation of the gene CasHYb. Heat shock proteins were identified as the major proteins associated with chromoplast. Genetic diversity for the GBSS gene in the natural population identified 22 haplotype and a large nucleotide diversity in four subset of population. Single segregating population derived from F2, half sib and S1 population showed segregation for sugary phenotype (93% of the individuals), waxy phenotype (38% of the individuals) and glycogen like starch (2% of the individuals). Here we summarize our current results for the genetic analysis of this variants and recent progress in the direction of mapping of

  18. Natural Genetic Variation in Cassava (Manihot esculenta Crantz) Landraces: A Tool for Gene Discovery

    International Nuclear Information System (INIS)

    Cassava landraces are the earliest form of the modern cultivars and represent the first step in cassava domestication. Our forward genetic analysis uses this resource to discover spontaneous mutations in the sucrose/ starch and carotenoid synthesis/accumulation and to develop both an evolutionary and breeding perspective of gene function related to those traits. Biochemical phenotype variants for the synthesis and accumulation of carotenoid, free sugar and starch were identified. Six subtractive cDNA libraries were prepared to construct a high quality (phred > 20) EST database with 1,645 entries. Macroarray and micro-array analysis was performed to identify differentially expressed genes aiming to identify candidate genes related to sugary phenotype and carotenoid diversity. cDNA sequence for gene coding for specific enzymes in the two pathways was obtained. Gene expression analysis for coding specific enzymes was performed by RNA blot and Real Time PCR analysis. Chromoplast-associated proteins of yellow storage root were fractionated and a peptide sequence database with 906 entries sequences (MASCOT validated) was constructed. For the sucrose/starch, metabolism a sugary class of cassava was identified, carrying a mutation in the BEI and GBSS genes. For the pigmented cassava, a pink color phenotype showed absence of expression of the gene CasLYB, while an intense yellow phenotype showed a down regulation of the gene CasHYb. Heat shock proteins were identified as the major proteins associated with carotenoid. Genetic diversity for the GBSS gene in the natural population identified 22 haplotypes and a large nucleotide diversity in four subsets of population. Single segregating population derived from F2, half-sibling and S1 population showed segregation for sugary phenotype (93% of individuals), waxy phenotype (38% of individuals) and glycogen like starch (2% of individuals). Here we summarize our current results for the genetic analysis of these variants and recent

  19. Biofuels and Biotechnology: Cassava (Manihot esculenta) as a Research Model

    International Nuclear Information System (INIS)

    Fuels such as ethanol and biodiesel, obtained from plants and their constituents, have recently received the world's attention as a true alternative to the global energy supply, mainly because they are cheaper and less contaminant of the environment than the currently used, non-renewable fossil fuels. Due to the pushing biofuel market, the world is currently experiencing an increase of agricultural land devoted to grow crops used to obtain them, like maize and sugar cane, as well as crops that have the potential to become new sources of biofuels. Similarly, this emerging market is boosting the basic research oriented towards obtaining better quality and yield in these crops. Plants that store high quantities of starch, simple sugars or oils, are the target of the biofuel industry, although the newest technologies use also cellulose as raw material to produce fuels. Cassava (Manihot esculenta) is widely grown in the tropics and constitutes a staple food for approximately 10% of the world population. The high starch content of its storage roots, together with the use of conventional and non-conventional breeding turn this crop into an option to obtain better adapted varieties for ethanol production. This manuscript reviews the current state of biofuels worldwide and at the national level,and discusses the benefits and challenges faced in terms of effect on the environment and the human food chain. Finally, it discusses the potential of cassava as a source of raw material for obtaining biofuels in Colombia.

  20. Biofuels and Biotechnology: Cassava (Manihot esculenta) as a Research Model

    International Nuclear Information System (INIS)

    Fuels such as ethanol and biodiesel, obtained from plants and their constituents, have recently received the world's attention as a true alternative to the global energy supply, mainly because they are cheaper and less contaminant of the environment than the currently used, non-renewable fossil fuels. Due to the pushing biofuel market, the world is currently experiencing an increase of agricultural land devoted to grow crops used to obtain them, like maize and sugar cane, as well as crops that have the potential to become new sources of biofuels. Similarly, this emerging market is boosting the basic research oriented towards obtaining better quality and yield in these crops. Plants that store high quantities of starch, simple sugars or oils, are the target of the biofuel industry, although the newest technologies use also cellulose as raw material to produce fuels. Cassava (Manihot esculenta) is widely grown in the tropics and constitutes a staple food for approximately 10% of the world population. The high starch content of its storage roots, together with the use of conventional and non-conventional breeding turn this crop into an option to obtain better adapted varieties for ethanol production. This manuscrip reviews the current state of biofuels worldwide and at the national level, and discusses the benefits and challenges faced in terms of effect on the environment and the human food chain. Finally, it discusses the potential of cassava as a source of raw material for obtaining biofuels in Colombia.

  1. Cloning and characterization of a tuberous root-specific promoter from cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Koehorst-van Putten, Herma J J; Wolters, Anne-Marie A; Pereira-Bertram, Isolde M; van den Berg, Hans H J; van der Krol, Alexander R; Visser, Richard G F

    2012-12-01

    In order to obtain a tuberous root-specific promoter to be used in the transformation of cassava, a 1,728 bp sequence containing the cassava granule-bound starch synthase (GBSSI) promoter was isolated. The sequence proved to contain light- and sugar-responsive cis elements. Part of this sequence (1,167 bp) was cloned into binary vectors to drive expression of the firefly luciferase gene. Cassava cultivar Adira 4 was transformed with this construct or a control construct in which the luciferase gene was cloned behind the 35S promoter. Luciferase activity was measured in leaves, stems, roots and tuberous roots. As expected, the 35S promoter induced luciferase activity in all organs at similar levels, whereas the GBSSI promoter showed very low expression in leaves, stems and roots, but very high expression in tuberous roots. These results show that the cassava GBSSI promoter is an excellent candidate to achieve tuberous root-specific expression in cassava.

  2. Expression Profiling of Cassava Storage Roots Reveals an Active Process of Glycolysis/Gluconeogenesis

    Institute of Scientific and Technical Information of China (English)

    Jun Yang; Dong An; Peng Zhang

    2011-01-01

    Mechanisms related to the development of cassava storage roots and starch accumulation remain largely unknown. To evaluate genome-wide expression patterns during tuberization, a 60 mer oligonucleotide microarray representing 20 840 cassava genes was designed to identify differentially expressed transcripts in fibrous roots, developing storage roots and mature storage roots. Using a random variance model and the traditional twofold change method for statistical analysis, 912 and 3 386 upregulated and downregulated genes related to the three developmental phases were identified. Among 25 significantly changed pathways identified, glycolysislgluconeogenesis was the most evident one. Rate-limiting enzymes were identified from each individual pathway, for example, enolase, L-lactate dehydrogenase and aldehyde dehydrogenase for glycolysis/gluconeogenesis, and ADP-glucose pyrophosphorylase, starch branching enzyme and glucan phosphorylase for sucrose and starch metabolism. This study revealed that dynamic changes in at least 16% of the total transcripts, including transcription fac-tors, oxidoreductasesltransferaseslhydrolases, hormone-related genes, and effectors of homeostasis. The reliability of these differentially expressed genes was verified by quantitative real-time reverse transcription-polymerase chain reaction. These studies should facilitate our understanding of the storage root formation and cassava improvement.

  3. An evaluation of cassava, sweet potato and field corn as potential carbohydrate sources for bioethanol production in Alabama and Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Ziska, Lewis H.; Tomecek, Martha; Sicher, Richard [United States Department of Agriculture, Agricultural Research Service, Crop Systems and Global Change Lab, 10300 Baltimore Avenue, Building 1, Beltsville, MD 20705 (United States); Runion, G. Brett; Prior, Stephen A.; Torbet, H. Allen [United States Department of Agriculture, Agricultural Research Service, National Soil Dynamics Laboratory, 411 South Donahue Drive, Auburn, AL 36832 (United States)

    2009-11-15

    The recent emphasis on corn production to meet the increasing demand for bioethanol has resulted in trepidation regarding the sustainability of the global food supply. To assess the potential of alternative crops as sources of bioethanol production, we grew sweet potato (Ipomoea batatas) and cassava (Manihot esculentum) at locations near Auburn, Alabama and Beltsville, Maryland in order to measure root carbohydrate (starch, sucrose, glucose) and root biomass. Averaged for both locations, sweet potato yielded the highest concentration of root carbohydrate (ca 80%), primarily in the form of starch (ca 50%) and sucrose (ca 30%); whereas cassava had root carbohydrate concentrations of (ca 55%), almost entirely as starch. For sweet potato, overall carbohydrate production was 9.4 and 12.7 Mg ha{sup -1} for the Alabama and Maryland sites, respectively. For cassava, carbohydrate production in Maryland was poor, yielding only 2.9 Mg ha{sup -1}. However, in Alabama, carbohydrate production from cassava averaged {proportional_to}10 Mg ha{sup -1}. Relative to carbohydrate production from corn in each location, sweet potato and cassava yielded approximately 1.5 x and 1.6 x as much carbohydrate as corn in Alabama; 2.3 x and 0.5 x for the Maryland site. If economical harvesting and processing techniques could be developed, these data suggest that sweet potato in Maryland, and sweet potato and cassava in Alabama, have greater potential as ethanol sources than existing corn systems, and as such, could be used to replace or offset corn as a source of biofuels. (author)

  4. Effect of Cassava Flour Characteristics on Properties of Cassava-Wheat-Maize Composite Bread Types

    OpenAIRE

    Maria Eduardo; Ulf Svanberg; Jorge Oliveira; Lilia Ahrné

    2013-01-01

    Replacement of wheat flour by other kinds of flour in bread making is economically important in South East Africa as wheat is mainly an imported commodity. Cassava is widely available in the region, but bread quality is impaired when large amounts of cassava are used in the bread formulation. Effect of differently processed cassavas (sun-dried, roasted and fermented) on composite cassava-wheat-maize bread quality containing cassava levels from 20 to 40% (w/w) was evaluated in combination with...

  5. Development of cassava cake enriched with its own bran and Spirulina platensis - doi: 10.4025/actascitechnol.v34i4.10687

    Directory of Open Access Journals (Sweden)

    Meire Franci Polonio Navacchi

    2012-10-01

    Full Text Available The cassava cake was developed enriching it with a biomass of Spirulina platensis and a type of bran made out of its own starch. This biomass, a part from being rich in protein, also contains vitamins, essential fatty acids and minerals. Around Umuarama, in the State of Paraná, there is an agricultural/industrial complex annually producing and processing tons of cassava. Baked goods can be elaborated based in cassava as a way to expand the use of this raw material and to produce food free of gluten to celiac people. In this complex a solid byproduct is generated, which is rich in starch and fibres, and because of its low commercial value it is used for animal feed or discarded. The bran was dehydrated and analysed microbiologically as well as physically and chemically so as to be used in applied research. Developed energetic food based on cassava lacks protein, but this can be supplied by adding the biomass of Spirulina platensis. Different formulations of this cassava cake were developed varying the concentration of Spirulina platensis and cassava bran. The formulation that presented the best features received chocolate before being submitted to sensory tests by children in the public education system. The results show an excellent acceptance which made viable the development of this product because of aspects like nutrition, technology and sensorial.

  6. Phenotypic Approaches to Drought in Cassava: Review

    OpenAIRE

    Emmanuel eOkogbenin; SETTER, TIM L.; Morag eFerguson; Rose eMutegi; Hernan eCeballos; Bunmi eOlasanmi; Martin eFregene

    2013-01-01

    Cassava is an important crop in Africa, Asia, Latin America and the Caribbean. Cassava can be produced adequately in drought conditions making it the ideal food security crop in marginal environments. Although cassava can tolerate drought stress, it can be genetically improved to enhance productivity in such environments. Drought adaptation studies in over three decades in cassava have identified relevant mechanisms which have been explored in conventional breeding. Drought is a quantitativ...

  7. Phenotypic approaches to drought in cassava: review

    OpenAIRE

    Okogbenin, Emmanuel; SETTER, TIM L.; Ferguson, Morag; Mutegi, Rose; Ceballos, Hernan; Olasanmi, Bunmi; Fregene, Martin

    2013-01-01

    Cassava is an important crop in Africa, Asia, Latin America, and the Caribbean. Cassava can be produced adequately in drought conditions making it the ideal food security crop in marginal environments. Although cassava can tolerate drought stress, it can be genetically improved to enhance productivity in such environments. Drought adaptation studies in over three decades in cassava have identified relevant mechanisms which have been explored in conventional breeding. Drought is a quantitative...

  8. Exploiting the Combination of Natural and Genetically Engineered Resistance to Cassava Mosaic and Cassava Brown Streak Viruses Impacting Cassava Production in Africa

    OpenAIRE

    Hervé Vanderschuren; Isabel Moreno; Anjanappa, Ravi B.; Ima M Zainuddin; Wilhelm Gruissem

    2012-01-01

    Cassava brown streak disease (CBSD) and cassava mosaic disease (CMD) are currently two major viral diseases that severely reduce cassava production in large areas of Sub-Saharan Africa. Natural resistance has so far only been reported for CMD in cassava. CBSD is caused by two virus species, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). A sequence of the CBSV coat protein (CP) highly conserved between the two virus species was used to demonstrate that a CBSV...

  9. Cassava is not a goitrogen in mice

    International Nuclear Information System (INIS)

    To examine the effect of cassava on the thyroid function of mice, the authors fed fresh cassava root to mice and compared this diet with low iodine diet and Purina. Cassava provided a low iodine intake and increased urine thiocyanate excretion and serum thiocyanate levels. Mice on cassava lost weight. The thyroid glands of mice on cassava were not enlarged, even when normalized for body weight. The 4- and 24-hr thyroid uptakes of mice on cassava were similar to those of mice on low iodine diets. Protein-bound [125I]iodine at 24 hr was high in mice on either the cassava or low iodine diets. The thyroid iodide trap (T/M) was similar in mice on cassava and low iodine diets. When thiocyanate was added in vitro to the incubation medium, T/M was reduced in all groups of mice; under these conditions, thiocyanate caused a dose-related inhibition of T/M. The serum thyroxine (T4) and triiodothyronine (T3) concentrations of mice on cassava were reduced compared with mice on Purina diet. Thyroid T4 and T3 contents of mice on cassava were relatively low compared with mice on Purina diet. Hepatic T3 content and T4 5'-monodeiodination in liver homogenates were reduced in mice on cassava compared with other groups. The data show that cassava does not cause goiter in mice. The thiocyanate formed from ingestation of cassava is insufficient to inhibit thyroid iodide transport or organification of iodide. The cassava diet leads to rapid turnover of hormonal iodine because it is a low iodine diet. It also impairs 5'-monodeiodination of T4 which may be related to nutritional deficiency. These data in mice do not support the concept that cassava per se has goitrogenic action in man

  10. 不同淀粉对速冻卡通鸡块的品质影响研究%Study on effect of different starch on quality of quick-frozen cartoon chicken

    Institute of Scientific and Technical Information of China (English)

    王杨; 刘欣; 张萍

    2015-01-01

    以速冻卡通鸡块为研究对象,通过对比相同添加量的玉米淀粉、豌豆淀粉、马铃薯淀粉和木薯淀粉在对鸡块品质的影响发现:添加四种淀粉的产品在色泽、滋气味、手感和口感方面差异性不显著;在改善鸡块的弹性方面,木薯淀粉和马铃薯淀粉显著优于豌豆淀粉与玉米淀粉,其中木薯淀粉效果最好。%Quick-frozen cartoon chicken was taken as an object of study. The effects of different addition of the corn starch, pea starch, potato starch and cassava starch on the quality of chicken nuggets were compared. The results showed that there was no significant difference in color, smell, feel and taste of the products added with the four kinds of starches respectively. In the aspect of improving the elasticity of the chicken nuggets, cassava starch and potato starch were obviously better than the pea starch and corn starch. Among them the effect of cassava starch was best.

  11. Hyperphosphorylation of cereal starch

    DEFF Research Database (Denmark)

    Carciofi, Massimiliano; Shaik, Shahnoor Sultana; Jensen, Susanne Langgård;

    2011-01-01

    phosphate compared with potato tuber starch and in order to investigate the effect of increased endosperm starch phosphate, the potato starch phosphorylating enzyme glucan water dikinase (StGWD) was overexpressed specifically in the developing barley endosperm. StGWD overexpressors showed wild......Plant starch is naturally phosphorylated at a fraction of the C6 and the C3 hydroxyl groups during its biosynthesis in plastids. Starch phosphate esters are important in starch metabolism and they also generate specific industrial functionality. Cereal grains starch contains little starch bound......-type phenotype. Transgenic cereal grains synthesized starch with higher starch bound phosphate content (7.5 (±0.67) nmol/mg) compared to control lines (0.8 (±0.05) nmol/mg) with starch granules showing altered morphology and lower melting enthalpy. Our data indicate specific action of GWD during starch...

