Study on the mould-resistant properties of moso bamboo treated with high pressure and amylase

Science.gov (United States)

Xiao-Dong Huang; Chung-Yun Hse; Todd F. Shupe

2014-01-01

Starch of moso bamboo mainly exists in the elongated parenchyma cells, and it is difficult for amylase to enter moso bamboo and dissolve the starch. Therefore, the mould resistance capability of moso bamboo's products cannot meet the need for bamboo to resist fungal decay. In this experiment, moso bamboo blocks were first treated at six levels of pressure and for...

Mammalian Mucosal ?-Glucosidases Coordinate with ?-Amylase in the Initial Starch Hydrolysis Stage to Have a Role in Starch Digestion beyond Glucogenesis

OpenAIRE

Dhital, Sushil; Lin, Amy Hui-Mei; Hamaker, Bruce R.; Gidley, Michael J.; Muniandy, Anbuhkani

2013-01-01

Starch digestion in the human body is typically viewed in a sequential manner beginning with α-amylase and followed by α-glucosidase to produce glucose. This report indicates that the two enzyme types can act synergistically to digest granular starch structure. The aim of this study was to investigate how the mucosal α-glucosidases act with α-amylase to digest granular starch. Two types of enzyme extracts, pancreatic and intestinal extracts, were applied. The pancreatic extract containing pre...

Improvement of Raw-Starch Digestibility of Amylase from Aspergillus awamori by Gamma Radiation Mutation for Alcohol Production

International Nuclear Information System (INIS)

Kanlayakrit, Werasit; Piadang, Nattayana; Maweang, Metinee

2006-09-01

Aspergillus awamori was induced to mutation by gamma ray to improve raw-starch digestibility of amylase enzyme. Twenty fungal colonies were selected base on and amylase and glucoamylase activities including raw starch digestibility. The result showed that isolate A a(i)-2(16) was the best isolate for raw-starch digestion (65.64 %). It produced extracellular amylase enzyme which showed highest raw-starch digestibility more than wild type about 2 folds. Based on enzymes from solid culture showed activities higher from liquid medium. Therefore solid culture is suitable for fungal enzyme production.

Study on the Mould-Resistant Properties of Moso Bamboo Treated with High Pressure and Amylase

Directory of Open Access Journals (Sweden)

Xiao-Dong Huang

2013-11-01

Full Text Available Starch of moso bamboo mainly exists in the elongated parenchyma cells, and it is difficult for amylase to enter moso bamboo and dissolve the starch. Therefore, the mould resistance capability of moso bamboo’s products cannot meet the need for bamboo to resist fungal decay. In this experiment, moso bamboo blocks were first treated at six levels of pressure and for six different treatment durations. The results showed that reducing sugar content was decreased dramatically from 0.92 mg/L to 0.19 mg/L and the starch content decreased from 1.18% to 0.96% when the pressure was increased from 0 psi to 100 psi. Regression analysis showed that the effects of an individual amylase reaction and individual pressure treatment on the starch or reducing sugar content were significant with a high correlation coefficient. Three traditional types of moso bamboo moulds (Aspergillus niger, Penicillium citrinum, and Trichoderma viride were then used for mould resistance testing. The results revealed that the mould resistance capability of moso bamboo blocks could be greatly improved by the combined effect of enzyme activity and pressure treatment. Mould resistance was enhanced by increasing the pressure or prolonging the treatment time. This research could provide a new method for the protection of bamboo from mould attack.

Carbohydrates, Dietary Fiber, and Resistant Starch in White Vegetables: Links to Health Outcomes12

OpenAIRE

Slavin, Joanne L.

2013-01-01

Vegetables are universally promoted as healthy. Dietary Guidelines for Americans 2010 recommend that you make half of your plate fruits and vegetables. Vegetables are diverse plants that vary greatly in energy content and nutrients. Vegetables supply carbohydrates, dietary fiber, and resistant starch in the diet, all of which have been linked to positive health outcomes. Fiber lowers the incidence of cardiovascular disease and obesity. In this paper, the important role of white vegetables in ...

Complete starch hydrolysis by the synergistic action of amylase and glucoamylase: impact of calcium ions.

Science.gov (United States)

Presečki, Ana Vrsalović; Blažević, Zvjezdana Findrik; Vasić-Rački, Durđa

2013-11-01

Starch hydrolysis was performed by the synergistic action of amylase and glucoamylase. For that purpose glucoamylase (Dextrozyme) and two amylases (Liquozyme and Termamyl) in different combinations were investigated. Experiments were carried out in the repetitive- and fed-batch modes at 65 °C and pH 5.5 with and without the addition of Ca(2+) ions. 100 % conversion of starch to glucose was achieved in batch experiments. Calcium ions significantly enhanced stability of the amylase Termamyl. The intensity of synergism between amylase Termamyl and glucoamylase Dextrozyme was higher than in the experiments carried out with amylase Liquozyme and Dextrozyme. Mathematical model of the complete reaction system was developed. Using the model, a possible explanation of the synergism between the amylase and glucoamylase was provided.

Amylase activity of a starch degrading bacteria isolated from soil ...

African Journals Online (AJOL)

STORAGESEVER

2008-09-17

Sep 17, 2008 ... Key words: Amylase, Bacillus, kitchen waste, starch degrading. INTRODUCTION ... several sources such as plant, animal and microbes. (Kathiresan .... Test. Response of the strain. Gram's staining. +. Shape. Bacilli. Motility. +.

Determination of dietary starch in animal feeds and pet food by an enzymatic-colorimetric method: collaborative study.

Science.gov (United States)

Hall, Mary Beth

2015-01-01

Starch, glycogen, maltooligosaccharides, and other α-1,4- and α-1,6-linked glucose carbohydrates, exclusive of resistant starch, are collectively termed "dietary starch". This nutritionally important fraction is increasingly measured for use in diet formulation for animals as it can have positive or negative effects on animal performance and health by affecting energy supply, glycemic index, and formation of fermentation products by gut microbes. AOAC Method 920.40 that was used for measuring dietary starch in animal feeds was invalidated due to discontinued production of a required enzyme. As a replacement, an enzymatic-colorimetric starch assay developed in 1997 that had advantages in ease of sample handling and accuracy compared to other methods was considered. The assay was further modified to improve utilization of laboratory resources and reduce time required for the assay. The assay is quasi-empirical: glucose is the analyte detected, but its release is determined by run conditions and specification of enzymes. The modified assay was tested in an AOAC collaborative study to evaluate its accuracy and reliability for determination of dietary starch in animal feedstuffs and pet foods. In the assay, samples are incubated in screw cap tubes with thermostable α-amylase in pH 5.0 sodium acetate buffer for 1 h at 100°C with periodic mixing to gelatinize and partially hydrolyze α-glucan. Amyloglucosidase is added, and the reaction mixture is incubated at 50°C for 2 h and mixed once. After subsequent addition of water, mixing, clarification, and dilution as needed, free + enzymatically released glucose are measured. Values from a separate determination of free glucose are subtracted to give values for enzymatically released glucose. Dietary starch equals enzymatically released glucose multiplied by 162/180 (or 0.9) divided by the weight of the as received sample. Fifteen laboratories that represented feed company, regulatory, research, and commercial feed

Polymeric amylase nanoparticles as a new semi-synthetic enzyme system for hydrolysis of starch

International Nuclear Information System (INIS)

Say, R.; Şenay, R. Hilal; Biçen, Özlem; Ersöz, Arzu; Şişman Yılmaz, Filiz; Akgöl, Sinan; Denizli, Adil

2013-01-01

α-Amylase (EC 3.2.1.1; α-D-1,4,glucan glucanohydrolase) catalyzes the hydrolysis of α-D-(1,4)-glucosidic linkages in starch, glycogen, and various malto-oligosaccharides, by releasing α-anomeric products. In this study, a novel method has been developed to prepare nanoprotein particles that carry α-amylase as a monomer by using a photosensitive microemulsion polymerization process. The nanostructured α-amylase with photosensitive features have been characterized by fluorescence spectroscopy, transmission electron microscopy (TEM) and Zeta Sizer. The fluorescence intensity of amylase nanoparticles was determined to be 658 a.u. at 610 nm and the average particle size of nanoamylase was found to be about 71.8 nm. Both free α-amylase and nanoparticles were used in the hydrolysis of starch under varying reaction conditions such as pH and temperature that affect enzyme activity and the results were compared to each other. K m values were 0.26 and 0.87 mM and V max values were 0.36 IU mg −1 and 22.32 IU mg −1 for nanoenzyme and free enzyme, respectively. Then, thermal stability, storage stability and reusability were investigated and according to the results, activity was preserved 60% at 60 °C; 20% at 70–80 °C temperature values and 80% after 105 days storage. Finally after 10 cycles, the activity was preserved 90% and this novel enzymatic polymeric amylase nanoparticle has showed considerable potential as reusable catalyst. - Highlights: ► Developing to prepare nanoprotein particles carrying α-amylase ► Characterization of nanostructured α-amylase ► Usability of α-amylase nanoparticles in hydrolysis of starch

Polymeric amylase nanoparticles as a new semi-synthetic enzyme system for hydrolysis of starch

Energy Technology Data Exchange (ETDEWEB)

Say, R. [Anadolu University, Faculty of Science, Chemistry Department, Yunus Emre Campus, Eskişehir (Turkey); Şenay, R. Hilal [Ege University, Faculty of Science, Biochemistry Department, 35100 Bornova-Izmir (Turkey); Biçen, Özlem; Ersöz, Arzu; Şişman Yılmaz, Filiz [Anadolu University, Faculty of Science, Chemistry Department, Yunus Emre Campus, Eskişehir (Turkey); Akgöl, Sinan, E-mail: sinanakgol@yahoo.co.uk [Ege University, Faculty of Science, Biochemistry Department, 35100 Bornova-Izmir (Turkey); Denizli, Adil [Hacettepe University, Faculty of Science, Chemistry Department, 06532 Ankara (Turkey)

2013-05-01

α-Amylase (EC 3.2.1.1; α-D-1,4,glucan glucanohydrolase) catalyzes the hydrolysis of α-D-(1,4)-glucosidic linkages in starch, glycogen, and various malto-oligosaccharides, by releasing α-anomeric products. In this study, a novel method has been developed to prepare nanoprotein particles that carry α-amylase as a monomer by using a photosensitive microemulsion polymerization process. The nanostructured α-amylase with photosensitive features have been characterized by fluorescence spectroscopy, transmission electron microscopy (TEM) and Zeta Sizer. The fluorescence intensity of amylase nanoparticles was determined to be 658 a.u. at 610 nm and the average particle size of nanoamylase was found to be about 71.8 nm. Both free α-amylase and nanoparticles were used in the hydrolysis of starch under varying reaction conditions such as pH and temperature that affect enzyme activity and the results were compared to each other. K{sub m} values were 0.26 and 0.87 mM and V{sub max} values were 0.36 IU mg{sup −1} and 22.32 IU mg{sup −1} for nanoenzyme and free enzyme, respectively. Then, thermal stability, storage stability and reusability were investigated and according to the results, activity was preserved 60% at 60 °C; 20% at 70–80 °C temperature values and 80% after 105 days storage. Finally after 10 cycles, the activity was preserved 90% and this novel enzymatic polymeric amylase nanoparticle has showed considerable potential as reusable catalyst. - Highlights: ► Developing to prepare nanoprotein particles carrying α-amylase ► Characterization of nanostructured α-amylase ► Usability of α-amylase nanoparticles in hydrolysis of starch.