  12. Mutan produced in potato amyloplasts adheres to starch granules.

    Science.gov (United States)

    Kok-Jacon, Géraldine A; Vincken, Jean-Paul; Suurs, Luc C J M; Visser, Richard G F

    2005-05-01

    Production of water-insoluble mutan polymers in Kardal potato tubers was investigated after expression of a full-length (GtfI) and a truncated mutansucrase gene referred to as GtfICAT (GtfI without glucan-binding domain) from Streptococcus downei. Subsequent effects on starch biosynthesis at the molecular and biochemical levels were studied. Expression of the GtfICAT gene resulted in the adhesion of mutan material on starch granules, which stained red with erythrosine, and which was hydrolysed by exo-mutanase. In addition, GtfICAT-expressing plants exhibited a severely altered tuber phenotype and starch granule morphology in comparison to those expressing the full-length GtfI gene. In spite of that, no structural changes at the starch level were observed. Expression levels of the sucrose-regulated, AGPase and GBSSI genes were down-regulated in only the GTFICAT transformants, showing that GtfICAT expression interfered with the starch biosynthetic pathway. In accordance with the down-regulated AGPase gene, a lower starch content was observed in the GTFICAT transformants. Finally, the rheological properties of the GTFICAT starches were modified; they showed a higher retrogradation during cooling of the starch paste. PMID:17129316

  13. Substituição do milho pelo resíduo de fecularia de mandioca sobre o desempenho, digestibilidade e características de carcaça de novilhos confinados - DOI: 10.4025/actascianimsci.v31i4.6093 Replacing corn with cassava starch by-products on the performance, digestibility and carcass characteristics of bulls in confinement - DOI: 10.4025/actascianimsci.v31i4.6093

    Directory of Open Access Journals (Sweden)

    Maribel Velandia Valero

    2009-10-01

    Full Text Available O efeito de substituição do milho pelo resíduo desidratado de fecularia de mandioca (0; 12,5; 22,8 e 32,7% foi avaliado sobre o desempenho, a digestibilidade e características de carcaça e 32 bovinos mestiços (½ Nelore x ½ Angus de aproximadamente 18 meses de idade e 380 kg de peso vivo. O delineamento experimental foi o inteiramente casualizado, com quatro tratamentos e oito repetições. Foram analisados o ganho médio diário (GMD, rendimento de carcaça (RC, espessura de gordura de cobertura (EGC, área de olho de lombo (AOL, comprimento de perna (CP, espessura de coxão (EC, ingestão de matéria seca (IMS, conversão alimentar (CA, digestibilidade total aparente da matéria seca (DAMS, matéria orgânica (DAMO, proteína bruta (DAPB, energia bruta (DAEB, fibra em detergente ácido (DAFDA e fibra em detergente neutro (DAFDN. O experimento foi desenvolvido durante um período de 56 dias, após 14 dias de adaptação. Os resultados de GMD, RC, CA, EGC, AOL, CP e EC não apresentaram diferenças (p > 0,05 entre os tratamentos. A IMS apresentou redução linear quando o milho foi substituído pelo resíduo desidratado de fecularia de mandioca. Os coeficientes de digestibilidade da MS, MO, PB, EB, FDN e FDA não variaram entre as rações experimentais.The effects of replacing corn with different levels of cassava starch by-products (0, 12.5, 22.8, and 32.7% were evaluated on performance, digestibility and carcass traits of feedlot bulls. Thirty-two crossbred bulls (½ Nelore x ½ Angus around 18 months of age and 380 kg of body weight were used. A completely randomized design was used, with 4 treatments and 8 replicates. Evaluated traits were: average daily gain (ADG, carcass dressing (CD, backfat thickness (BT, Longissimus area (LDA, leg length (LL and cushion thickness (CT, dry matter intake (DMI, feed conversion ratio (FCR, total apparent digestibility of dry matter (DMDC, organic matter (OMDC, crude protein (CPDC, crude energy (CEDC

  14. Physicochemical characterization of natural and acetylated thermoplastic cassava starch

    OpenAIRE

    JOSE MINA; ALEX VALADEZ-GONZÁLEZ; PEDRO HERRERA-FRANCO; FABIO ZULUAGA; SILVIO DELVASTO

    2011-01-01

    Almidón de Yuca natural y acetilado fueron plastifi cados empleando un extrusor de doble husillo y almacenados a 25 °C y 54 % de humedad relativa. El índice de cristalinidad, estimado como el cociente de las bandas de FTIR a 1047 (fase cristalina) y a 1022 cm-1 (fase amorfa) disminuyó en ambos almidones debido al proceso de plastifi cación. Mediante las micrografías de SEM se pudo observar que el proceso de plastifi cación destruyó casi por completo la estructura granular de los almidones. Lo...

  15. Effect of Cassava Flour Characteristics on Properties of Cassava-Wheat-Maize Composite Bread Types

    Directory of Open Access Journals (Sweden)

    Maria Eduardo

    2013-01-01

    Full Text Available Replacement of wheat flour by other kinds of flour in bread making is economically important in South East Africa as wheat is mainly an imported commodity. Cassava is widely available in the region, but bread quality is impaired when large amounts of cassava are used in the bread formulation. Effect of differently processed cassavas (sun-dried, roasted and fermented on composite cassava-wheat-maize bread quality containing cassava levels from 20 to 40% (w/w was evaluated in combination with high-methylated pectin (HM-pectin added at levels of 1 to 3% (w/w according to a full factorial design. Addition of pectin to cassava flour made it possible to bake bread with acceptable bread quality even at concentration as high as 40%. In addition to cassava concentration, the type of cassava flour had the biggest effect on bread quality. With high level of cassava, bread with roasted cassava had a higher volume compared with sun-dried and fermented. The pectin level had a significant effect on improving the volume in high level roasted cassava bread. Crumb firmness similar to wheat bread could be obtained with sun-dried and roasted cassava flours. Roasted cassava bread was the only bread with crust colour similar to wheat bread.

  16. Sensorial evolution of cassava flour (Manihot esculenta crantz) added to protein concentrate cassava leaves.

    Science.gov (United States)

    Lima, Elaine C S; Feijo, Márcia B S; Freitas, Maria C J; Dos Santos, Edna R; Sabaa-Srur, Armando U O; Moura, Luciana S M

    2013-09-01

    Cassava is regarded as the nutritional base of populations in developing countries, and flour, product made of cassava, is the most consumed in the world. The cassava leaves are very rich in vegetable proteins, but a big amount is lost in processing the crop. The objective of this study was to do a sensory evaluation of cassava flour to which a protein concentrate obtained from cassava leaves (CPML) was added. The CPML was obtained from cassava leaves by isoelectric precipitation and added to cassava paste for preparation of flour in three parts 2.5, 5, and 10%. The acceptance test was done by 93 consumers of flour, using hedonic scale of 7 points to evaluate characteristics like color, scent, flavor, bitterness, texture, and overall score. By the method of quantitative descriptive analysis (QDA), eight trained tasters evaluated the following characteristics: whitish color, greenish color, cassava flavor, bitter flavor, characteristic flavor, lumpiness, raw texture, leaf scent, and cassava scent. The acceptability test indicated that flour cassava with 2.5 was preferred. Whitish color, greenish color, cassava flavor, bitter flavor, salty flavor, characteristic flavor, lumpiness texture, raw texture, and the smell of the leaves and cassava flour were the main descriptors defined for flour cassava with CPML has better characteristics. PMID:24804041

  17. Sensorial evolution of cassava flour (Manihot esculenta crantz) added to protein concentrate cassava leaves.

    Science.gov (United States)

    Lima, Elaine C S; Feijo, Márcia B S; Freitas, Maria C J; Dos Santos, Edna R; Sabaa-Srur, Armando U O; Moura, Luciana S M

    2013-09-01

    Cassava is regarded as the nutritional base of populations in developing countries, and flour, product made of cassava, is the most consumed in the world. The cassava leaves are very rich in vegetable proteins, but a big amount is lost in processing the crop. The objective of this study was to do a sensory evaluation of cassava flour to which a protein concentrate obtained from cassava leaves (CPML) was added. The CPML was obtained from cassava leaves by isoelectric precipitation and added to cassava paste for preparation of flour in three parts 2.5, 5, and 10%. The acceptance test was done by 93 consumers of flour, using hedonic scale of 7 points to evaluate characteristics like color, scent, flavor, bitterness, texture, and overall score. By the method of quantitative descriptive analysis (QDA), eight trained tasters evaluated the following characteristics: whitish color, greenish color, cassava flavor, bitter flavor, characteristic flavor, lumpiness, raw texture, leaf scent, and cassava scent. The acceptability test indicated that flour cassava with 2.5 was preferred. Whitish color, greenish color, cassava flavor, bitter flavor, salty flavor, characteristic flavor, lumpiness texture, raw texture, and the smell of the leaves and cassava flour were the main descriptors defined for flour cassava with CPML has better characteristics.

  18. Commercial Dynamics in Zambia’s Cassava Value Chain

    OpenAIRE

    Haggblade, Steven; Nyembe, Misheck

    2008-01-01

    Cassava production has grown rapidly in Zambia since the early 1990’s. Available evidence suggests that volumes of traded cassava have been increasing roughly twice as fast as production. Yet this cassava production boom could stall unless commercial markets for it develop. To help accelerate commercial development of cassava and cassava-based products at the national level, Zambia’s Agricultural Consultative Forum (ACF) initiated an Acceleration of Cassava Utilization (ACU) Task Force, begin...

  19. Induction and identification of useful mutations for root quality traits in cassava

    International Nuclear Information System (INIS)

    Cassava is an important crop in tropical and subtropical countries. There is little reported variation for root quality traits. Roots spoil 1-2 days after harvest because of a process known as of post-harvest physiological deterioration (PPD). These two problems limit the impact of this crop to help farmers out of poverty. Cassava seeds were irradiated with gamma rays or fast neutrons. They were germinated and the M1 plants transplanted to the field and self-pollinated to produce M2 seed. Approximately 1500 M2 plants were harvested, about 800 produced roots, and 38 of them were selected because they showed special characteristics. Best results were obtained with gamma rays (200 Gy from Cobalt 60). Results originally observed in the M2 genotypes were confirmed in the cloned plants. Two of these mutations will be described here. The first mutation produced a starch whose granules were half the size compared with that of wild type cassava. Interestingly, this phenotype was observed in self-pollinated progenies from two different M1 plants. In one case, three M2-genotypes derived from the same M1 plant expressed this mutation, indicating a genetic origin. Starch had higher than normal amylose content, the gels it produces did not show any viscosity and had low clarity. Most likely this mutation affected one of the isoamylase genes. The small granule size could be useful for bio-ethanol production (reduced need of degrading enzymes) but the higher levels of amylose may neutralize this advantage. High-amylose starches have commercial advantages and are known as 'resistant starches'. The second mutation involves reduced PPD. Roots were kept for almost three weeks without PPD. Results need further confirmation based on larger number of roots. Most likely the mutation affected one of the self-defense mechanism genes related to PPD. This mutation could have large impact in poverty alleviation. (author)

  20. The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration.

    Science.gov (United States)

    Uarrota, Virgílio Gavicho; Moresco, Rodolfo; Schmidt, Eder Carlos; Bouzon, Zenilda Laurita; Nunes, Eduardo da Costa; Neubert, Enilto de Oliveira; Peruch, Luiz Augusto Martins; Rocha, Miguel; Maraschin, Marcelo

    2016-04-15

    This study aimed to investigate the role of ascorbate peroxidase (APX), guaiacol peroxidase (GPX), polysaccharides, and protein contents associated with the early events of postharvest physiological deterioration (PPD) in cassava roots. Increases in APX and GPX activity, as well as total protein contents occurred from 3 to 5 days of storage and were correlated with the delay of PPD. Cassava samples stained with Periodic Acid-Schiff (PAS) highlighted the presence of starch and cellulose. Degradation of starch granules during PPD was also detected. Slight metachromatic reaction with toluidine blue is indicative of increasing of acidic polysaccharides and may play an important role in PPD delay. Principal component analysis (PCA) classified samples according to their levels of enzymatic activity based on the decision tree model which showed GPX and total protein amounts to be correlated with PPD. The Oriental (ORI) cultivar was more susceptible to PPD.

  1. The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration.

    Science.gov (United States)

    Uarrota, Virgílio Gavicho; Moresco, Rodolfo; Schmidt, Eder Carlos; Bouzon, Zenilda Laurita; Nunes, Eduardo da Costa; Neubert, Enilto de Oliveira; Peruch, Luiz Augusto Martins; Rocha, Miguel; Maraschin, Marcelo

    2016-04-15

    This study aimed to investigate the role of ascorbate peroxidase (APX), guaiacol peroxidase (GPX), polysaccharides, and protein contents associated with the early events of postharvest physiological deterioration (PPD) in cassava roots. Increases in APX and GPX activity, as well as total protein contents occurred from 3 to 5 days of storage and were correlated with the delay of PPD. Cassava samples stained with Periodic Acid-Schiff (PAS) highlighted the presence of starch and cellulose. Degradation of starch granules during PPD was also detected. Slight metachromatic reaction with toluidine blue is indicative of increasing of acidic polysaccharides and may play an important role in PPD delay. Principal component analysis (PCA) classified samples according to their levels of enzymatic activity based on the decision tree model which showed GPX and total protein amounts to be correlated with PPD. The Oriental (ORI) cultivar was more susceptible to PPD. PMID:26617011

  2. Cassava virus diseases: biology, epidemiology, and management.

    Science.gov (United States)

    Legg, James P; Lava Kumar, P; Makeshkumar, T; Tripathi, Leena; Ferguson, Morag; Kanju, Edward; Ntawuruhunga, Pheneas; Cuellar, Wilmer

    2015-01-01

    Cassava (Manihot esculenta Crantz.) is the most important vegetatively propagated food staple in Africa and a prominent industrial crop in Latin America and Asia. Its vegetative propagation through stem cuttings has many advantages, but deleteriously it means that pathogens are passed from one generation to the next and can easily accumulate, threatening cassava production. Cassava-growing continents are characterized by specific suites of viruses that affect cassava and pose particular threats. Of major concern, causing large and increasing economic impact in Africa and Asia are the cassava mosaic geminiviruses that cause cassava mosaic disease in Africa and Asia and cassava brown streak viruses causing cassava brown streak disease in Africa. Latin America, the center of origin and domestication of the crop, hosts a diverse set of virus species, of which the most economically important give rise to cassava frog skin disease syndrome. Here, we review current knowledge on the biology, epidemiology, and control of the most economically important groups of viruses in relation to both farming and cultural practices. Components of virus control strategies examined include: diagnostics and surveillance, prevention and control of infection using phytosanitation, and control of disease through the breeding and promotion of varieties that inhibit virus replication and/or movement. We highlight areas that need further research attention and conclude by examining the likely future global outlook for virus disease management in cassava.

  3. Comparative physiological and transcriptomic analyses reveal the actions of melatonin in the delay of postharvest physiological deterioration of cassava

    Directory of Open Access Journals (Sweden)

    Wei eHu

    2016-05-01

    Full Text Available Melatonin plays important roles in various aspects of biological processes. However, it is less known on the effects and mechanism of melatonin on the postharvest physiological deterioration (PPD process of cassava, which largely restricts the potential of cassava as a food and industrial crop. In this study, we found that exogenous application of melatonin significantly delayed PPD of cassava tuberous roots by reducing H2O2 content and improving activities of catalase and peroxidase. Moreover, 3425 differentially expressed genes by melatonin during the PPD process were identified by transcriptomic analysis. Several pathways were markedly affected by melatonin treatments, including metabolic-, ion homeostasis-, and enzyme activity-related processes. Further detailed analysis revealed that melatonin acted through activation of ROS-scavenging and ROS signal transduction pathways, including antioxidant enzymes, calcium signaling, MAPK cascades, and transcription factors at early stages. Notably, the starch degradation pathway was also activated at early stages, whereas it was repressed by melatonin at middle and late stages, thereby indicating its regulatory role in starch metabolism during PPD. Taken together, this study yields new insights into the effect and underlying mechanism of melatonin on the delay of PPD and provides a good strategy for extending shelf life and improvement of cassava tuberous roots.

  4. Comparative Physiological and Transcriptomic Analyses Reveal the Actions of Melatonin in the Delay of Postharvest Physiological Deterioration of Cassava

    Science.gov (United States)

    Hu, Wei; Kong, Hua; Guo, Yunling; Zhang, Yuliang; Ding, Zehong; Tie, Weiwei; Yan, Yan; Huang, Qixing; Peng, Ming; Shi, Haitao; Guo, Anping

    2016-01-01

    Melatonin plays important roles in various aspects of biological processes. However, it is less known on the effects and mechanism of melatonin on the postharvest physiological deterioration (PPD) process of cassava, which largely restricts the potential of cassava as a food and industrial crop. In this study, we found that exogenous application of melatonin significantly delayed PPD of cassava tuberous roots by reducing H2O2 content and improving activities of catalase and peroxidase. Moreover, 3425 differentially expressed genes by melatonin during the PPD process were identified by transcriptomic analysis. Several pathways were markedly affected by melatonin treatments, including metabolic-, ion homeostasis-, and enzyme activity-related processes. Further detailed analysis revealed that melatonin acted through activation of ROS-scavenging and ROS signal transduction pathways, including antioxidant enzymes, calcium signaling, MAPK cascades, and transcription factors at early stages. Notably, the starch degradation pathway was also activated at early stages, whereas it was repressed by melatonin at middle and late stages, thereby indicating its regulatory role in starch metabolism during PPD. Taken together, this study yields new insights into the effect and underlying mechanism of melatonin on the delay of PPD and provides a good strategy for extending shelf life and improvement of cassava tuberous roots. PMID:27303428

  5. Amphoteric Starch in Simultaneous Process Preparation with Box-Behnken Design for Optimal Conditions

    Directory of Open Access Journals (Sweden)

    Sopa Cansee

    2008-01-01

    Full Text Available Cassava starch was chemically modified to produce an amphoteric starch. The amphoteric starch was prepared in a simultaneous process which was evaluated in relation to four factors: temperature (45-55 °C, 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC, 4-12% and sodium tripolyphosphate (STP, 2-8% concentrations, and reaction time (2-6 h. The extent of amphoteric starch produced was determined by the degree of substitution (DS of the nitrogen content and percentage of phosphorus content. In addition, a quantitative response of yield and whiteness as well as pasting characteristics were tested. Response surface analysis showed that the DS (0.01-0.05 increased with increasing temperature, CHPTAC and reaction time. The phosphorus content (0.09-0.34% followed a parabolic shape with all of the factors. Consequently, the response surface methodology appears to be a powerful technique to determine the optimal conditions for the production of amphoteric starches.

  6. EXPLORING OPTIMAL FEED TO MICROBES RATIO FOR ANAEROBIC ACIDOGENIC FERMENTATION OF CASSAVA RESIDUE FROM BREWERY

    Directory of Open Access Journals (Sweden)

    Xinying Wang,

    2012-01-01

    Full Text Available Cassava residue from breweries is being generated in large amounts in Guangxi Province of China, and this has potential to cause serious environmental problems if disposed of improperly. Two-stage anaerobic fermentation is a promising method for the treatment of such residue. In this study, the effect of feed to microbes ratio (F/M ratio on the anaerobic acidogenic fermentation of cassava residue was studied to determine the optimal F/M ratio and to maximize the performance in a subsequent methanogenic stage. The experiments were carried out at the F/M ratios of 0.2, 0.61, 1.02, 2.05, 3.07, and 4.09 g cassava-TS/g sludge-VSS in six laboratory-scale, completely stirred, tank reactors (CSTR at mesophilic temperature (35°C. An F/M ratio of 1.02 g cassava-TS/g sludge-VSS resulted in the highest solid removal efficiency and VFA/COD ratio, while starch removal efficiency was still near 100 percent, and acidification was relatively high. As a further benefit, the VFA distribution was more suitable for the subsequent methanogenic fermentation stage.

  7. Bulk H analysis using neutrons for routine quality control of cassava and products

    Energy Technology Data Exchange (ETDEWEB)

    Jonah, S.A., E-mail: jonahsa2001@yahoo.co [Centre for Energy Research and Training, Ahmadu Bello University, Zaria (Nigeria); Okunade, I.O. [Centre for Energy Research and Training, Ahmadu Bello University, Zaria (Nigeria); Abolude, O. [Department of Physics, Ahmadu Bello University, Zaria (Nigeria); Onyike, E.; Inuwa, I.M. [Department of Biochemistry, Ahmadu Bello University, Zaria (Nigeria)

    2011-07-15

    Nuclear and related techniques are useful in addressing the issues of food security and safety facing the world today, via quality control of raw materials and products. In this work, experimental investigations were performed to assess the use of total hydrogen content in cassava and products as a quality control indicator of starch and cyanide contents. The work was carried out using a neutron reflection facility at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. Cassava samples and products were obtained from retail outlets of Ibadan, Umudike and Zaria, representing three major regions of Nigeria. In general, data obtained indicate a total hydrogen content range of 4.47{+-}0.11-10.71{+-}0.27 wt% for the various samples, including raw, dry and processed cassava. Results show that samples having low hydrogen content are generally rich in cyanide compounds and demonstrate an inverse relationship between hydrogen content and cyanide content. The implication of this is that the neutron reflection facility can be used as a quality control setup for routine determination of hydrogen as an indicator of the cyanide content in cassava and products.

  8. Bulk H analysis using neutrons for routine quality control of cassava and products

    International Nuclear Information System (INIS)

    Nuclear and related techniques are useful in addressing the issues of food security and safety facing the world today, via quality control of raw materials and products. In this work, experimental investigations were performed to assess the use of total hydrogen content in cassava and products as a quality control indicator of starch and cyanide contents. The work was carried out using a neutron reflection facility at the Centre for Energy Research and Training, Ahmadu Bello University, Zaria, Nigeria. Cassava samples and products were obtained from retail outlets of Ibadan, Umudike and Zaria, representing three major regions of Nigeria. In general, data obtained indicate a total hydrogen content range of 4.47±0.11-10.71±0.27 wt% for the various samples, including raw, dry and processed cassava. Results show that samples having low hydrogen content are generally rich in cyanide compounds and demonstrate an inverse relationship between hydrogen content and cyanide content. The implication of this is that the neutron reflection facility can be used as a quality control setup for routine determination of hydrogen as an indicator of the cyanide content in cassava and products.

  9. 黄姜渣提取淀粉的成分及颗粒结构分析%Analysis on the Composition and Structure of Starch Granules from Dioscorea zingibrensis

    Institute of Scientific and Technical Information of China (English)

    杨铖; 毛楠; 籍国东

    2011-01-01

    [Objective] The aim was to analyze the the composition and structure of starch granules from Dioscorea zingiberensis. [Method] High-quality Dioscorea zingiberensis starch was extracted from the residues of yellow ginger diosgenin processing by physical separation technology,and then the composition and structure of starch granules from Dioscorea zingiberensis was analyzed. [ Result ] The water content of Dioscorea zingiberensis starch was close to that of cassava starch; its starch purity was similar to those of cassava starch and potato starch in the market;its protein content was lower than that of cassava starch and potato starch,and lipid content was lower than that of potato starch, while its amylose content was higher than those of cassava starch and potato starch. So Dioscorea zingiberensis starch had better quality than cassava starch and potato starch. Dioscorea zingiberensis starch granules were caky ,had rough surface,larger and uniform sizes,and granules diameters were 15 -25 μm. Acid hydrolysis showed that the granule may be a hollow structure ,and the hollows alternately distributed in the crystalline region and amorphous region of the granule. [ Conclusion]The research provides reference for the application of Dioscorea zingiberensis in food industry.%[目的]分析黄姜渣提取淀粉的成分及颗粒结构.[方法]利用物理分离方法从黄姜生产皂素的废渣中提取优质黄姜淀粉,分析了其主要成分和颗粒结构.[结果]黄姜淀粉的含水量与木薯淀粉接近;其淀粉含量与木薯淀粉和马铃薯淀粉接近;其蛋白质含量低于其他2种淀粉;其脂肪含量低于马铃薯淀粉;其直链淀粉含量则高于其他2种淀粉,品质更优.SEM分析表明,黄姜淀粉颗粒呈饼状,表面较粗糙,颗粒较大且较均匀,粒径在15~25 μm.酸水解分析表明,黄姜淀粉颗粒可能为中空的,且在颗粒内部结晶区和无定形区是交替分布的.[结论]该研究为黄姜淀粉在食品行业的应用提供了参考.

  10. Instant blend from cassava derivatives produced by extrusion

    Directory of Open Access Journals (Sweden)

    Fernanda Rossi Moretti Trombini

    2016-03-01

    Full Text Available ABSTRACT: The current research aimed to evaluate the effects of extrusion parameters on the physical characteristics of extruded blends of cassava leaf flour and starch. A factorial central composite design with four independent variables and the response surface methodology were used to evaluate the results of color parameters (L*, a*, b*, water absorption index, water solubility index and paste properties, according to the variations in the leaf flour percentage (1.5 to 7.5%, extrusion temperature (60 to 100ºC, screw speed (175 to 231rpm and moisture (20 to 30%. Extrusion conditions affect color, water absorption and water solubility indexes and paste properties of blends. The intermediate tested conditions of variable parameters lead to obtain extruded products with higher cold viscosity and water absorption index and light color, desirable qualities for rapid preparation products.

  11. Resistance to Sri Lankan Cassava Mosaic Virus (SLCMV) in Genetically Engineered Cassava cv. KU50 through RNA Silencing

    KAUST Repository

    Ntui, Valentine Otang

    2015-04-22

    Cassava ranks fifth among the starch producing crops of the world, its annual bioethanol yield is higher than for any other crop. Cassava cultivar KU50, the most widely grown cultivar for non-food purposes is susceptible to Sri Lankan cassava mosaic virus (SLCMV). The objective of this work was to engineer resistance to SLCMV by RNA interference (RNAi) in order to increase biomass yield, an important aspect for bioethanol production. Here, we produced transgenic KU50 lines expressing dsRNA homologous to the region between the AV2 and AV1 of DNA A of SLCMV. High level expression of dsRNA of SLCMV did not induce any growth abnormality in the transgenic plants. Transgenic lines displayed high levels of resistance to SLCMV compared to the wild-type plants and no virus load could be detected in uninoculated new leaves of the infected resistant lines after PCR amplification and RT-PCR analysis. The agronomic performance of the transgenic lines was unimpaired after inoculation with the virus as the plants presented similar growth when compared to the mock inoculated control plants and revealed no apparent reduction in the amount and weight of tubers produced. We show that the resistance is correlated with post-transcriptional gene silencing because of the production of transgene specific siRNA. The results demonstrate that transgenic lines exhibited high levels of resistance to SLCMV. This resistance coupled with the desirable yield components in the transgenic lines makes them better candidates for exploitation in the production of biomass as well as bioethanol.

  12. Resistance to Sri Lankan cassava mosaic virus (SLCMV in genetically engineered cassava cv. KU50 through RNA silencing.

    Directory of Open Access Journals (Sweden)

    Valentine Otang Ntui

    Full Text Available Cassava ranks fifth among the starch producing crops of the world, its annual bioethanol yield is higher than for any other crop. Cassava cultivar KU50, the most widely grown cultivar for non-food purposes is susceptible to Sri Lankan cassava mosaic virus (SLCMV. The objective of this work was to engineer resistance to SLCMV by RNA interference (RNAi in order to increase biomass yield, an important aspect for bioethanol production. Here, we produced transgenic KU50 lines expressing dsRNA homologous to the region between the AV2 and AV1 of DNA A of SLCMV. High level expression of dsRNA of SLCMV did not induce any growth abnormality in the transgenic plants. Transgenic lines displayed high levels of resistance to SLCMV compared to the wild-type plants and no virus load could be detected in uninoculated new leaves of the infected resistant lines after PCR amplification and RT-PCR analysis. The agronomic performance of the transgenic lines was unimpaired after inoculation with the virus as the plants presented similar growth when compared to the mock inoculated control plants and revealed no apparent reduction in the amount and weight of tubers produced. We show that the resistance is correlated with post-transcriptional gene silencing because of the production of transgene specific siRNA. The results demonstrate that transgenic lines exhibited high levels of resistance to SLCMV. This resistance coupled with the desirable yield components in the transgenic lines makes them better candidates for exploitation in the production of biomass as well as bioethanol.

  13. Resistance to Sri Lankan cassava mosaic virus (SLCMV) in genetically engineered cassava cv. KU50 through RNA silencing.

    Science.gov (United States)

    Ntui, Valentine Otang; Kong, Kynet; Khan, Raham Sher; Igawa, Tomoko; Janavi, Gnanaguru Janaky; Rabindran, Ramalingam; Nakamura, Ikuo; Mii, Masahiro

    2015-01-01

    Cassava ranks fifth among the starch producing crops of the world, its annual bioethanol yield is higher than for any other crop. Cassava cultivar KU50, the most widely grown cultivar for non-food purposes is susceptible to Sri Lankan cassava mosaic virus (SLCMV). The objective of this work was to engineer resistance to SLCMV by RNA interference (RNAi) in order to increase biomass yield, an important aspect for bioethanol production. Here, we produced transgenic KU50 lines expressing dsRNA homologous to the region between the AV2 and AV1 of DNA A of SLCMV. High level expression of dsRNA of SLCMV did not induce any growth abnormality in the transgenic plants. Transgenic lines displayed high levels of resistance to SLCMV compared to the wild-type plants and no virus load could be detected in uninoculated new leaves of the infected resistant lines after PCR amplification and RT-PCR analysis. The agronomic performance of the transgenic lines was unimpaired after inoculation with the virus as the plants presented similar growth when compared to the mock inoculated control plants and revealed no apparent reduction in the amount and weight of tubers produced. We show that the resistance is correlated with post-transcriptional gene silencing because of the production of transgene specific siRNA. The results demonstrate that transgenic lines exhibited high levels of resistance to SLCMV. This resistance coupled with the desirable yield components in the transgenic lines makes them better candidates for exploitation in the production of biomass as well as bioethanol.

  14. Marker-assisted selection in common beans and cassava

    International Nuclear Information System (INIS)

    (CGM) and cassava brown streak (CBS) resistance from a wild relative, M. esculenta sub spp. flabellifolia. The use of advanced backcrossing with additional wild relatives is proposed as a way to discover genes for high protein content, waxy starch, delayed post-harvest physiological deterioration, and resistance to whiteflies and hornworm. Other potential targets of MAS such as beta carotene and dry matter content as well as lower cyanogenic potential are given. In addition, suggestions are made for the use of molecular markers to estimate average heterozygosity during inbreeding of cassava and for the delineation of heterotic groups within the species. A final section describes the similarities and differences between the MAS schemes presented for the two crops. Differences between the species can be ascribed partially to the breeding and propagation systems of common beans (seed propagated, selfpollinating) and cassava (clonally propagated, cross-pollinating). In addition, differences in growth cycles, breeding methods, availability of genetic markers, access to selection environments and the accompanying opportunities for phenotypic selection influence the decisions in both crops of when and how to apply MAS. Recommendations are made for applying MAS in breeding of both crops including careful prioritization of traits, marker systems, genetic stocks, scaling up, planning of crosses and the balance between MAS and phenotypic selection. (author)

  15. Starch nanocrystals based hydrogel: Construction, characterizations and transdermal application.

    Science.gov (United States)

    Bakrudeen, Haja Bava; Sudarvizhi, C; Reddy, B S R

    2016-11-01

    Bio-based nanocomposites were prepared using starch nanocrystals obtained by acid hydrolysis of native starches using different acid sources. In recent times, focuses on starch nanocrystals (SNCs) have been increasing in number of research works dedicated to the development of bio-nanocomposites by blending with different biopolymeric matrices. The work mainly deals with the preparation of starch nanocrystals using different native starches by acid hydrolysis using hydrochloric acid and trifluroacetic acid. The as-prepared starch nanocrystals are having high crystallinity and more platelet morphologies, and used as a drug carrying filler material in the hydrogel formulations with the care of different polymer matrices. The condensed work also concentrates on the dispersion of antiviral drug in the hydrogels, which are applied onto biocompatible bio-membrane to be formulating a complete transdermal patch. The acid hydrolysed starch nanocrystals were thoroughly characterized using TEM, SEM, particle size analysis and zeta potential. Their thermal stability and the crystalline properties were also characterized using TG-DSC and XRD respectively. The physiochemical interaction and compatibility between the drug and the SNCs filler in the polymeric hydrogels were evaluated using FT-IR analysis. The formulated hydrogels were subjected to evaluation of in vitro permeation studies using Franz diffusion studies. The in vitro study was indicated substantial guarantee for the fabrication of drug dispersed in polymeric hydrogels using SNCs as filler matrices for a successful transdermal drug delivery. PMID:27524091

  16. Development of Jackfruit Crackers: Effects of Starch Type and Jackfruit Level

    Directory of Open Access Journals (Sweden)

    Nor Afizah Mustapha

    2015-01-01

    Full Text Available Crackers are one of the convenient and inexpensive snacks that have high market potential.  Most of the commercial crackers are carbohydrate-rich and normally considered as a low value-added product.  In this study, innovative value added crackers made of jackfruit were developed.  The effect of starches (sago and cassava and levels of jackfruit (30 and 50%, w/w on characteristics of the crackers were investigated.  Physicochemical properties of the products at each predetermined processing steps (steaming, drying and frying; bulk density, expansion ratio, color and carotenoid contents were measured.  A decrease in jackfruit level resulted in crackers with lower bulk density (0.26 to 0.41 g/cm3 and higher volume expansion ratio (2.84 to 4.66 cm3.  Blending the cassava and sago starch at 1:1 ratio resulted in lower bulk density and higher expansion ratio compared to crackers made with a single type of starch.  The L* and b* values decreased with drying and frying process, indicative of Maillard reactions.  The higher L* value was influenced by the starch content, while higher jackfruit led increased the b* values, attributed to the presence of pigments in the fruit.  Total carotenoid contents of fried crackers increased following steaming process, ranging from 0.061 to 0.199 mg/100g and samples made with blend of sago and cassava has the highest carotenoid contents.  A jackfruit level of 30% (w/w made with blend of sago and cassava starches (1:1 produced fried crackers with the most acceptable physicochemical characteristics.  Crackers with improved nutritional value can be developed by incorporating jackfruit, thus expanding the conventional use of the fruit.