The Importance of Surface-Binding Site towards Starch-Adsorptivity Level in α-Amylase: A Review on Structural Point of View

Directory of Open Access Journals (Sweden)

Umi Baroroh

2017-01-01

Full Text Available Starch is a polymeric carbohydrate composed of glucose. As a source of energy, starch can be degraded by various amylolytic enzymes, including α-amylase. In a large-scale industry, starch processing cost is still expensive due to the requirement of high temperature during the gelatinization step. Therefore, α-amylase with raw starch digesting ability could decrease the energy cost by avoiding the high gelatinization temperature. It is known that the carbohydrate-binding module (CBM and the surface-binding site (SBS of α-amylase could facilitate the substrate binding to the enzyme’s active site to enhance the starch digestion. These sites are a noncatalytic module, which could interact with a lengthy substrate such as insoluble starch. The major interaction between these sites and the substrate is the CH/pi-stacking interaction with the glucose ring. Several mutation studies on the Halothermothrix orenii, SusG Bacteroides thetaiotamicron, Barley, Aspergillus niger, and Saccharomycopsis fibuligera α-amylases have revealed that the stacking interaction through the aromatic residues at the SBS is essential to the starch adsorption. In this review, the SBS in various α-amylases is also presented. Therefore, based on the structural point of view, SBS is suggested as an essential site in α-amylase to increase its catalytic activity, especially towards the insoluble starch.

Impact of Dietary Resistant Starch on the Human Gut Microbiome, Metaproteome, and Metabolome.

Science.gov (United States)

Maier, Tanja V; Lucio, Marianna; Lee, Lang Ho; VerBerkmoes, Nathan C; Brislawn, Colin J; Bernhardt, Jörg; Lamendella, Regina; McDermott, Jason E; Bergeron, Nathalie; Heinzmann, Silke S; Morton, James T; González, Antonio; Ackermann, Gail; Knight, Rob; Riedel, Katharina; Krauss, Ronald M; Schmitt-Kopplin, Philippe; Jansson, Janet K

2017-10-17

Diet can influence the composition of the human microbiome, and yet relatively few dietary ingredients have been systematically investigated with respect to their impact on the functional potential of the microbiome. Dietary resistant starch (RS) has been shown to have health benefits, but we lack a mechanistic understanding of the metabolic processes that occur in the gut during digestion of RS. Here, we collected samples during a dietary crossover study with diets containing large or small amounts of RS. We determined the impact of RS on the gut microbiome and metabolic pathways in the gut, using a combination of "omics" approaches, including 16S rRNA gene sequencing, metaproteomics, and metabolomics. This multiomics approach captured changes in the abundance of specific bacterial species, proteins, and metabolites after a diet high in resistant starch (HRS), providing key insights into the influence of dietary interventions on the gut microbiome. The combined data showed that a high-RS diet caused an increase in the ratio of Firmicutes to Bacteroidetes , including increases in relative abundances of some specific members of the Firmicutes and concurrent increases in enzymatic pathways and metabolites involved in lipid metabolism in the gut. IMPORTANCE This work was undertaken to obtain a mechanistic understanding of the complex interplay between diet and the microorganisms residing in the intestine. Although it is known that gut microbes play a key role in digestion of the food that we consume, the specific contributions of different microorganisms are not well understood. In addition, the metabolic pathways and resultant products of metabolism during digestion are highly complex. To address these knowledge gaps, we used a combination of molecular approaches to determine the identities of the microorganisms in the gut during digestion of dietary starch as well as the metabolic pathways that they carry out. Together, these data provide a more complete picture of

Impact of Dietary Resistant Starch on the Human Gut Microbiome, Metaproteome, and Metabolome

Energy Technology Data Exchange (ETDEWEB)

Maier, Tanja V.; Lucio, Marianna; Lee, Lang Ho; VerBerkmoes, Nathan C.; Brislawn, Colin J.; Bernhardt, Jörg; Lamendella, Regina; McDermott, Jason E.; Bergeron, Nathalie; Heinzmann, Silke S.; Morton, James T.; González, Antonio; Ackermann, Gail; Knight, Rob; Riedel, Katharina; Krauss, Ronald M.; Schmitt-Kopplin, Philippe; Jansson, Janet K.; Moran, Mary Ann

2017-10-17

Diet can influence the composition of the human microbiome, and yet relatively few dietary ingredients have been systematically investigated with respect to their impact on the functional potential of the microbiome. Dietary resistant starch (RS) has been shown to have health benefits, but we lack a mechanistic understanding of the metabolic processes that occur in the gut during digestion of RS. Here, we collected samples during a dietary crossover study with diets containing large or small amounts of RS. We determined the impact of RS on the gut microbiome and metabolic pathways in the gut, using a combination of “omics” approaches, including 16S rRNA gene sequencing, metaproteomics, and metabolomics. This multiomics approach captured changes in the abundance of specific bacterial species, proteins, and metabolites after a diet high in resistant starch (HRS), providing key insights into the influence of dietary interventions on the gut microbiome. The combined data showed that a high-RS diet caused an increase in the ratio ofFirmicutestoBacteroidetes, including increases in relative abundances of some specific members of theFirmicutesand concurrent increases in enzymatic pathways and metabolites involved in lipid metabolism in the gut.