  17. Culture conditions for yellow pigment formation byMonascus sp. KB 10 grown on cassava medium.

    Science.gov (United States)

    Yongsmith, B; Tabloka, W; Yongmanitchai, W; Bavavoda, R

    1993-01-01

    An isolate ofMonascus, from a commercial, fermented soybean curd (sufu) was grown on a cassava medium. With medium at an initial pH of 7.0 an orange-red pigmentation was produced but with an initial pH below 4, a light golden pigment was obtained. A medium containing, w/v, 3% cassava starch, 0.4% peptone and 0.1% glutamic acid, with an initial pH of 2.5 was optimal for the production of this yellow pigment, which had a single maximum absorption spectrum at 330 nm. The spectroscopic characterization of the purified yellow pigments demonstrated a monascin-ankaflavin-monascorubrin skeleton.

  18. Starch for health

    OpenAIRE

    Drago Šubarić; Đurđica Ačkar; Jurislav Babić; Borislav Miličević

    2012-01-01

    It is well established that part of starch is resistant to human amylases and escapes undigested to large bowel. This fraction of starch is resistant starch. Recent studies have shown that resistant starch may be a substrate for bacterial flora of the colon and serves as prebiotic. Short chain fatty acids (SCFA) produced by colonic fermentation of resistant starch may have impact on colonic function and health of humans. This paper summarises current knowledge on properties and health impact ...

  19. Development and utilization of cassava residue as feed resource%木薯渣作为饲料资源的开发与利用

    Institute of Scientific and Technical Information of China (English)

    黄萍; 齐仁立

    2012-01-01

    木薯渣是木薯加工过程中产生的下脚料,富含大量盼纤维和淀粉。近年来,木薯渣作为饲料资源进行开发和利用能够使其变废为宝。减少对环境的破坏,受到了国内外的普遍重视。其中微生物发酵处理能够使木薯渣的粗纤维降解,改善适口性,提高饲料转化率。本文就木薯渣的营养特点、加工处理和在畜禽养殖中的应用等作一概括和总结。%Cassava residue is the remainder of cassava starch. In recent years, cassava residue has been applied as utilization can increase the economic value of cassava residue The microbial fermentation is an ideal process to degradate processing, which the feed resource has rich fiber and for development. Its and reduce the damage to environment. the crude fiber in cassava residue and improve palatability as well as the feed conversion rate. This paper summarized the nutrition characteristic, the processing and the application in livestock and poultry of cassava residue

  20. Properties of fish protein hydrolysates: comparison of commercial and laboratorymade hydrolysates

    OpenAIRE

    Johansen, Arne Magne

    2009-01-01

    The aim of this work was to examine how addition of fish protein hydrolysates (FPH) influences the functional and antioxidative properties of fish calces.Hydrolysates from cod backbone were prepared in the laboratory and compared to hydrolysates from commercial producers in Denmark, USA and New Zealand. Two batches of hydrolysates were prepared enzymatically by mincing the backbones and digesting them with the endo-protease Protamex for either 20 or 50 minutes at 50°C. A moderate increase in ...

  1. Bemisia tabaci (Homoptera: Aleyrodidae) and Indian cassava mosaic virus transmission

    Science.gov (United States)

    Bemisia tabaci (Gennadius) adults from colonies reared on cassava or sweet potato plants were studied to determine their ability to transmit Indian cassava mosaic virus (ICMV) (Geminiviridae: Begomovirus) from cassava to cassava. Virus acquisition access (feeding) periods (AAP) of 48 h on ICMV-infec...

  2. Hydrolysis of Raw Corn Starch Granules by Glucoamylase and Product Inhibition During the Hydrolysis

    Institute of Scientific and Technical Information of China (English)

    WANG Jinpeng; ZENG Aiwu; LIU Zhen; YUAN Xigang; WU Shaomin

    2005-01-01

    Raw corn starch granules were hydrolysized by glucoamylase in a chemostat. The hydro-lysis of three different-sized granules shows that smaller granules undergo more hydrolyzation than larger ones. After 78 h, 97% of the granules was hydrolysized with diameter between 0.15 mm and 0.3 mm at 50 ℃. When corn starch concentration increased from 100 g/L to 250 g/L, the amount of reducing sugar produced was proportional to the initial substrate concentration and no substrate inhibition phenomenon appeared. In order to study the product inhibition exactly, the product from hydrolysis reaction itself was added into the hydrolysis system at the beginning of starch hydrolysis. Product inhibition with different quantities of product added were studied in the initial several hours, during which period enzyme inactivation could be neglected and product inhibition could be studied separately. The experiments indicate that product inhibition happens when the additional quantity exceeds 9.56 g/L.

  3. Strategies for developing the cassava industry

    International Nuclear Information System (INIS)

    The centralization of the cassava industry in tropical (and especially African) countries should be considered as a very important part of general strategy directed to the provision of the population with nutritionally balanced cassava foods. The Irish model of the development of dairy industry during the last 45 years had been a classical example of small involved groups in dairy farming getting together to pool their resources and family requirements to make a common objective succeed. This model based on a co-operative concept could be recommended for the cassava producing areas in order to improve this industry. The identification of the research areas required to improve the quality of the cassava fermented food products is another important part of the cassava strategy. These areas should include (i) fundamental studies of the various bacterial groups involved in the fermentation process and identification of the key groups involved at the various stages of fermentation (ii) strain screening programmes of these identified bacteria to select those which are most important to the fermentation of cassava (iii) studies to determine the appropriate methods for the propagation and the storage of these strains and (iv) systems to distribute these strains to the industries/small farmers/local co-operatives in cassava processing. Other technological and research aspects of improvement of the traditional fermentation practice of cassava are discussed in the paper. (author)

  4. Impact of structural characteristics on starch digestibility of cooked rice.

    Science.gov (United States)

    Tamura, Masatsugu; Singh, Jaspreet; Kaur, Lovedeep; Ogawa, Yukiharu

    2016-01-15

    To examine the impact of structural characteristics of cooked rice grains on their starch digestibility, a simulated in vitro gastro-small intestinal digestion technique was applied to intact and homogenised cooked rice samples. The starch hydrolysis percentage increased during simulated small intestinal digestion, in which approximately 65% and 24% of the starch was hydrolysed within the first 5min, for homogenised and intact cooked rice, respectively. The kinetic constant of homogenised cooked rice, which was regarded as an estimated digestion rate, was ∼8 times higher than the intact cooked rice. The homogenised and intact samples were also examined for any microstructural changes occurring during the in vitro digestion process using fluorescent and scanning electron microscopy. In the intact samples, the aleurone layers of the endosperm remained as thin-film like layers during in vitro digestion and thus may be regarded as less digestible materials that influence cooked rice digestibility.

  5. Impact of structural characteristics on starch digestibility of cooked rice.

    Science.gov (United States)

    Tamura, Masatsugu; Singh, Jaspreet; Kaur, Lovedeep; Ogawa, Yukiharu

    2016-01-15

    To examine the impact of structural characteristics of cooked rice grains on their starch digestibility, a simulated in vitro gastro-small intestinal digestion technique was applied to intact and homogenised cooked rice samples. The starch hydrolysis percentage increased during simulated small intestinal digestion, in which approximately 65% and 24% of the starch was hydrolysed within the first 5min, for homogenised and intact cooked rice, respectively. The kinetic constant of homogenised cooked rice, which was regarded as an estimated digestion rate, was ∼8 times higher than the intact cooked rice. The homogenised and intact samples were also examined for any microstructural changes occurring during the in vitro digestion process using fluorescent and scanning electron microscopy. In the intact samples, the aleurone layers of the endosperm remained as thin-film like layers during in vitro digestion and thus may be regarded as less digestible materials that influence cooked rice digestibility. PMID:26258706

  6. Fermented cassava waste and its utilization in broiler chickens rations

    OpenAIRE

    Supriyati,

    2003-01-01

    Cassava waste is a by-product of cassava flour industry and its amount is increasing following the increasing of cassava flour industry. Its utilization as a feedstuff, is limited by its low protein content. The cassava waste is only utilized as the energy source. One of the alternative technology in improving the utilization of cassava waste as a feedstuff, by improving the nutritive value through fermentation process. Fermentation was carried out by solid substrate fermentation using Asperg...

  7. Cassava diet--a cause for mucopolysaccharidosis?

    Science.gov (United States)

    Sreeja, V G; Leelamma, S

    2002-01-01

    Studies were carried out to determine the changes in glycosaminnoglycan (GAG) metabolism in rats fed cassava with varying cyanoglucoside levels and two levels of protein. Results indicated that there was an enhancement in the level of total and individual GAG with a corresponding reduction in the activity of enzymes involved in the degradation of glycosaminoglycan. These changes were significant for rats given a cassava diet (raw and boiled cassava) and low protein. The changes in total and individual GAG and the decrease in the activity of degrading enzymes was more for high cyanide (raw cassava) groups compared with other groups showing that consumption of untreated cassava is an additive factor for the promotion of mucopolysaccharidosis. PMID:12049146

  8. Characterization of chestnut (Castanea sativa, mill starch for industrial utilization

    Directory of Open Access Journals (Sweden)

    Ivo Mottin Demiate

    2001-03-01

    Full Text Available Studies were conducted to characterize the chestnut and its starch. Chemical composition of the chestnuts showed high level of starch. Moisture level in the raw nuts was around 50g/100g in wet basis and starch content, around 80g/100g in dry basis; other nut flour components were protein (5.58 g/100g, lipid (5.39 g/100g, crude fiber (2.34 g/100g and ash (2.14 g/100g. Starch fraction was chemically characterized in order to identify the granule quality as compared with those of cassava and corn. This fraction showed more lipids and proteins than the other starches. Chestnut starch granules showed peculiar shape, smaller than the control starches and low amount of damaged units. Chemical composition concerning amylose : amylopectin ratio was intermediate to that presented by cassava and corn starch granules. Water absorption at different temperatures as well as solubility were also intermediate but closer to that presented by cassava granules. The same behavior was observed in the interaction with dimethyl-sulfoxide. Native starch granules and those submitted to enzymatic treatment with commercial alpha-amylase and also with enzymes from germinated wheat were observed by scanning electronic microscopy. Water suspensions of chestnut starch granules were heated to form pastes that were studied comparatively to those obtained with cassava and corn starches. Viscographic pattern of chestnut starch pastes showed a characteristic profile with high initial viscosity but peak absence, high resistance to mechanical stirring under hot conditions and high final viscosity. There was no way to compare it with the paste viscographic profiles obtained with the control starches. Chestnut starch pastes were stable down to pH 4 but unstable at pH 3. The water losses observed in the chestnut starch pastes after freeze-thaw cycles showed more similarity to the pattern observed in corn starch pastes as well as clarity and strength of the gel. In general the results

  9. Safety of protein hydrolysates, fractions thereof and

    NARCIS (Netherlands)

    Schaafsma, Gertjan

    2009-01-01

    This paper evaluates the safety for humans with regard to consumption of protein hydrolysates and fractions thereof, including bioactive peptides. The available literature on the safety of protein, protein hydrolysates, fractions thereof and free amino acids on relevant food legislation is reviewed

  10. Quality evaluation of stiff porridges prepared from Irish potato (Solanum tuberosum) and pigeon pea (Cajanus cajan) starch blends.

    Science.gov (United States)

    Abu, Joseph Oneh; Enyinnaya, Chinma Chiemela; James, Samaila; Okeleke, Ezinne

    2012-06-01

    Quality attributes of stiff porridges prepared from Irish potato and pigeon pea starch blends were studied. Starches were extracted from Irish potato and pigeon pea using a wet extraction method. Various ratios of the starches were mixed and analyzed for chemical, functional and pasting properties. The starch blends were then prepared into stiff porridges for sensory evaluation using a 20-man sensory panel. Substitution of Irish potato starch with pigeon pea starch led to increases in protein (0.15 to 1.2%), fat (0.26 to 0.56%) and ash (0.30 to 0.69%) while the amylose content of the starch blends decreased (from 23.8 to 18.4%) respectively. Functional properties such as bulk density (0.75 to 0.60 g/cm(3)), water absorption capacity (3.1 to 2.6 g water/ g sample) and dispersibility (58.6 to 42.7%) decreased significantly (P < 0.05) at the highest concentration (50%) of pigeon pea starch respectively. Pasting properties such as peak, breakdown, final and setback viscosities increased with increasing levels of pigeon pea starch while peak time and pasting temperature decreased. The sensory attributes of stiff porridges were not adversely affected by pigeon pea starch inclusion. Therefore it should be possible to incorporate up to 50% of low digestible pigeon pea starch into Irish potato starch from legumes such as pigeon pea as alternatives to cassava starch in the preparation of stiff porridges. Such porridges made from Irish potato and legume starches could provide additional incentive for individuals requiring decreased and or slow starch digestibility such as diabetics. PMID:23729855

  11. Methods for assessing quality characteristics of non-grain starch staples. (Part 4. Advanced methods.)

    OpenAIRE

    Bainbridge, Z.; Tomlins, K.; Wellings, K; Westby, A.

    1996-01-01

    This manual sets out in a four-part publication the main methods necessary to evaluate the quality characteristics of nongrain starch staple (NGSS) food crops (cassava, sweet potato, banana, plantain, yam and cocoyam) and their processed products. It is designed to be a reference source and laboratory guide for food analysis laboratories and those concerned with the quality of NGSS. It is hoped that the provision of this manual and its active promotion through workshops will assist in the upt...

  12. Methods for assessing quality characteristics of non-grain starch staples. (Part 3. Laboratory methods.)

    OpenAIRE

    Bainbridge, Z.; Tomlins, K.; Wellings, K; Westby, A.

    1996-01-01

    This manual sets out in a four-part publication the main methods necessary to evaluate the quality characteristics of nongrain starch staple (NGSS) food crops (cassava, sweet potato, banana, plantain, yam and cocoyam) and their processed products. It is designed to be a reference source and laboratory guide for food analysis laboratories and those concerned with the quality of NGSS. It is hoped that the provision of this manual and its active promotion through workshops will assist in the upt...

  13. Methods for assessing quality characteristics of non-grain starch staples. (Part 1. Introduction.)

    OpenAIRE

    Bainbridge, Z.; Tomlins, K.; Wellings, K; Westby, A.

    1996-01-01

    This manual sets out in a four-part publication the main methods necessary to evaluate the quality characteristics of nongrain starch staple (NGSS) food crops (cassava, sweet potato, banana, plantain, yam and cocoyam) and their processed products. It is designed to be a reference source and laboratory guide for food analysis laboratories and those concerned with the quality of NGSS. It is hoped that the provision of this manual and its active promotion through workshops will assist in the upt...

  14. Methods for assessing quality characteristics of non-grain starch staples. (Part 2. Field Methods.)

    OpenAIRE

    Bainbridge, Z.; Tomlins, K.; Wellings, K; Westby, A.

    1996-01-01

    This manual sets out in a four-part publication the main methods necessary to evaluate the quality characteristics of nongrain starch staple (NGSS) food crops (cassava, sweet potato, banana, plantain, yam and cocoyam) and their processed products. It is designed to be a reference source and laboratory guide for food analysis laboratories and those concerned with the quality of NGSS. It is hoped that the provision of this manual and its active promotion through workshops will assist in the upt...

  15. Pasting, textural and thermal properties of resistant starch prepared from potato (Solanum tuberosum) starch using pullulanase enzyme.

    Science.gov (United States)

    Reddy, Chagam Koteswara; Pramila, S; Haripriya, Sundaramoorthy

    2015-03-01

    Pullulanase enzyme (40 U/g, 10 h) was used for enzymatic hydrolysis of potato starch which was autoclaved (121 °C/30 min), stored under refrigeration (4 °C/24 h) and lyophilized. Comparison of morphological, pasting, textural and thermal properties among native hydrolysed starch (V2) and gelatinized hydrolysed starch (V3) prepared using pullulanase enzyme on potato starch (V1) were studied. The round, elliptical, irregular and oval shape with smooth surface of V1 was replaced with amorphous mass of cohesive structure leading to loss of granular appearance in V2 and V3. The percentage of amylose and resistant starch content of V2 (27.16 %) and (24.16 %); V3 (51.44 %) and (29.35 %) was higher when compared to V1 (22.17 %) and (3.62 %). The swelling power of V1 observed at 60 °C (0.85 %) and 95 °C (8.64 %) were significantly different from V2 at 60 °C (4.97 %) and 95 °C (7.66 %) and that of V3 at 60 °C (5.82 %) and 95 °C (7.5 %). Significance difference in water solubility (7.62 %) and absorption capacity (6.11 %) was noted in V3 when compared with V1 and V2 owing to amylose/amylopectin content. Increase in water solubility and absorption capacity along with decrease in swelling power of V2 and V3 was noted due to hydrolytic and thermal process. RS obtained from hydrolysis showed a reduction in viscosity, indicating the rupture of starch molecules. The viscosity was found to be inversely proportional to the RS content in the sample. The thermal properties of RS increased due to the retrogradation and recrystallization (P < 0.05). PMID:25745229

  16. Characterization of an 18,166 EST dataset for cassava (Manihot esculenta Crantz) enriched for drought-responsive genes.

    Science.gov (United States)

    Lokko, Y; Anderson, J V; Rudd, S; Raji, A; Horvath, D; Mikel, M A; Kim, R; Liu, L; Hernandez, A; Dixon, A G O; Ingelbrecht, I L

    2007-09-01

    Cassava (Manihot esculenta Crantz) is a staple food for over 600 million people in the tropics and subtropics and is increasingly used as an industrial crop for starch production. Cassava has a high growth rate under optimal conditions but also performs well in drought-prone areas and on marginal soils. To increase the tools for understanding and manipulating drought tolerance in cassava, we generated expressed sequence tags (ESTs) from normalized cDNA libraries prepared from dehydration-stressed and control well-watered tissues. Analysis of a total of 18,166 ESTs resulted in the identification of 8,577 unique gene clusters (5,383 singletons and 3,194 clusters). Functional categories could be assigned to 63% of the unigenes, while another approximately 11% were homologous to hypothetical genes with unclear functions. The remaining approximately 26% were not significantly homologous to sequences in public databases suggesting that some may be novel and putatively specific to cassava. The dehydration-stressed library uncovered numerous ESTs with recognized roles in drought-responses, including those that encode late-embryogenesis-abundant proteins thought to confer osmoprotective functions during water stress, transcription factors, heat-shock proteins as well as proteins involved in signal transduction and oxidative stress. The unigene clusters were screened for short tandem repeats for further development as microsatellite markers. A total of 592 clusters contained 646 repeats, representing 3.3% of the ESTs queried. The ESTs presented here are the first dehydration stress transcriptome of cassava and can be utilized for the development of microarrays and gene-derived molecular markers to further dissect the molecular basis of drought tolerance in cassava.

  17. Characteristics of raw starch degrading alpha-amylase from Bacillus aquimaris MKSC 6.2 associated with soft coral Sinularia sp.

    NARCIS (Netherlands)

    Puspasari, Fernita; Nurachman, Zeily; Noer, Achmad Saefuddin; Radjasa, Ocky Karna; van der Maarel, Marc J. E. C.; Natalia, Dessy

    2011-01-01

    Partially purified alpha-amylase from Bacillus aquimaris MKSC 6.2, a bacterium isolated from a soft coral Sinularia sp., Merak Kecil Island, West Java, Indonesia, showed an ability to degrade raw corn, rice, sago, cassava, and potato starches with adsorption percentage in the range of 65-93%. Corn h

  18. Starch metabolism in leaves.

    Science.gov (United States)

    Orzechowski, Sławomir

    2008-01-01

    Starch is the most abundant storage carbohydrate produced in plants. The initiation of transitory starch synthesis and degradation in plastids depends mainly on diurnal cycle, post-translational regulation of enzyme activity and starch phosphorylation. For the proper structure of starch granule the activities of all starch synthase isoenzymes, branching enzymes and debranching enzymes are needed. The intensity of starch biosynthesis depends mainly on the activity of AGPase (adenosine 5'-diphosphate glucose pyrophosphorylase). The key enzymes in starch degradation are beta-amylase, isoamylase 3 and disproportionating enzyme. However, it should be underlined that there are some crucial differences in starch metabolism between heterotrophic and autotrophic tissues, e.g. is the ability to build multiprotein complexes responsible for biosynthesis and degradation of starch granules in chloroplasts. The observed huge progress in understanding of starch metabolism was possible mainly due to analyses of the complete Arabidopsis and rice genomes and of numerous mutants with altered starch metabolism in leaves. The aim of this paper is to review current knowledge on transient starch metabolism in higher plants. PMID:18787712

  19. Starch-lignin foams

    Directory of Open Access Journals (Sweden)

    2010-05-01

    Full Text Available Although starch foams are well known as biodegradable alternatives to foamed polystyrene, starch-lignin foams have not previously been reported. Lignin is an abundant byproduct of paper manufacture usually burned as fuel for lack of higher-value uses. We have prepared novel starch-kraft lignin foams with a known technique similar to compression molding. Replacing 20% of the starch with lignin has no deleterious effect on density or morphology as indicated by scanning electron microscopy: a thin outer layer of approximately 100 µm encloses a region of cellular structure containing 100–200 µm voids, with the major internal region of the foam consisting of large voids of up to 1 mm in size. Powder X-ray diffraction shows residual structure in both starch and starch-lignin foams. Differential scanning calorimetry displays endothermic transitions in the starch foam but not in the starch-lignin foam, indicating that lignin stabilizes the residual starch structure. Lignin decreases water absorption; diffusion constants for the starch and starch-lignin foams are 2.68•10–6 and 0.80•10–6 cm2/sec, respectively. The flexural strength of the starch-lignin foam is similar to that of foamed polystyrene, the strain at maximum stress is smaller, and the modulus of elasticity is larger.

  20. 木薯渣发酵饲料的工艺筛选%Screening of technology in cassava slag fermentation feed

    Institute of Scientific and Technical Information of China (English)

    艾必燕; 刘长忠; 陈建康; 杨扬; 米本中; 黄倩妮; 樵星芳

    2012-01-01

    Using cassava slag as the main raw material, with aspergillus, trichoderma viride and rhizopus R2 for fermentation strains, the test is to optimize cassava slag fermentation technology producing tropina feed. The appropriate conditions of cassava slag fermentation are that adding amount of liquid spawn is 3%, adding amount of nitrogen source is 10%, fermentation temperature is 37 ℃, fermentation time is 4 days. Cassava slag is a mixture, its highest level of non-nitrogen compounds is 78.7%, main component is soluble starch compounds (such as monosaccharide and starch), but its crude protein content is very low, amino acid composition is extremely uneven, it has poor effect to feed cassava slag directly, so most of the cassava slag cannot be used, which not only causes the waste of resources, but also seriously pollutes environment. Processing cassava slag into feed materials can make full use of the waste in starch industry, it is favorable to the environment protection, and it also can significantly reduce the cost of feed, improve the utilization value and economic benefits of cassava slag.%以木薯生产中产生的废渣为主要原料,以黑曲霉、绿色木霉和根霉R2为发酵菌种,优化木薯渣发酵生产菌体蛋白饲料的工艺.初步确定了木薯渣发酵的适宜条件,即液体菌种添加量为3%,氮源添加量为20%,发酵温度37℃,发酵时间为4d,经试验验证,此发酵条件下发酵饲料中粗蛋白含量较高,可达到蛋白饲料对蛋白质含量的要求.通过处理木薯渣变为动物的饲料原料,不仅可充分利用淀粉工业的废弃物,有利于环境保护,而且可显著降低饲养成本,从而提高了木薯渣的利用价值和经济效益.

  1. Cassava; African perspective on space agriculture

    Science.gov (United States)

    Katayama, Naomi; Njemanze, Philip; Nweke, Felix; Space Agriculture Task Force, J.; Katayama, Naomi; Yamashita, Masamichi

    Looking on African perspective in space agriculture may contribute to increase diversity, and enforce robustness for advanced life support capability. Cassava, Manihot esculentaand, is one of major crop in Africa, and could be a candidate of space food materials. Since resource is limited for space agriculture in many aspects, crop yield should be high in efficiency, and robust as well. The efficiency is measured by farming space and time. Harvest yield of cassava is about 41 MJ/ m2 (70 ton/ha) after 11 months of farming. Among rice, wheat, potato, and sweet potato, cassava is ranked to the first place (40 m2 ) in terms of farming area required to supply energy of 5 MJ/day, which is recommended for one person. Production of cassava could be made under poor condition, such as acidic soil, shortage of fertilizer, draught. Laterite, similar to Martian regolith. Propagation made by stem cutting is an advantage of cassava in space agriculture avoiding entomophilous or anemophilous process to pollinate. Feature of crop storage capability is additional factor that determines the efficiency in the whole process of agriculture. Cassava root tuber can be left in soil until its consumption. Cassava might be an African contribution to space agriculture.

  2. Surface properties of water soluble surfactants, starch and their complexes by various methods

    International Nuclear Information System (INIS)

    Surface, interfacial tensions and reduced viscosities were measured for water soluble surfactant and starch solutions in order to determine their potential as stabilisers, emulsifiers or cleansers. The surface tension and reduced viscosity for an acid hydrolysed starch (potato) initially were declined with concentration and then reached an equilibrium value of 56 mN/m and 3.1 dm 3/mol, at 20-40 wt.%. Surface, interfacial tensions and reduced viscosity of starch with surfactant mixture using the ratio 40/60 decreased more rapidly with concentration reaching values of 41-44 mN/m, and 2.5 dm/sup 3//mol, respectively, at 40 wt.%. There was little dependence of surface or interfacial tensions on degree of substitution between 0.3-0.8 and amylose content of starch. Surface and interfacial tensions for starch /surfactants mixtures were lower than those for only starch, particularly at lower concentrations. Emulsions of soybean oil/water mixtures were successfully stabilised for >1 day by potato starch acetate/octenylsuccinate and acetate/ dodecenylsuccinate but not by starch and surfactants. Therefore, these starches may represent biodegradable, economically alternatives to some emulsifiers, soap or detergents filler with effective cleansing activity and coating polymers currently in use. (author)

  3. CHEMICAL COMPOSITIONS AND RESISTANT STARCH CONTENT IN STARCHY FOODS

    Directory of Open Access Journals (Sweden)

    Anuchita Moongngarm

    2013-01-01

    Full Text Available Resistant Starch (RS is one of nature’s most interesting bioactive compounds. There is a wide variety of starchy food plants in Thailand that are good sources of RS, but they have not been well studied. As such, this study was carried out to investigate the potential food source of RS. Twenty-two promising food plants were selected. The samples included (1 cereals comprised of five long grain rice of O. sativa L. and sweet corn, (2 six species of root and tuber crops, (3 green banana fruits (Musa sapientum L. composed of ABB group, AAB group and AAA group at the first stage of ripening and (4 legume seeds included cowpea seeds (3 different cultivars, red bean, red kidney bean and mung bean. All food plants were determined for chemical compositions, resistant starch, non-resistant starch, total starch and amylose content. The study found that the starchy foods varied in their chemical compositions. The major composition of all foods was carbohydrate ranging between 58.19 (in black speck cow pea and 87.21% (in cassava root, whilst the fat, ash and fiber were observed only in small quantities. The protein content was highest in legume seeds (20.78 to 27.22%. For the study on starch compositions, green bananas contained highest amount of resistant starch ranging between 35.14 and 45.87%, indicating that more than a half of total starch in banana RS content varying from 35.14 to 45.87%, whereas the RS content of legumes ranging from 2.33 to 10.63% and 1.16 to 4.85% in cereal grains. Most of the starchy food plants contained moderate to high level of amylose (11.45-34.85%, except the waxy rice (2.72%.

  4. Proteomics of barley starch granules

    OpenAIRE

    Borén, Mats

    2005-01-01

    Starches in various forms are an important part of the human diet. Furthermore, the use of starch as a renewable and biodegradable raw material for various industrial applications is becoming increasingly attractive. Non-food applications of starch make new demands on quality and type of starches produced. Ideally these new demands should be met by tailoring starches within the plant. A number of such in planta produced specialty starches exist today, e.g. high-amylose starch. Our aims with t...

  5. Production of L-lactic acid from Cassava peel wastes using single and mixed cultures of Rhizopus oligosporus and Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Nwokoro Ogbonnaya

    2014-01-01

    Full Text Available Production of L-lactic acid using cultures of Rhizopus oligosporus and Lactobacillus plantarum was investigated. Cassava peels were hydrolyzed by boiling for 1 h in either NaOH or HCl solutions followed by neutralization to a pH of 6.2. Reducing sugar produced from the hydrolysates increased with increasing concentrations of alkali or acid. Samples hydrolyzed with HCl produced a maximum reducing sugar concentration of 402 mg/g substrate while alkali hydrolyzed samples produced a maximum reducing sugar concentration of 213 mg/g substrate. Hydrolysates were amended with 0.5% ammonium sulphate solution and inoculated with either single or mixed cultures of Rhizopus oligosporus and Lactobacillus plantarum and incubated for 48 h for lactic acid production. The best lactic acid production of 50.2 g/100g substrate was observed in a mixed culture fermentation of acid hydrolyzed peels. Mixed culture fermentation of alkali hydrolyzed peels produced a maximum lactic acid concentration of 36.4 g/100g substrate. Un hydrolyzed cassava peels inoculated with a mixed culture of the microorganisms produced only 4.6 g/100g substrate. This work reports an efficient use of cassava peels for bio-product formation through microbial fermentation.

  6. Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents

    Directory of Open Access Journals (Sweden)

    Raheleh Ghanbari

    2012-12-01

    Full Text Available Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp. were evaluated. Papain hydrolysis showed the highest DH value (89.44%, followed by alcalase hydrolysis (83.35%. Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions.

  7. Starch Bioengineering in Barley

    DEFF Research Database (Denmark)

    Shaik, Shahnoor Sultana

    by the amylolytic enzymes while the amylose-only endosperm starch exhibits high resistance to degradation and hence less available for degradation. With the aim to investigate the hypothesis, starch molecular structures were modulated with the above mentioned modifications and were studied for the effects....... This was achieved by endosperm-specific overexpression of Solanum tuberosum GWD to generate hyper-phosphorylated (HP) starch and endosperm-specific RNAi suppression of all three starch branching enzyme (SBE) isoforms to generate amylose-only (AO) starch in barley (cv. Golden Promise). In first and second study......Starch represents the most important carbohydrate used for food and feed purposes. Increasingly, it is also used as a renewable raw material, as a source of biofuel, and for many different industrial applications. Progress in understanding starch biosynthesis, and investigations of the genes...