IMPORTANCEThis work was undertaken to obtain a mechanistic understanding of the complex interplay between diet and the microorganisms residing in the intestine. Although it is known that gut microbes play a key role in digestion of the food that we consume, the specific contributions of different microorganisms are not well understood. In addition, the metabolic pathways and resultant products of metabolism during digestion are highly complex. To address these knowledge gaps, we used a combination of molecular approaches to determine the identities of the microorganisms in the gut during digestion of dietary starch as well as the

Analysis of a preferential action of α-amylase from B. licheniformis towards amorphous regions of waxy maize starch.

Science.gov (United States)

Foresti, María Laura; Williams, María del Pilar; Martínez-García, Ricardo; Vázquez, Analía

2014-02-15

Waxy maize starch was subjected to α-amylase (Bacillus licheniformis) hydrolysis in buffered medium to determine the evolution of reaction in quantitative terms and also in terms of the morphology and crystallinity of the partially hydrolyzed starch granules. Gathered data allowed studying the pattern of action of this α-amylase over waxy maize starch granules, with particular focus on a preferential hydrolysis of the amorphous regions of starch. Results showed that waxy maize starch hydrolysis followed a two-stage kinetic profile with an initial stage characterized by high reaction rate, followed by a slower second stage. The change of hydrolysis rate occurred at approximately 6h of reaction, a time for which X-ray diffraction data quantitatively analyzed by three different techniques showed a maximum of crystallinity in partially hydrolyzed granules. Scanning electron microscopy images illustrated the action of α-amylases which implied the exoerosion of the granules surface, the entry of α-amylases into the granules through radial channels, their endoerosion towards the granule exterior, and their fragmentation. Fragmentation of waxy maize starch granules revealed internal layered structures of starch which were interpreted as hydrolyzed/non-hydrolyzed growth rings. Under the conditions chosen, kinetic, electron microscopy and X-ray data all gave evidence of a preferential action of α-amylase from Bacillus licheniformis towards the less ordered regions of waxy maize starch. Results showed that, provided the proper hydrolysis time is chosen, starch granules with increased crystallinity can be obtained by a pure enzymatic treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

α--AMYLASES OF Aspergillus flavus var. oryzae AND Bacillus subtilis: THE SUBSTRATE SPECIFICITY AND RESISTANCE TO A NUMBER OF CHEMICALLY ACTIVE SUBSTANCES

Directory of Open Access Journals (Sweden)

K. V. Avdiyuk

2013-06-01

Full Text Available The ability of Aspergillus flavus var. oryzae 80428 and Bacillus subtilis 147 α-amylases to split different carbohydrate-containing substrates, such as maltose, sucrose, trehalose, dextrin, α- and β-cyclodextrin, amylose, amylopectin, glycogen, pullulan, soluble starch, insoluble starch, corn starch, wheat starch, dextran 500 has been studied. It was shown that investigated enzymes differ by substrate specificity. α-Amylase of A. flavus var. oryzae 80428 rapidly hydrolysed soluble potato and wheat starch, while the α-amylase of B. subtilis 147 — only wheat starch. Both enzymes don’t cleave maltose, α-cyclodextrin and dextran 500. A. flavus var. oryzae 80428 α-amylase display very small ability to hydrolyze pullulan, while α-amylase of B. subtilis 147 it does not act in general. The lowest values of Michaelis constant for both enzymes at splitting of glycogen have been obtained, indicating that enzymes have the greatest affinity to this substrate. The studies of influence of chemically active substances on activity of A. flavus var. oryzae 80428 and B. subtilis 147 ?-amylases show there are resistant to urea, deoxycholic acid, Tween-80, Triton X-100 and hydrogen peroxide. It’s indicate the enzymes tested may be competitive in compare with earlier described in literature enzymes. The obtained results give a possibility to propose in future usage these enzymes in different fields of industry, foremost in detergent industry.

Digestion and Interaction of Starches with α-Amylases: I. Mutational analysis of Carbohydrate Binding Sites in barley. II. In Vitro Starch Digestion of Legumes

DEFF Research Database (Denmark)

Nielsen, Morten Munch

2006-01-01

the hydrolysis of internal 1,4-α-D-glucosidic bonds in starch and related polysaccharides. The present thesis concerns studies of two α-amylases: 1) secondary substrate binding sites in barley α-amylase 1 (AMY1), and 2) the involvement of anti-nutrients in in vitro digestion of starch in legumes by porcine...... in morphology between high amylose starch granules and normal starch granules. Legumes (beans, peas, and lentils) are characterised by low blood glucose raising potential, which is proportional to the in vitro starch digestion rates. The high amount of anti-nutritional factors (phytate, proteinaceous inhibitors......, tannins, and lectins) in legumes has been associated with the slow starch digestion. However, it is still debated in literature to which extent the legume starch digestibility is affected by anti-nutritional factors. The in vitro starch digestion (hydrolytic index, HI) of pea (Pisum sativum) and mixtures...