  8. Cassava based diets for sustainable ruminant production

    International Nuclear Information System (INIS)

    Cassava (Manihot esculenta, Crantz) is an annual crop grown widely in the tropical regions of Africa, Asia and Latin America. It thrives in sandy-loam soils with low organic matter and in climate with low rainfall and high temperature. Cassava could also response more with manure fertilization. Cassava tubers contain high levels of energy and minimal levels of crude protein, have been used as readily fermentable energy in ruminant rations, and have been used extensively as a feed for livestock. Recent attempts have been made to develop new products using cassava chips as an energy source with urea as non-protein nitrogen (NPN). Two new cassava based products have been developed: cassarea and cassaya. Cassarea was formulated to contain the following ingredients: 57.1% Cassava chips + 9.9% urea and 3% tallow (Cassarea I, 30% CP); 83.6% Cassava chips + 13.4% urea and 3% tallow (Cassarea II, 40% CP); 80.2% Cassava chips + 16.8% urea and 3% tallow (Cassarea III, 50% CP). Cassarea was tested for rumen degradability using the nylon bag technique and was found to have a 46.2 to 56.7% effective DM degradability. Further investigations with Cassarea II (40% CP) showed that it could be used to replace SBM in the rations of lactating cows, but supplementation with a rumen by-pass protein such as cottonseed meal would be recommended. Cassaya (30% CP) is a product formulated using chopped whole cassava crop hay (85%) + soybean meal (5%) + cassava chips (5%) + urea (2%) + tallow (2%) + sulphur (1%), mixing with water, pressed through a pelleting machine and sun-dried to at least 85% DM. The use of Cassaya in lactating dairy cows as a protein source proved to be efficient in promoting rumen fermentation, improved milk yield and composition and providing an increased economical return. Moreover, cassava hay (CH) has been applied in ruminant nutrition as a high-quality protein supplement for dairy cattle, beef and buffalo production. CH consists of whole crop of cassava harvested at

  9. Hydrolysis of wheat B-starch and characterisation of acetylated maltodextrin.

    Science.gov (United States)

    Smrčková, Petra; Horský, Jiří; Šárka, Evžen; Koláček, Jaroslav; Netopilík, Miloš; Walterová, Zuzana; Kruliš, Zdeněk; Synytsya, Andrey; Hrušková, Kateřina

    2013-10-15

    Wheat B-starch was hydrolysed by α-amylase "Liquozyme supra" from Bacillus licheniformis at 90 °C and pH 7. After 2 h, the dextrose equivalent was 18; according to size exclusion chromatography, however, the hydrolysate contained not only dominant malto-oligosaccharides with the degree of polymerisation (DP)40. This non-uniformity of acetylated maltodextrin, both with respect to DP and to DS, must be taken into account in the development of acetylated-maltodextrin applications such as use as plasticisers or compatibilisers in biodegradable composites.

  10. Thermoplastic starch materials prepared from rice starch

    International Nuclear Information System (INIS)

    Rice starch is a source still little studied for the preparation of thermoplastic materials. However, its characteristics, such as the presence of proteins, fats and fibers may turn into thermoplastics with a better performance. The present study intends the evaluation of the viability of making starch thermoplastic from rice starch and glycerol as plasticizer. The results of X-ray diffraction and scanning electronic microscopy demonstrate the thermoplastic acquisition. The increase of plasticizer content brings on more hydrophilic thermoplastics with less resistance to tension and elongation at break. (author)

  11. Poliuretanos elastoméricos obtenidos a partir de aceite de ricino y almidón de yuca original y modificado con anhídrido propiónico: síntesis, propiedades fisicoquímicas y fisicomecánicas Polyurethane elastomers from castor oil and chemically modified yucca starch: synthesis and physical-chemical, physical-mechanical and thermical properties

    OpenAIRE

    Manuel F. Valero; Jorge E. Pulido; Álvaro Ramírez; Luz E. Higuita; Sandra M. Arias; Carlos S. Gonzáles; Leonidas J. Ruiz

    2010-01-01

    Chemical modification of cassava starch was conducted through an acylation reaction by using pyridine and propionic anhydride to replace the functional groups of starch. Polyurethane elastomers were prepared using suspensions of the mixture obtained from castor oil and yucca starch that was modified by a propionic anhydride reaction. The suspensions were characterized by means of tests based on The Fourier Transform Infrared Spectroscopy and the Hydroxyl Index. The castor oil-AMP suspensions ...

  12. Production of methane by co-digestion of cassava pulp with various concentrations of pig manure

    Energy Technology Data Exchange (ETDEWEB)

    Panichnumsin, Pornpan [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, Thungkru, Bangkok 10140 (Thailand); Excellent Center of Waste Utilization and Management, National Center for Genetic Engineering and Biotechnology, Bangkhuntien, Bangkok 10150 (Thailand); Nopharatana, Annop [Pilot Plant Development and Training Institute, King Mongkut' s University of Technology Thonburi, Bangkhuntien, Bangkok 10150 (Thailand); Ahring, Birgitte [AAU, Copenhagen Institute of Technology, Lautrupvang 15, 2750 Ballerup (Denmark); Chaiprasert, Pawinee [School of Bioresources and Technology, King Mongkut' s University of Technology Thonburi, Bangkhuntien, Bangkok 10150 (Thailand)

    2010-08-15

    Cassava pulp is a major by-product produced in a cassava starch factory, containing 50-60% of starch (dry basis). Therefore, in this study we are considering its potential as a raw material substrate for the production of methane. To ensure sufficient amounts of nutrients for the anaerobic digestion process, the potential of co-digestion of cassava pulp (CP) with pig manure (PM) was further examined. The effect of the co-substrate mixture ratio was carried out in a semi-continuously fed stirred tank reactor (CSTR) operated under mesophilic condition (37 C) and at a constant OLR of 3.5 kg VS m{sup -3} d{sup -1} and a HRT of 15 days. The results showed that co-digestion resulted in higher methane production and reduction of volatile solids (VS) but lower buffering capacity. Compared to the digestion of PM alone, the specific methane yield increased 41% higher when co-digested with CP in concentrations up to 60% of the incoming VS. This was probably due to an increase in available easily degradable carbohydrates as the CP ratio in feedstock increased. The highest methane yield and VS removal of 306 mL g{sup -1} VS{sub added} and 61%, respectively, were achieved with good process stability (VFA:Alkalinity ratio < 0.1) when CP accounted for 60% of the feedstock VS. A further increase of CP of the feedstock led to a decrease in methane yield and solid reductions. This appeared to be caused by an extremely high C:N ratio of the feedstock resulting in a deficiency of ammonium nitrogen for microbial growth and buffering capacity. (author)

  13. Production of methane by co-digestion of cassava pulp with various concentrations of pig manure

    International Nuclear Information System (INIS)

    Cassava pulp is a major by-product produced in a cassava starch factory, containing 50-60% of starch (dry basis). Therefore, in this study we are considering its potential as a raw material substrate for the production of methane. To ensure sufficient amounts of nutrients for the anaerobic digestion process, the potential of co-digestion of cassava pulp (CP) with pig manure (PM) was further examined. The effect of the co-substrate mixture ratio was carried out in a semi-continuously fed stirred tank reactor (CSTR) operated under mesophilic condition (37 oC) and at a constant OLR of 3.5 kg VS m-3 d-1 and a HRT of 15 days. The results showed that co-digestion resulted in higher methane production and reduction of volatile solids (VS) but lower buffering capacity. Compared to the digestion of PM alone, the specific methane yield increased 41% higher when co-digested with CP in concentrations up to 60% of the incoming VS. This was probably due to an increase in available easily degradable carbohydrates as the CP ratio in feedstock increased. The highest methane yield and VS removal of 306 mL g-1 VSadded and 61%, respectively, were achieved with good process stability (VFA:Alkalinity ratio < 0.1) when CP accounted for 60% of the feedstock VS. A further increase of CP of the feedstock led to a decrease in methane yield and solid reductions. This appeared to be caused by an extremely high C:N ratio of the feedstock resulting in a deficiency of ammonium nitrogen for microbial growth and buffering capacity.

  14. Hydrolysates of lignocellulosic materials for biohydrogen production.

    Science.gov (United States)

    Chen, Rong; Wang, Yong-Zhong; Liao, Qiang; Zhu, Xun; Xu, Teng-Fei

    2013-05-01

    Lignocellulosic materials are commonly used in bio-H2 production for the sustainable energy resource development as they are abundant, cheap, renewable and highly biodegradable. In the process of the bio-H2 production, the pretreated lignocellulosic materials are firstly converted to monosaccharides by enzymolysis and then to H2 by fermentation. Since the structures of lignocellulosic materials are rather complex, the hydrolysates vary with the used materials. Even using the same lignocellulosic materials, the hydrolysates also change with different pretreatment methods. It has been shown that the appropriate hydrolysate compositions can dramatically improve the biological activities and bio-H2 production performances. Over the past decades, hydrolysis with respect to different lignocellulosic materials and pretreatments has been widely investigated. Besides, effects of the hydrolysates on the biohydrogen yields have also been examined. In this review, recent studies on hydrolysis as well as their effects on the biohydrogen production performance are summarized. PMID:23710634

  15. Applications of Protein Hydrolysates in Biotechnology

    Science.gov (United States)

    Pasupuleti, Vijai K.; Holmes, Chris; Demain, Arnold L.

    By definition, protein hydrolysates are the products that are obtained after the hydrolysis of proteins and this can be achieved by enzymes, acid or alkali. This broad definition encompasses all the products of protein hydrolysis - peptides, amino acids and minerals present in the protein and acid/alkali used to adjust pH (Pasupuleti 2006). Protein hydrolysates contain variable side chains depending on the enzymes used. These side chains could be carboxyl, amino, imidazole, sulfhydryl, etc. and they may exert specific physiological roles in animal, microbial, insect and plant cells. This introductory chapter reviews the applications of protein hydrolysates in biotechnology. The word biotechnology is so broad and for the purpose of this book, we define it as a set of technologies such as cell culture technology, bioprocessing technology that includes fermentations, genetic engineering technology, microbiology, and so on. This chapter provides introduction and leads to other chapters on manufacturing and applications of protein hydrolysates in biotechnology.

  16. Biofunctional Properties of Enzymatic Squid Meat Hydrolysate

    Science.gov (United States)

    Choi, Joon Hyuk; Kim, Kyung-Tae; Kim, Sang Moo

    2015-01-01

    Squid is one of the most important commercial fishes in the world and is mainly utilized or consumed as sliced raw fish or as processed products. The biofunctional activities of enzymatic squid meat hydrolysate were determined to develop value-added products. Enzymatic squid hydrolysate manufactured by Alcalase effectively quenched 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, and hydrogen peroxide radical with IC50 values of 311, 3,410, and 111.5 μg/mL, respectively. Angiotensin I-converting enzyme inhibitory activity of squid hydrolysate was strong with an IC50 value of 145.1 μg/mL, while tyrosinase inhibitory activity with an IC50 value of 4.72 mg/mL was moderately low. Overall, squid meat hydrolysate can be used in food or cosmetic industries as a bioactive ingredient and possibly be used in the manufacture of seasoning, bread, noodle, or cosmetics. PMID:25866752

  17. Hydrolysates of lignocellulosic materials for biohydrogen production.

    Science.gov (United States)

    Chen, Rong; Wang, Yong-Zhong; Liao, Qiang; Zhu, Xun; Xu, Teng-Fei

    2013-05-01

    Lignocellulosic materials are commonly used in bio-H2 production for the sustainable energy resource development as they are abundant, cheap, renewable and highly biodegradable. In the process of the bio-H2 production, the pretreated lignocellulosic materials are firstly converted to monosaccharides by enzymolysis and then to H2 by fermentation. Since the structures of lignocellulosic materials are rather complex, the hydrolysates vary with the used materials. Even using the same lignocellulosic materials, the hydrolysates also change with different pretreatment methods. It has been shown that the appropriate hydrolysate compositions can dramatically improve the biological activities and bio-H2 production performances. Over the past decades, hydrolysis with respect to different lignocellulosic materials and pretreatments has been widely investigated. Besides, effects of the hydrolysates on the biohydrogen yields have also been examined. In this review, recent studies on hydrolysis as well as their effects on the biohydrogen production performance are summarized.

  18. WHEY PROTEIN HYDROLYSATES: TECHNO-FUNCTIONAL PERSPECTIVE

    OpenAIRE

    Sumaira H. Khan

    2013-01-01

    The paper deals with the techno-functional perspective of whey protein hydrolysates. Molecular changes occurring during protein hydrolysis result in modified techno-functional behavior of the hydrolysates compared to the intact protein such as altered solubility, viscosity, sensory properties, and emulsion and foam properties. It plays important role as an antioxidant to help increase body immune system. Whey components have ability to improve the host antioxidant defense and lower oxidant bu...

  19. RNAi-mediated resistance to Cassava brown streak Uganda virus in transgenic cassava.

    Science.gov (United States)

    Yadav, Jitender S; Ogwok, Emmanuel; Wagaba, Henry; Patil, Basavaprabhu L; Bagewadi, Basavaraj; Alicai, Titus; Gaitan-Solis, Eliana; Taylor, Nigel J; Fauquet, Claude M

    2011-09-01

    Cassava brown streak disease (CBSD), caused by Cassava brown streak Uganda virus (CBSUV) and Cassava brown streak virus (CBSV), is of new epidemic importance to cassava (Manihot esculenta Crantz) production in East Africa, and an emerging threat to the crop in Central and West Africa. This study demonstrates that at least one of these two ipomoviruses, CBSUV, can be efficiently controlled using RNA interference (RNAi) technology in cassava. An RNAi construct targeting the near full-length coat protein (FL-CP) of CBSUV was expressed constitutively as a hairpin construct in cassava. Transgenic cassava lines expressing small interfering RNAs (siRNAs) against this sequence showed 100% resistance to CBSUV across replicated graft inoculation experiments. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed the presence of CBSUV in leaves and some tuberous roots from challenged controls, but not in the same tissues from transgenic plants. This is the first demonstration of RNAi-mediated resistance to the ipomovirus CBSUV in cassava.

  20. The BioCassava Plus program: Biofortification of cassava for sub-Saharan Africa

    Science.gov (United States)

    More than 250 million Africans rely on the starchy root crop cassava (Manihot esculenta) as their staple source of calories. A typical cassava-based diet, however, provides less than 30% of the minimum daily requirement for protein and only 10-20% of that for iron, zinc, and vitamin A. The BioCassav...

  1. Characterization of starch extracted from the roots of Cissus simsiana Roem. & Schult

    Directory of Open Access Journals (Sweden)

    Diego Palmiro Ramirez Ascheri

    2014-02-01

    Full Text Available The aim of this study was to investigate the characterization of starch from Cissus simsiana Roem. & Schult. roots. The starch was extracted by steeping, wet grinding and sedimentation processes and its yield was calculated. Isolated starch was then characterized for chemical composition, morphology and granules size distribution, X-ray diffraction, mid-infrared spectra, swelling powder and solubility, pasting and thermal properties and clarity and syneresis behavior. The starch yield, based on starch presence in the root that can be isolated, were between 13.68% with 3.12 10-3 mg/g of carotenoids. C. simsiana granules were predominantly ellipsoids with 50-60 mm length and 20-30 mm wide. They exhibited B-type X-ray diffraction pattern with 41.2% of crystallinity, apparent amylose content of 26.2% and presented similar mid-infrared spectra to other starches. Onset and peak gelatinization temperatures were 64.2 and 68.56°C, respectively, and gelatinization enthalpy was 19.2 J/g. The apparent viscosity profile was comparable to cassava starch, but with higher peak viscosity (6500 cP, lower set back viscosity (600 cP and less clear gel showing syneresis.

  2. Production of Cyclodextrins by CGTase from Bacillus clausii Using Different Starches as Substrates

    Science.gov (United States)

    Alves-Prado, H. F.; Carneiro, A. A. J.; Pavezzi, F. C.; Gomes, E.; Boscolo, M.; Franco, C. M. L.; da Silva, R.

    Cyclodextrins (CDs) are cyclic oligasaccharides composed by d-glucose monomers joined by α-1,4-d glicosidic linkages. The main types of CDs are α-, β- and γ-CDs consisting of cycles of six, seven, and eight glucose monomers, respectively. Their ability to form inclusion complexes is the most important characteristic, allowing their wide industrial application. The physical property of the CD-complexed compound can be altered to improve stability, volatility, solubility, or bio-availability. The cyclomaltodextrin glucanotransferase (CGTase, EC 2.4.1.19) is an enzyme capable of converting starch into CD molecules. In this work, the CGTase produced by Bacillus clausii strain E16 was used to produce CD from maltodextrin and different starches (commercial soluble starch, corn, cassava, sweet potato, and waxy corn starches) as substrates. It was observed that the substrate sources influence the kind of CD obtained and that this CGTase displays a β-CGTase action, presenting a better conversion of soluble starch at 1.0%, of which 80% was converted in CDs. The ratio of total CD produced was 0:0.89:0.11 for α/β/γ. It was also observed that root and tuber starches were more accessible to CGTase action than seed starch under the studied conditions.

  3. Aroma interactions with starch

    DEFF Research Database (Denmark)

    Jørgensen, Anders Dysted

    -MS and solvent extractions. Addition of water to the extraction lowered the amount of aroma released, and addition of a starch-degrading enzyme, α-amylase, did not significantly change the amount extracted. Studies by differential scanning calorimetry and wide-angle X-ray scattering did not show complete...... carbohydrates. Stimulation with starch induced expression of starch-degrading enzymes, while stimulation with the hemicellulose xylan induced expression of xylanases. One particular hypothetical protein was ubiquitously expressed. This protein had no apparent homology with known proteins, but may iv be involved......Starches are used to enhance aroma perception in low-fat foods. Aroma compounds can bind physically to the starch in grooves on the surface or they can form complexes inside amylose helices. This study has been divided into two parts: one part regarding binding of aromas to starches and their aroma...