Effect of α-Amylase Degradation on Physicochemical Properties of Pre-High Hydrostatic Pressure-Treated Potato Starch

Science.gov (United States)

Mu, Tai-Hua; Zhang, Miao; Raad, Leyla; Sun, Hong-Nan; Wang, Cheng

2015-01-01

The effect of high hydrostatic pressure (HHP) on the susceptibility of potato starch (25%, w/v) suspended in water to degradation by exposure to bacterial α-amylase (0.02%, 0.04% and 0.06%, w/v) for 40 min at 25°C was investigated. Significant differences (p starch (PS) exposed to α-amylase (0.06%, w/v) showed a significantly greater degree of hydrolysis and amount of reducing sugar released compared to α-amylase at a concentration of 0.04% (w/v) or 0.02% (w/v). Native PS (NPS) granules have a spherical and elliptical form with a smooth surface, whereas the hydrolyzed NPS (hNPS) and hydrolyzed HHP-treated PS granules showed irregular and ruptured forms with several cracks and holes on the surface. Hydrolysis of HHP-treated PS by α-amylase could decrease the average granule size significantly (p starch in both the ordered and the amorphous structure, especially in hydrolyzed HHP600 PS. The B-type of hydrolyzed HHP600 PS with α-amylase at a concentration 0.06% (w/v) changed to a B+V type with an additional peak at 2θ = 19.36°. The HHP600 starch with 0.06% (w/v) α-amylase displayed the lowest value of T o (onset temperature), T c (conclusion temperature) and ΔH gel (enthalpies of gelatinization). These results indicate the pre-HHP treatment of NPS leads to increased susceptibility of the granules to enzymatic degradation and eventually changes of both the amorphous and the crystalline structures. PMID:26642044

The important role of salivary α-amylase in the gastric digestion of wheat bread starch.

Science.gov (United States)

Freitas, Daniela; Le Feunteun, Steven; Panouillé, Maud; Souchon, Isabelle

2018-01-24

The role of salivary α-amylase (HSA) in starch digestion is often overlooked in favour of that of pancreatic α-amylase due to the short duration of the oral phase. Although it is generally accepted that the amylase of salivary origin can continue to be active in the stomach, studies ascertaining its contribution are lacking. This study aimed to address this issue by coupling in vitro oral processing with an in vitro dynamic system that mimicked different postprandial gastric pH reduction kinetics observed in vivo following a snack- or lunch-type meal. The digestion of both starch and protein from wheat bread as well as the interplay between the two processes were studied. We have observed that the amylolytic activity of saliva plays a preponderant role hydrolysing up to 80% of bread starch in the first 30 min of gastric digestion. Amylolysis evolved exponentially and nearly superimposing curves were obtained regardless of the acidification profiles, revealing its high efficiency.

Partial purification and characterization of α-amylases from one insecticide-resistant population of Sitophilus zeamais

International Nuclear Information System (INIS)

Lopes, K.V.; Oliveira, M.G.A.; Paixao, G.P.; Visotto, L.E.; Veloso, R.V.S.; Marinho, J.S.; Guedes, R.N.C.; Oliveira, J.A.

2008-01-01

Full text: α-Amylases (EC 3.2.1.1) constitute a family of endo-amylases that catalyze the hydrolysis of a-D- (1,4)-glucan linkages in st ach components and various other related carbohydrates. They play a central role in carbohydrate metabolism of animals, plants and microorganisms. Many insects, especially those that feed on grain products during larval and/or adult life, depend on their amylases for survival. This is particularly true for the Sitophilus zeamais Motschulsky, a cosmopolitan pest of stored products. It is mainly controlled by insecticides. Amylases from adults of S.zeamais insecticide-resistant were purified by using a sequential procedure of glycogen-complex precipitation and ion exchange chromatography. Specific activity increased from 58,0454 AU/dL/mg protein in the crude homogenate to 2558,8720 AU/dL/mg protein in the final purified sample. Amylase unit (AU/dL) refers to the amount of amylase that hydrolysis 10 mg starch in 30 min at 37 deg C. The purified amylase ran as a single protein band on SDS-PAGE. From a plot of log molecular weight against relative mobility in 10% acrylamide gel, molecular weight was estimated to be 56 kDa. The enzyme had a K m of 0,2243 g/L for soluble starch and was most active at ph 5,0. The temperature of major activity was 40 deg C. The activity of enzyme was unaffected by presence or absence of Cl - and Ca 2+

SusG: A Unique Cell-Membrane-Associated [alpha]-Amylase from a Prominent Human Gut Symbiont Targets Complex Starch Molecules

Energy Technology Data Exchange (ETDEWEB)

Koropatkin, Nicole M.; Smith, Thomas J. (Danforth)

2010-09-21

SusG is an {alpha}-amylase and part of a large protein complex on the outer surface of the bacterial cell and plays a major role in carbohydrate acquisition by the animal gut microbiota. Presented here, the atomic structure of SusG has an unusual extended, bilobed structure composed of amylase at one end and an unprecedented internal carbohydrate-binding motif at the other. Structural studies further demonstrate that the carbohydrate-binding motif binds maltooligosaccharide distal to, and on the opposite side of, the amylase catalytic site. SusG has an additional starch-binding site on the amylase domain immediately adjacent to the active cleft. Mutagenesis analysis demonstrates that these two additional starch-binding sites appear to play a role in catabolism of insoluble starch. However, elimination of these sites has only a limited effect, suggesting that they may have a more important role in product exchange with other Sus components.

Utilization of α-amylase enzyme from Bacillus stearothermophilus RSAII1B for maltodextrin production from sago starch

Science.gov (United States)

Arfah, R. A.; Ahmad, A.; Dali, S.; Djide, M. N.; Mahdalia; Arif, A. R.