  4. THERMAL ANALYSIS, RHEOLOGY, X-RAY DIFFRACTOMETRY AND ATOMIC FORCE MICROSCOPY IN THE EVALUATION OF BINARY MIXTURES OF “STARCH-HYDROCOLLOIDS”

    Directory of Open Access Journals (Sweden)

    Crislaine Alberton

    2014-02-01

    Full Text Available Starch is arguably the most investigated biopolymer in the world and the cassava starch that is extracted from Manihot esculenta Crantz, represents an important vegetal crop in tropical countries, where its roots and derivatives serve as food and a source of energy. The main composition of these roots is 70-80% water, 16-24% starch and small quantities (<4% of protein, lipids vitamins and minerals. Hydrocolloids, or gums, are substances consisting of a hydrophilic long-chain with colloidal properties that, in water-based systems, produce gels. Starches and hydrocolloids are often used together in food systems to provide texture, water mobility, control moisture, improve product quality and stability, facilitate processing and reduce costs. In this study, the interactions between cassava and starch-hydrocolloids (1% of the following gums: CMC, jatahy, pectin and xanthan were investigated. The TG/DTG method made it possible to determine the thermal decomposition of each sample, which under air atmosphere occurs in three steps. Little difference was observed in the degree of relative crystallinity (XRD and in the average roughness or average diameter of the starch granules (NC-AFM. The viscosity and pasting properties (RVA increased, and were higher for starch treated with jatahy gum. A large decrease was observed in peak temperature and gelatinisation enthalpy for the treated samples (DSC.

  5. Large-scale SNP discovery through RNA sequencing and SNP genotyping by targeted enrichment sequencing in cassava (Manihot esculenta Crantz).

    Science.gov (United States)

    Pootakham, Wirulda; Shearman, Jeremy R; Ruang-Areerate, Panthita; Sonthirod, Chutima; Sangsrakru, Duangjai; Jomchai, Nukoon; Yoocha, Thippawan; Triwitayakorn, Kanokporn; Tragoonrung, Somvong; Tangphatsornruang, Sithichoke

    2014-01-01

    Cassava (Manihot esculenta Crantz) is one of the most important crop species being the main source of dietary energy in several countries. Marker-assisted selection has become an essential tool in plant breeding. Single nucleotide polymorphism (SNP) discovery via transcriptome sequencing is an attractive strategy for genome complexity reduction in organisms with large genomes. We sequenced the transcriptome of 16 cassava accessions using the Illumina HiSeq platform and identified 675,559 EST-derived SNP markers. A subset of those markers was subsequently genotyped by capture-based targeted enrichment sequencing in 100 F1 progeny segregating for starch viscosity phenotypes. A total of 2,110 non-redundant SNP markers were used to construct a genetic map. This map encompasses 1,785 cM and consists of 19 linkage groups. A major quantitative trait locus (QTL) controlling starch pasting properties was identified and shown to coincide with the QTL previously reported for this trait. With a high-density SNP-based linkage map presented here, we also uncovered a novel QTL associated with starch pasting time on LG 10.

  6. Consumer preferences for table cassava characteristics in Pernambuco, Brazil

    OpenAIRE

    Gonzalez, Carolina; Johnson, Nancy L.

    2009-01-01

    Cassava is a major source of carbohydrate for populations in the tropics; however, there is little information about the preferences of consumers toward the quality characteristics of this crop. This paper analyzes the demand for different cassava attributes, and applies the hedonic price method to estimate the values that consumers give to implicit attributes of cassava. The results show that ease of peeling, time of cooking and texture of cassava are the most important characteristics consu...

  7. Starch nanoparticles: a review.

    Science.gov (United States)

    Le Corre, Déborah; Bras, Julien; Dufresne, Alain

    2010-05-10

    Starch is a natural, renewable, and biodegradable polymer produced by many plants as a source of stored energy. It is the second most abundant biomass material in nature. The starch structure has been under research for years, and because of its complexity, an universally accepted model is still lacking (Buleon, A.; et al. Int. J. Biol. Macromol. 1998, 23, 85-112). However, the predominant model for starch is a concentric semicrystalline multiscale structure that allows the production of new nanoelements: (i) starch nanocrystals resulting from the disruption of amorphous domains from semicrystalline granules by acid hydrolysis and (ii) starch nanoparticles produced from gelatinized starch. This paper intends to give a clear overview of starch nanoparticle preparation, characterization, properties, and applications. Recent studies have shown that they could be used as fillers to improve mechanical and barrier properties of biocomposites. Their use for industrial packaging, continuously looking for innovative solutions for efficient and sustainable systems, is being investigated. Therefore, recently, starch nanoparticles have been the focus of an exponentially increasing number of works devoted to develop biocomposites by blending starch nanoparticles with different biopolymeric matrices. To our knowledge, this topic has never been reviewed, despite several published strategies and conclusions. PMID:20405913

  8. Xylitol production from wheat straw hemicellulosic hydrolysate: hydrolysate detoxification and carbon source used for inoculum preparation

    OpenAIRE

    Canilha, Larissa; Carvalho, Walter; Felipe, Maria das Graças Almeida; de Almeida e Silva, João Batista

    2008-01-01

    Wheat straw hemicellulosic hydrolysate was used for xylitol bioproduction. The use of a xylose-containing medium to grow the inoculum did not favor the production of xylitol in the hydrolysate, which was submitted to a previous detoxification treatment with 2.5% activated charcoal for optimized removal of inhibitory compounds.

  9. Xylitol production from wheat straw hemicellulosic hydrolysate: hydrolysate detoxification and carbon source used for inoculum preparation

    Science.gov (United States)

    Canilha, Larissa; Carvalho, Walter; Felipe, Maria das Graças Almeida; de Almeida e Silva, João Batista

    2008-01-01

    Wheat straw hemicellulosic hydrolysate was used for xylitol bioproduction. The use of a xylose-containing medium to grow the inoculum did not favor the production of xylitol in the hydrolysate, which was submitted to a previous detoxification treatment with 2.5% activated charcoal for optimized removal of inhibitory compounds. PMID:24031226

  10. Enzymatic hydrolysis of potato starch and ethanol production

    OpenAIRE

    Lazić Miodrag L.; Rašković Suzana; Stanković Mihajlo Z.; Veljković Vlada B.

    2004-01-01

    The hydrolysis of potato starch using one (Termamyl or Fungamyl) and two combined (Termamyl and Supersan) commercial enzyme preparations and ethanol production from the hydrolysates obtained using the yeast Saccharomyces cerevisiae were studied. Potato tubers were previously prepared as mash or flour. The study dealt with the effects of the hydromodulus (1:1 and 1:0.5), particle size (0.1, 0.2 and 0.4 mm) as well as the type and concentration of enzyme on the enzymatic hydrolysis of potato st...

  11. Phenotypic Approaches to Drought in Cassava: Review

    Directory of Open Access Journals (Sweden)

    Emmanuel eOkogbenin

    2013-05-01

    Full Text Available Cassava is an important crop in Africa, Asia, Latin America and the Caribbean. Cassava can be produced adequately in drought conditions making it the ideal food security crop in marginal environments. Although cassava can tolerate drought stress, it can be genetically improved to enhance productivity in such environments. Drought adaptation studies in over three decades in cassava have identified relevant mechanisms which have been explored in conventional breeding. Drought is a quantitative trait and its multigenic nature makes it very challenging to effectively manipulate and combine genes in breeding for rapid genetic gain and selection process. Cassava has a long growth cycle of 12 - 18 months which invariably contributes to a long breeding scheme for the crop. Modern breeding using advances in genomics and improved genotyping, is facilitating the dissection and genetic analysis of complex traits including drought tolerance, thus helping to better elucidate and understand the genetic basis of such traits. A beneficial goal of new innovative breeding strategies is to shorten the breeding cycle using minimized, efficient or fast phenotyping protocols. While high throughput genotyping have been achieved, this is rarely the case for phenotyping for drought adaptation. Some of the storage root phenotyping in cassava are often done very late in the evaluation cycle making selection process very slow. This paper highlights some modified traits suitable for early-growth phase phenotyping that may be used to reduce drought phenotyping cycle in cassava. Such modified traits can significantly complement the high throughput genotyping procedures to fast track breeding of improved drought tolerant varieties. The need for metabolite profiling, improved phenomics to take advantage of next generation sequencing technologies and high throughput phenotyping are basic steps for future direction to improve genetic gain and maximize speed for drought tolerance

  12. Phenotypic approaches to drought in cassava: review.

    Science.gov (United States)

    Okogbenin, Emmanuel; Setter, Tim L; Ferguson, Morag; Mutegi, Rose; Ceballos, Hernan; Olasanmi, Bunmi; Fregene, Martin

    2013-01-01

    Cassava is an important crop in Africa, Asia, Latin America, and the Caribbean. Cassava can be produced adequately in drought conditions making it the ideal food security crop in marginal environments. Although cassava can tolerate drought stress, it can be genetically improved to enhance productivity in such environments. Drought adaptation studies in over three decades in cassava have identified relevant mechanisms which have been explored in conventional breeding. Drought is a quantitative trait and its multigenic nature makes it very challenging to effectively manipulate and combine genes in breeding for rapid genetic gain and selection process. Cassava has a long growth cycle of 12-18 months which invariably contributes to a long breeding scheme for the crop. Modern breeding using advances in genomics and improved genotyping, is facilitating the dissection and genetic analysis of complex traits including drought tolerance, thus helping to better elucidate and understand the genetic basis of such traits. A beneficial goal of new innovative breeding strategies is to shorten the breeding cycle using minimized, efficient or fast phenotyping protocols. While high throughput genotyping have been achieved, this is rarely the case for phenotyping for drought adaptation. Some of the storage root phenotyping in cassava are often done very late in the evaluation cycle making selection process very slow. This paper highlights some modified traits suitable for early-growth phase phenotyping that may be used to reduce drought phenotyping cycle in cassava. Such modified traits can significantly complement the high throughput genotyping procedures to fast track breeding of improved drought tolerant varieties. The need for metabolite profiling, improved phenomics to take advantage of next generation sequencing technologies and high throughput phenotyping are basic steps for future direction to improve genetic gain and maximize speed for drought tolerance breeding. PMID

  13. Biodegradable foams based on starch, polyvinyl alcohol, chitosan and sugarcane fibers obtained by extrusion

    Directory of Open Access Journals (Sweden)

    Flávia Debiagi

    2011-10-01

    Full Text Available Biodegradable foams made from cassava starch, polyvinyl alcohol (PVA, sugarcane bagasse fibers and chitosan were obtained by extrusion. The composites were prepared with formulations determined by a constrained ternary mixtures experimental design, using as variables: (X1 starch / PVA (100 - 70%, (X2 chitosan (0 - 2% and (X3 fibers from sugar cane (0 - 28%. The effects of varying proportions of these three components on foam properties were studied, as well the relationship between their properties and foam microstructure. The addition of starch/PVA in high proportions increased the expansion index and mechanical resistance of studied foams. Fibers addition improved the expansion and mechanical properties of the foams. There was a trend of red and yellow colors when the composites were produced with the highest proportions of fibers and chitosan, respectively. All the formulations were resistant to moisture content increase until 75% relative humidity of storage.

  14. Domain C of thermostable α-amylase of Geobacillus thermoleovorans mediates raw starch adsorption.

    Science.gov (United States)

    Mehta, Deepika; Satyanarayana, T

    2014-05-01

    The gene (1,542 bp) encoding thermostable Ca(2+)-independent and raw starch hydrolyzing α-amylase of the extremely thermophilic bacterium Geobacillus thermoleovorans encodes for a protein of 50 kDa (Gt-amyII) with 488 amino acids. The enzyme is optimally active at pH 7.0 and 60 °C with a t 1/2 of 19.4 h at 60 and 4 h at 70 °C. Gt-amyII hydrolyses corn and tapioca raw starches efficiently and therefore finds application in starch saccharification at industrial sub-gelatinisation temperatures. The starch hydrolysis is facilitated following adsorption of the enzyme to starch at the C-terminal domain, as confirmed by the truncation analysis. The adsorption rate constant of Gt-amyII to raw corn starch is 37.6-fold greater than that for the C-terminus truncated enzyme (Gt-amyII-T). Langmuir-Hinshelwood kinetic analysis in terms of equilibrium parameter (K R) suggested that the adsorption of Gt-amyII to corn starch is more favourable than that of Gt-amyII-T. Thermodynamics of temperature inactivation indicated a decrease in thermostabilisation of Gt-amyII upon truncation of its C-terminus. The addition of raw corn starch increased t 1/2 of Gt-amyII, but it has no such effect on Gt-amyII-T. It can, therefore, be stated that Gt-amyII binds to raw corn starch via C-terminal region that contributes to its thermostability. Phylogenetic analysis confirmed that starch binding region of Gt-amyII is, in fact, the non-catalytic domain C, and not the typical SBD of CBM families. The role of domain C in raw starch binding throws light on the evolutionary path of the known SBDs.

  15. Exploration and Research on the Preparation of Ethanol by Cassava Residue%木薯渣制备乙醇探索研究

    Institute of Scientific and Technical Information of China (English)

    赵晓锋; 张全; 姚秀清; 关浩; 佟明友

    2012-01-01

    [目的]对木薯渣水解糖发酵制乙醇的再利用过程进行考察.[方法]以木薯渣为原料,采用同步糖化发酵工艺,研究木薯渣中淀粉、纤维素和半纤维素术解糖分开发酵或共同发酵制乙醇的过程.[结果]原料中纤维素含量为34.70%,半纤维素含量为9.70%,淀粉含量为15.35%;采用同步糖化共发酵工艺较同步糖化分开发酵工艺,乙醇相对于原料的产率高,可达到28.04%.[结论]该研究可为术薯渣的合理利用提供技术支持.%[ Objective] To investigate the ethanol preparation from the fermentation of cassava residue. [ Method] The simultaneous saccharifiea- tion and fermentation (SSF) technology was applied to study the separate fermentation and co-fermentation of the fermentable sugar from starch, cellulose and hemicellulose in cassava residue. [ Result] The content of cellulose, hemicellulose and starch in cassava residue were 34. 70% , 9.70% and 15.35% respectively, and the ethanol yield related to cassava residue achieved by co-fermentation process was 28.04% , which was higher compared with separate fermentation process. [Conclusion] The study provides technical support for the reasonable utilization of cassava residue.

  16. An atlas of cassava in Africa : historical, agroecological and demographic aspects of crop distribution

    NARCIS (Netherlands)

    Carter, S.; Fresco, L.O.; Jones, P.

    1992-01-01

    This book contains 6 chapters covering: the dynamics of cassava in Africa; the introduction and diffusion of cassava in Africa; current distribution of cassava in Africa; the relationship of cassava distribution to environment and population; distribution and change in cassava production in Nigeria,

  17. Chlorophyll and starch assays

    OpenAIRE

    sprotocols

    2015-01-01

    Chlorophyll, starch, and sugar contents are good indicators of growth vigor in plants. To measure the chlorophyll content, we used a modified protocol (1,2). The starch content was determined using iodine staining (3) and enzymatic reactions (4-6).

  18. Sequences enhancing cassava mosaic disease symptoms occur in the cassava genome and are associated with South African cassava mosaic virus infection.

    Science.gov (United States)

    Maredza, A T; Allie, F; Plata, G; Rey, M E C

    2016-06-01

    Cassava is an important food security crop in Sub-Saharan Africa. Two episomal begomovirus-associated sequences, named Sequences Enhancing Geminivirus Symptoms (SEGS1 and SEGS2), were identified in field cassava affected by the devastating cassava mosaic disease (CMD). The sequences reportedly exacerbated CMD symptoms in the tolerant cassava landrace TME3, and the model plants Arabidopsis thaliana and Nicotiana benthamiana, when biolistically co-inoculated with African cassava mosaic virus-Cameroon (ACMV-CM) or East African cassava mosaic virus-UG2 (EACMV-UG2). Following the identification of small SEGS fragments in the cassava EST database, the intention of this study was to confirm their presence in the genome, and investigate a possible role for these sequences in CMD. We report that multiple copies of varying lengths of both SEGS1 and SEGS2 are widely distributed in the sequenced cassava genome and are present in several other cassava accessions screened by PCR. The endogenous SEGS1 and SEGS2 are in close proximity or overlapping with cassava genes, suggesting a possible role in regulation of specific biological processes. We confirm the expression of SEGS in planta using EST data and RT-PCR. The sequence features of endogenous SEGS (iSEGS) are unique but resemble non-autonomous transposable elements (TEs) such as MITEs and helitrons. Furthermore, many SEGS-associated genes, some involved in virus-host interactions, are differentially expressed in susceptible (T200) and tolerant TME3) cassava landraces infected by South African cassava mosaic virus (SACMV) of susceptible (T200) and tolerant (TME3) cassava landraces. Abundant SEGS-derived small RNAs were also present in mock-inoculated and SACMV-infected T200 and TME3 leaves. Given the known role of TEs and associated genes in gene regulation and plant immune responses, our observations are consistent with a role of these DNA elements in the host's regulatory response to geminiviruses.