2018-03-01

The dried sago flour derived from Palopo contains 28.80% amylose and 91.23% total carbohydrate. Based on the data, sago starch has the potential to become an alternative raw material for themaltodextrin production. Maltodextrin is one of the starch derivative products produced by hydrolysis process using the α-amylase enzyme with amaximum DE (dextrose equivalent) value of 20. The use of maltodextrin for food and pharmaceutical industries is increasing because of maltodextrin is widely used as thickener filler, surfactant and sugar substitute in milk powder. The aims of this study are to optimize the addition of enzyme concentration and hydrolysis time of α -amylase enzyme to obtain high quality ofmaltodextrin This study also aimed to characterization the obtained maltodextrin. The first step was isolation and purification α-amylase from the isolate of Bacillus stearothermophilus RSAII1B, followed by determination of the α-amylase concentration (0.05%, 0.07% and 0.09%) in 2.0% starch substrate, and the hydrolysis time ofα-amilase (60, 90, 120, 240 minutes). Maltodextrin characters observed were dextrose equivalent (DE), reducing sugar, moisture content, pH changes, color, solubility, viscosity, and total plate count (TPC). The results showed that the value of DE was 12.31, reducing sugar was 11.4%; water content was 10.92%; pH was 4.85; The color of maltodextrin powder was white bone color; solubility was 153.2 g/L; Viscositywas 210-240 cps, TPCwas 380 cfu/g. Maltodextrins produced from sago starch using the α-amylase enzyme from B.stearothermophillus RSAIIm met the quality requirements of SNI 7599: 2010.

Partial purification and characterization of {alpha}-amylases from one insecticide-resistant population of Sitophilus zeamais

Energy Technology Data Exchange (ETDEWEB)

Lopes, K.V.; Oliveira, M.G.A.; Paixao, G.P.; Visotto, L.E. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Bioquimica e Biologia Molecular; Veloso, R.V.S.; Marinho, J.S.; Guedes, R.N.C. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Biologia Animal; Oliveira, J.A. [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Quimica

2008-07-01

Full text: {alpha}-Amylases (EC 3.2.1.1) constitute a family of endo-amylases that catalyze the hydrolysis of a-D- (1,4)-glucan linkages in st ach components and various other related carbohydrates. They play a central role in carbohydrate metabolism of animals, plants and microorganisms. Many insects, especially those that feed on grain products during larval and/or adult life, depend on their amylases for survival. This is particularly true for the Sitophilus zeamais Motschulsky, a cosmopolitan pest of stored products. It is mainly controlled by insecticides. Amylases from adults of S.zeamais insecticide-resistant were purified by using a sequential procedure of glycogen-complex precipitation and ion exchange chromatography. Specific activity increased from 58,0454 AU/dL/mg protein in the crude homogenate to 2558,8720 AU/dL/mg protein in the final purified sample. Amylase unit (AU/dL) refers to the amount of amylase that hydrolysis 10 mg starch in 30 min at 37 deg C. The purified amylase ran as a single protein band on SDS-PAGE. From a plot of log molecular weight against relative mobility in 10% acrylamide gel, molecular weight was estimated to be 56 kDa. The enzyme had a K{sub m} of 0,2243 g/L for soluble starch and was most active at ph 5,0. The temperature of major activity was 40 deg C. The activity of enzyme was unaffected by presence or absence of Cl{sup -} and Ca{sup 2+}.

Effect of gelatinization and hydrolysis conditions on the selectivity of starch hydrolysis with alpha-amylase from Bacillus licheniformis

NARCIS (Netherlands)

Baks, T.; Bruins, M.E.; Matser, A.M.; Janssen, A.E.M.; Boom, R.M.

2008-01-01

Enzymatic hydrolysis of starch can be used to obtain various valuable hydrolyzates with different compositions. The effects of starch pretreatment, enzyme addition point, and hydrolysis conditions on the hydrolyzate composition and reaction rate during wheat starch hydrolysis with ¿-amylase from

Polymeric amylase nanoparticles as a new semi-synthetic enzyme system for hydrolysis of starch.

Science.gov (United States)

Say, R; Şenay, R Hilal; Biçen, Özlem; Ersöz, Arzu; Şişman Yılmaz, Filiz; Akgöl, Sinan; Denizli, Adil

2013-05-01

α-Amylase (EC 3.2.1.1; α-D-1,4,glucan glucanohydrolase) catalyzes the hydrolysis of α-D-(1,4)-glucosidic linkages in starch, glycogen, and various malto-oligosaccharides, by releasing α-anomeric products. In this study, a novel method has been developed to prepare nanoprotein particles that carry α-amylase as a monomer by using a photosensitive microemulsion polymerization process. The nanostructured α-amylase with photosensitive features have been characterized by fluorescence spectroscopy, transmission electron microscopy (TEM) and Zeta Sizer. The fluorescence intensity of amylase nanoparticles was determined to be 658 a.u. at 610 nm and the average particle size of nanoamylase was found to be about 71.8 nm. Both free α-amylase and nanoparticles were used in the hydrolysis of starch under varying reaction conditions such as pH and temperature that affect enzyme activity and the results were compared to each other. Km values were 0.26 and 0.87 mM and Vmax values were 0.36 IU mg(-1) and 22.32 IU mg(-1) for nanoenzyme and free enzyme, respectively. Then, thermal stability, storage stability and reusability were investigated and according to the results, activity was preserved 60% at 60 °C; 20% at 70-80 °C temperature values and 80% after 105 days storage. Finally after 10 cycles, the activity was preserved 90% and this novel enzymatic polymeric amylase nanoparticle has showed considerable potential as reusable catalyst. Copyright © 2012 Elsevier B.V. All rights reserved.

Overcoming hydrolysis of raw corn starch under industrial conditions with Bacillus licheniformis ATCC 9945a α-amylase.

Science.gov (United States)

Šokarda Slavić, Marinela; Pešić, Milja; Vujčić, Zoran; Božić, Nataša

2016-03-01

α-Amylase from Bacillus licheniformis ATCC 9945a (BliAmy) was proven to be very efficient in hydrolysis of granular starch below the temperature of gelatinization. By applying two-stage feeding strategy to achieve high-cell-density cultivation of Escherichia coli and extracellular production of BliAmy, total of 250.5 U/mL (i.e. 0.7 g/L) of enzyme was obtained. Thermostability of amylase was exploited to simplify purification. The hydrolysis of concentrated raw starch was optimized using response surface methodology. Regardless of raw starch concentration tested (20, 25, 30 %), BliAmy was very effective, achieving the final hydrolysis degree of 91 % for the hydrolysis of 30 % starch suspension after 24 h. The major A-type crystalline structure and amorphous domains of the starch granule were degraded at the same rates, while amylose-lipid complexes were not degraded. BliAmy presents interesting performances on highly concentrated solid starch and could be of value for starch-consuming industries while response surface methodology (RSM) could be efficiently applied for the optimization of the hydrolysis.

Use of enzymes to minimize the rheological dough problems caused by high levels of damaged starch in starch-gluten systems.

Science.gov (United States)

Barrera, Gabriela N; León, Alberto E; Ribotta, Pablo D

2016-05-01

During wheat milling, starch granules can experience mechanical damage, producing damaged starch. High levels of damaged starch modify the physicochemical properties of wheat flour, negatively affecting the dough behavior as well as the flour quality and cookie and bread making quality. The aim of this work was to evaluate the effect of α-amylase, maltogenic amylase and amyloglucosidase on dough rheology in order to propose alternatives to reduce the issues related to high levels of damaged starch. The dough with a high level of damaged starch became more viscous and resistant to deformations as well as less elastic and extensible. The soluble fraction of the doughs influenced the rheological behavior of the systems. The α-amylase and amyloglucosidase reduced the negative effects of high damaged starch contents, improving the dough rheological properties modified by damaged starch. The rheological behavior of dough with the higher damaged-starch content was related to a more open gluten network arrangement as a result of the large size of the swollen damaged starch granules. We can conclude that the dough rheological properties of systems with high damaged starch content changed positively as a result of enzyme action, particularly α-amylase and amyloglucosidase additions, allowing the use of these amylases and mixtures of them as corrective additives. Little information was reported about amyloglucosidase activity alone or combined with α-amylase. The combinations of these two enzymes are promising to minimize the negative effects caused by high levels of damaged starch on product quality. More research needs to be done on bread quality combining these two enzymes. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Effect of the glass transition temperature on alpha-amylase activity in a starch matrix.

Science.gov (United States)

Chaudhary, Vinita; Panyoyai, Naksit; Small, Darryl M; Shanks, Robert A; Kasapis, Stefan

2017-02-10

This study optimises a protocol for the estimation of α-amylase activity in a condensed starch matrix in the vicinity of the glass transition region. Enzymatic activity on the vitrified starch system was compared with that of a reference substrate, maltodextrin. The activity was assayed as the rate of release of reducing sugar using a dinitrosalicylic acid procedure. The condensed carbohydrate matrices served the dual purpose of acting as a substrate as well as producing a pronounced effect on the ability to enzymatic hydrolysis. Activation energies were estimated throughout the glass transition region of condensed carbohydrate preparations based on the concept of the spectroscopic shift factor. Results were used to demonstrate a considerable moderation by the mechanical glass transition temperature, beyond the expected linear effect of the temperature dependence, on the reaction rate of starch hydrolysis by α-amylase in comparison with the low-molecular weight chain of maltodextrin. Copyright © 2016. Published by Elsevier Ltd.

Chloride Activated Halophilic α-Amylase from Marinobacter sp. EMB8: Production Optimization and Nanoimmobilization for Efficient Starch Hydrolysis

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Sumit Kumar

2015-01-01

Full Text Available Halophiles have been perceived as potential source of novel enzymes in recent years. The interest emanates from their ability to catalyze efficiently under high salt and organic solvents. Present work encompasses production optimization and nanoimmobilization of an α-amylase from moderately halophilic Marinobacter sp. EMB8. Media ingredients and culture conditions were optimized by “one-at-a-time approach.” Starch was found to be the best carbon source at 5% (w/v concentration. Glucose acted as catabolic repressor for amylase production. Salt proved critical for amylase production and maximum production was attained at 5% (w/v NaCl. Optimization of various culture parameters resulted in 48.0 IU/mL amylase production, a 12-fold increase over that of unoptimized condition (4.0 IU/mL. α-Amylase was immobilized on 3-aminopropyl functionalized silica nanoparticles using glutaraldehyde as cross-linking agent. Optimization of various parameters resulted in 96% immobilization efficiency. Starch hydrolyzing efficiency of immobilized enzyme was comparatively better. Immobilized α-amylase retained 75% of its activity after 5th cycle of repeated use.

Effect of feeding a reduced-starch diet with or without amylase addition on lactation performance in dairy cows

NARCIS (Netherlands)

Gencoglu, H.; Shaver, R.D.; Steinberg, W.; Ensink, J.; Ferraretto, L.F.; Bertics, S.J.; Lopes, J.C.; Akins, M.S.