  19. Sequences enhancing cassava mosaic disease symptoms occur in the cassava genome and are associated with South African cassava mosaic virus infection.

    Science.gov (United States)

    Maredza, A T; Allie, F; Plata, G; Rey, M E C

    2016-06-01

    Cassava is an important food security crop in Sub-Saharan Africa. Two episomal begomovirus-associated sequences, named Sequences Enhancing Geminivirus Symptoms (SEGS1 and SEGS2), were identified in field cassava affected by the devastating cassava mosaic disease (CMD). The sequences reportedly exacerbated CMD symptoms in the tolerant cassava landrace TME3, and the model plants Arabidopsis thaliana and Nicotiana benthamiana, when biolistically co-inoculated with African cassava mosaic virus-Cameroon (ACMV-CM) or East African cassava mosaic virus-UG2 (EACMV-UG2). Following the identification of small SEGS fragments in the cassava EST database, the intention of this study was to confirm their presence in the genome, and investigate a possible role for these sequences in CMD. We report that multiple copies of varying lengths of both SEGS1 and SEGS2 are widely distributed in the sequenced cassava genome and are present in several other cassava accessions screened by PCR. The endogenous SEGS1 and SEGS2 are in close proximity or overlapping with cassava genes, suggesting a possible role in regulation of specific biological processes. We confirm the expression of SEGS in planta using EST data and RT-PCR. The sequence features of endogenous SEGS (iSEGS) are unique but resemble non-autonomous transposable elements (TEs) such as MITEs and helitrons. Furthermore, many SEGS-associated genes, some involved in virus-host interactions, are differentially expressed in susceptible (T200) and tolerant TME3) cassava landraces infected by South African cassava mosaic virus (SACMV) of susceptible (T200) and tolerant (TME3) cassava landraces. Abundant SEGS-derived small RNAs were also present in mock-inoculated and SACMV-infected T200 and TME3 leaves. Given the known role of TEs and associated genes in gene regulation and plant immune responses, our observations are consistent with a role of these DNA elements in the host's regulatory response to geminiviruses. PMID:25920485

  20. Improvement of cassava for resistance to insect pests and diseases

    International Nuclear Information System (INIS)

    The African cassava mosaic virus and cassava mealybug are devastating the cassava crop in Uganda. Because of the severe widespread occurrence of the virus and mealybug, in vitro cultured cassava plantlets instead of stem cuttings will be irradiated. In addition, the project has incorporated sweet potato. Installation of tissue culture laboratory at Namulonge was completed in early 1993. Work is in progress to establish efficient in vitro culture micropropagation techniques for the two crops. Small numbers of cassava plantlets of varieties 'TMS 30337' and 'TMS 4(2)1425' and sweet potato entry 30 are in vitro culture. Mass irradiation of plantlets is planned in future. (author). 4 refs

  1. Gene expression of beta carotene genes in transgenic biofortified cassava

    OpenAIRE

    Telengech, P. K.; Maling’a, J. N.; Nyende, A. B.; Gichuki, S. T.; Wanjala, B. W.

    2014-01-01

    Cassava is an important food for millions of people around the world. However, cassava is deficient in protein, iron, zinc, pro-vitamin A and vitamin E. Cassava biofortified with pro-vitamin A can help reduce Vitamin A Deficiency among the undernourished communities that rely upon it for sustenance. BioCassava Plus project has developed transgenic cassava that expresses beta carotene in roots using root specific patatin promoter. This study aimed at confirming expression of nptII, crtB and DX...

  2. Study of Products Distilled Spirits with Cassava Dregs

    Institute of Scientific and Technical Information of China (English)

    WANG le; WANG Jun-gao; LIU Wen-long

    2009-01-01

    In this paper, Cassava dregs are an outgrowth produced during starchy production which uses cassava as raw material. It is usually dropped out or used as cheap feedstuff. In order to make the best use of cassava dregs, increase industries' benefits and reduce castoff this study developed a new technique which used cassava dregs as raw material to produce distilled spirits based on cassava dregs characteristics. The technique adopt solid-ferment procedure. At first, the ferment is processed by solid-state distilling, and then rectification extra care refinement: at last the tequila was produced with characteristics of simple and elegant fragrance and mellow-tasting.

  3. State of the Art Manufacturing of Protein Hydrolysates

    Science.gov (United States)

    Pasupuleti, Vijai K.; Braun, Steven

    The use of protein hydrolysates in microbiological media has been in existence for several decades and the basic manufacturing process of protein hydrolysates has remained the same. However, with increasing use of protein hydrolysates in specialized applications such as animal cell culture processes, the manufacturing of protein hydrolysates has dramatically improved and is still in its infancy to uncover the specific peptide, peptides and combination of individual amino acids that produce intended effects for that application. This will change as the protein hydrolysate manufacturers and end-users exchange information and work towards the common goal of developing the best protein hydrolysates for specific applications. This chapter will review the generic manufacturing of protein hydrolysates describing individual unit operations, problems faced by manufacturers and suggestions for obtaining consistent product and guidelines for the end-users in getting regulatory support and setting up reliable specifications. Finally the chapter concludes with future trends of protein hydrolysates.

  4. The activity of barley alpha-amylase on starch granules is enhanced by fusion of a starch binding domain from Aspergillus niger glucoamylase

    DEFF Research Database (Denmark)

    Juge, N.; Nøhr, J.; Le Gal-Coëffet, M.-F.;

    2006-01-01

    High affinity for starch granules of certain amylolytic enzymes is mediated by a separate starch binding domain (SBD). In Aspergillus niger glucoamylase (GA-I), a 70 amino acid O-glycosylated peptide linker connects SBD with the catalytic domain. A gene was constructed to encode barley alpha...... of isoelectric points in the range 4.1-5.2. Activity and apparent affinity of AMY1-SBD (50 nM) for barley starch granules of 0.034 U x nmol(-1) and K(d) = 0.13 mg x mL(-1), respectively, were both improved with respect to the values 0.015 U x nmol(-1) and 0.67 mg x mL(-1) for rAMY1 (recombinant AMY1 produced...... in A. niger). AMY1-SBD showed a 2-fold increased activity for soluble starch at low (0.5%) but not at high (1%) concentration. AMY1-SBD hydrolysed amylose DP440 with an increased degree of multiple attack of 3 compared to 1.9 for rAMY1. Remarkably, at low concentration (2 nM), AMY1-SBD hydrolysed...

  5. Chemical safety of cassava products in regions adopting cassava production and processing - experience from Southern Africa

    DEFF Research Database (Denmark)

    Nyirenda, D.B.; Chiwona-Karltun, L.; Chitundu, M.;

    2011-01-01

    The cassava belt area in Southern Africa is experiencing an unforeseen surge in cassava production, processing and consumption. Little documentation exists on the effects of this surge on processing procedures, the prevailing levels of cyanogenic glucosides of products consumed and the levels...... and perceptions concerning cassava and chemical food safety. Chips, mixed biscuits and flour, procured from households and markets in three regions of Zambia (Luapula-North, Western and Southern) as well as products from the Northern, Central and Southern regions of Malawi, were analyzed for total cyanogenic...

  6. A single-tube duplex and multiplex PCR for simultaneous detection of four cassava mosaic begomovirus species in cassava plants.

    Science.gov (United States)

    Aloyce, R C; Tairo, F; Sseruwagi, P; Rey, M E C; Ndunguru, J

    2013-04-01

    A single-tube duplex and multiplex PCR was developed for the simultaneous detection of African cassava mosaic virus (ACMV), East African cassava mosaic Cameroon virus (EACMCV), East African cassava mosaic Malawi virus (EACMMV) and East African cassava mosaic Zanzibar virus (EACMZV), four cassava mosaic begomoviruses (CMBs) affecting cassava in sub-Saharan Africa. Co-occurrence of the CMBs in cassava synergistically enhances disease symptoms and complicates their detection and diagnostics. Four primer pairs were designed to target DNA-A component sequences of cassava begomoviruses in a single tube PCR amplification using DNA extracted from dry-stored cassava leaves. Duplex and multiplex PCR enabled the simultaneous detection and differentiation of the four CMBs, namely ACMV (940bp), EACMCV (435bp), EACMMV (504bp) and EACMZV (260bp) in single and mixed infections, and sequencing results confirmed virus identities according to the respective published sequences of begomovirus species. In addition, we report here a modified Dellapotra et al. (1983) protocol, which was used to extract DNA from dry and fresh cassava leaves with comparable results. Using the duplex and multiplex techniques, time was saved and amount of reagents used were reduced, which translated into reduced cost of the diagnostics. This tool can be used by cassava breeders screening for disease resistance; scientists doing virus diagnostic studies; phytosanitary officers checking movement of diseased planting materials, and seed certification and multipliers for virus indexing.

  7. Biofunctional Properties of Enzymatic Squid Meat Hydrolysate

    OpenAIRE

    Choi, Joon Hyuk; Kim, Kyung-Tae; Kim, Sang Moo

    2015-01-01

    Squid is one of the most important commercial fishes in the world and is mainly utilized or consumed as sliced raw fish or as processed products. The biofunctional activities of enzymatic squid meat hydrolysate were determined to develop value-added products. Enzymatic squid hydrolysate manufactured by Alcalase effectively quenched 1,1-diphenyl-2-picrylhydrazyl radical, hydroxyl radical, and hydrogen peroxide radical with IC50 values of 311, 3,410, and 111.5 μg/mL, respectively. Angiotensin I...

  8. Food-starch granulomatous peritonitis.

    OpenAIRE

    Davies, J D; Ansell, I D

    1983-01-01

    Two cases of peritoneal granulomatous reactions to food starch are described. They followed bowel perforation and clinically mimicked tuberculous and glove-powder starch peritonitis. Their histological differences from corn-starch peritonitis warrant attention in the absence of previous documentation of starch as a component of peritoneal food granulomas. Food-starch granules tend to be larger than those of glove powder, are often oval, and may be extremely resistant to salivary diastase dige...

  9. Induction and Identification of Useful Mutations for Root Quality Traits in Cassava

    International Nuclear Information System (INIS)

    A population of about 1,500 M2 genotypes (from five different cassava families), were screened for relevant traits. Roots could be harvested from 800 of these genotypes and thoroughly screened for starch quality traits. Four distinctive phenotypes were identified: a small granule, high-amylose starch mutation with almost no paste viscosity, a group of genotypes with tolerance to post-harvest physiological deterioration, a 'hollow' starch granule mutation with intermediate viscosity peaks, and a group of genotypes with a starchless (potentially 'sugary') root mutation. The last two mutations need to be further characterized and confirmed. The small granule mutation has been fully characterized and a lesion in the isoamylase one or two loci has been postulated to be the most likely site. The frequency of this mutation (present in two lineages out of the 800 M2 genotypes analyzed) suggests that mutation at the putative locus is easy to attain, or else that the repair mechanisms are less efficient at that site. Several of these unusual phenotypes identified offer important commercial advantages. (author)

  10. Emergence of a Latent Indian Cassava Mosaic Virus from Cassava Which Recovered from Infection by a Non-Persistent Sri Lankan Cassava Mosaic Virus

    Science.gov (United States)

    Karthikeyan, Chockalingam; Patil, Basavaprabhu L.; Borah, Basanta K.; Resmi, Thulasi R.; Turco, Silvia; Pooggin, Mikhail M.; Hohn, Thomas; Veluthambi, Karuppannan

    2016-01-01

    The major threat for cassava cultivation on the Indian subcontinent is cassava mosaic disease (CMD) caused by cassava mosaic geminiviruses which are bipartite begomoviruses with DNA A and DNA B components. Indian cassava mosaic virus (ICMV) and Sri Lankan cassava mosaic virus (SLCMV) cause CMD in India. Two isolates of SLCMV infected the cassava cultivar Sengutchi in the fields near Malappuram and Thiruvananthapuram cities of Kerala State, India. The Malappuram isolate was persistent when maintained in the Madurai Kamaraj University (MKU, Madurai, Tamil Nadu, India) greenhouse, whereas the Thiruvananthapuram isolate did not persist. The recovered cassava plants with the non-persistent SLCMV, which were maintained vegetative in quarantine in the University of Basel (Basel, Switzerland) greenhouse, displayed re-emergence of CMD after a six-month period. Interestingly, these plants did not carry SLCMV but carried ICMV. It is interpreted that the field-collected, SLCMV-infected cassava plants were co-infected with low levels of ICMV. The loss of SLCMV in recovered cassava plants, under greenhouse conditions, then facilitated the re-emergence of ICMV. The partial dimer clones of the persistent and non-persistent isolates of SLCMV and the re-emerged isolate of ICMV were infective in Nicotiana benthamiana upon agroinoculation. Studies on pseudo-recombination between SLCMV and ICMV in N. benthamiana provided evidence for trans-replication of ICMV DNA B by SLCMV DNA A. PMID:27690084

  11. Hyperglycemic effect of low protein cassava diet.

    Science.gov (United States)

    Sreeja, V G; Leelamma, S

    1998-03-01

    Hyperglycemic effect of cassava diet in presence of varying amounts of protein has been carried out. The rats fed a low protein high cyanide diet showed an increase in the blood glucose and a decrease in the liver glycogen. The activity of glycogen phosphorylase, glucose 6-phosphatase and phosphoglucomutase showed higher levels in the liver of low protein high cyanide group compared to the control group. Also, the activity of hexokinase, and isocitrate dehydrogenase activity in the liver of high cyanide low protein were significantly low. The results suggests that cassava diet with the low protein can induce hyperglycemia. PMID:9754064

  12. Microbial degradation and utilization of cassava peel.

    Science.gov (United States)

    Ofuya, C O; Nwajiuba, C J

    1990-06-01

    Cassava peel was readily degraded and utilized by a strain ofRhizopus growing in a solid-state fermentation. Growth was maximal at 45°C and was proportional to the degree of hydrolysis of the peel. The yield of biomass, as weight of dry mycellum from the reducing sugars of the peel, was 51%. After 72 h fermentation, the peel contained 76% moisture, 6% cellulose, 7% hemicellulose and 0.4% ash and the protein content had increased from 5.6% to 16%. These results suggest a possible economic value of cassava peel in the production of fungal biomass and feedstock.

  13. SCREENING OF CHEMICAL COMPOSITIONS OF CRUDE WATER EXTRACT OF DIFFERENT CASSAVA VARIETIES

    OpenAIRE

    Olajumoke Oke FAYINMINNU; Olubunmi Omowunmi FADINA; Alex Adeoluwa ADEDAPO

    2013-01-01

    Chemical composition of three sources of crude cassava water extract (CCWE) was evaluated in different varieties of cassava (MS6 Manihot Selection (local variety), TMS 30555 Tropical Manihot Selection (Improved variety) and Bulk (crude cassava water from cassava processing site). Crude cassava water extract from the pulp of cassava fresh roots was prepared and the chemical composition was determined in the analytical laboratory. The result of the analysis showed that, hydrocyanic acid (HCN) ...

  14. Biochemical Characterization of the Lactobacillus reuteri Glycoside Hydrolase Family 70 GTFB Type of 4,6-α-Glucanotransferase Enzymes That Synthesize Soluble Dietary Starch Fibers

    OpenAIRE

    Bai, Yuxiang; Kaaij, Rachel Maria van der; Leemhuis, Hans; Pijning, Tjaard; van Leeuwen, Sander Sebastiaan; Jin, Zhengyu; Dijkhuizen, Lubbert

    2015-01-01

    4,6-α-Glucanotransferase (4,6-α-GTase) enzymes, such as GTFB and GTFW of Lactobacillus reuteri strains, constitute a new reaction specificity in glycoside hydrolase family 70 (GH70) and are novel enzymes that convert starch or starch hydrolysates into isomalto/maltopolysaccharides (IMMPs). These IMMPs still have linear chains with some α1→4 linkages but mostly (relatively long) linear chains with α1→6 linkages and are soluble dietary