2010-01-01

The objective of this study was to determine lactation performance responses of high-producing dairy cows to a reduced-starch diet compared with a normal-starch diet and to the addition of exogenous amylase to the reduced-starch diet. Thirty-six multiparous Holstein cows (51 +/- 22 DIM and 643 +/-

Impact of α-amylase during breadmaking on in vitro kinetics of starch hydrolysis and glycaemic index of enriched bread with bran.

Science.gov (United States)

Sanz-Penella, Juan Mario; Laparra, José Moisés; Haros, Monika

2014-09-01

Nowadays, the use of enzymes has become a common practice in the bakery industry, as they can improve dough quality and texture of final product. However, the use of α-amylases could have a negative effect in the glycaemic load of product, due to the released sugars from the starch hydrolysis that are not used by yeasts during the fermentation process. This study evaluated the effect of the addition of α-amylase in bakery products with bran on in vitro kinetics of starch hydrolysis. The use of flour with a high degree of extraction or high bran amount could decrease the GI even with the inclusion of α-amylase in the formulation. It should be taken into account the amount of bran and α-amylase when formulating breads in order to obtain products with lower GI than white bread. However, the fact that kinetics of starch hydrolysis remained unaltered indicates that the use of α-amylase in bread-making processes could provide technological advantages improving quality of breads without markedly changes in their glycaemic index.

Utilization of corn starch as sustrate for ß-Amylase by Bacillus SPP

African Journals Online (AJOL)

Corn starch was used as substrate for ß -amylase production from ten(10) amylolytic species of the genus Bacillus isolated locally from soil, waste water and food sources. Ten bacillus strains was made up of two strains each of Bacillus macerans, Bacillus licheniformis and Bacillus circulans. Also included are B. coagulans, ...

A starch-binding domain identified in α-amylase (AmyP) represents a new family of carbohydrate-binding modules that contribute to enzymatic hydrolysis of soluble starch.

Science.gov (United States)

Peng, Hui; Zheng, Yunyun; Chen, Maojiao; Wang, Ying; Xiao, Yazhong; Gao, Yi

2014-04-02

A novel starch-binding domain (SBD) that represents a new carbohydrate-binding module family (CBM69) was identified in the α-amylase (AmyP) of the recently established alpha-amylase subfamily GH13_37. The SBD and its homologues come mostly from marine bacteria, and phylogenetic analysis indicates that they are closely related to the CBM20 and CBM48 families. The SBD exhibited a binding preference toward raw rice starch, but the truncated mutant (AmyPΔSBD) still retained similar substrate preference. Kinetic analyses revealed that the SBD plays an important role in soluble starch hydrolysis because different catalytic efficiencies have been observed in AmyP and the AmyPΔSBD. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Glucan, Water Dikinase Activity Stimulates Breakdown of Starch Granules by Plastidial β-Amylases1[W][OA

Science.gov (United States)

Edner, Christoph; Li, Jing; Albrecht, Tanja; Mahlow, Sebastian; Hejazi, Mahdi; Hussain, Hasnain; Kaplan, Fatma; Guy, Charles; Smith, Steven M.; Steup, Martin; Ritte, Gerhard

2007-01-01

Glucan phosphorylating enzymes are required for normal mobilization of starch in leaves of Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum), but mechanisms underlying this dependency are unknown. Using two different activity assays, we aimed to identify starch degrading enzymes from Arabidopsis, whose activity is affected by glucan phosphorylation. Breakdown of granular starch by a protein fraction purified from leaf extracts increased approximately 2-fold if the granules were simultaneously phosphorylated by recombinant potato glucan, water dikinase (GWD). Using matrix-assisted laser-desorption ionization mass spectrometry several putative starch-related enzymes were identified in this fraction, among them β-AMYLASE1 (BAM1; At3g23920) and ISOAMYLASE3 (ISA3; At4g09020). Experiments using purified recombinant enzymes showed that BAM1 activity with granules similarly increased under conditions of simultaneous starch phosphorylation. Purified recombinant potato ISA3 (StISA3) did not attack the granular starch significantly with or without glucan phosphorylation. However, starch breakdown by a mixture of BAM1 and StISA3 was 2 times higher than that by BAM1 alone and was further enhanced in the presence of GWD and ATP. Similar to BAM1, maltose release from granular starch by purified recombinant BAM3 (At4g17090), another plastid-localized β-amylase isoform, increased 2- to 3-fold if the granules were simultaneously phosphorylated by GWD. BAM activity in turn strongly stimulated the GWD-catalyzed phosphorylation. The interdependence between the activities of GWD and BAMs offers an explanation for the severe starch excess phenotype of GWD-deficient mutants. PMID:17631522

Low frequency ultrasonic-assisted hydrolysis of starch in the presence of α-amylase.

Science.gov (United States)

Gaquere-Parker, Anne; Taylor, Tamera; Hutson, Raihannah; Rizzo, Ashley; Folds, Aubrey; Crittenden, Shastina; Zahoor, Neelam; Hussein, Bilal; Arruda, Aaron

2018-03-01

Hydrolysis of starch is an important process in the food industry and in the production of bioethanol or smaller carbohydrate molecules that can be used as starting blocks for chemical synthesis. Such hydrolysis can be enhanced by lowering the pH, heating the reaction mixture or catalyzing the reaction with enzymes. This study reports the effect of sonication on the reaction rate of starch hydrolysis at different temperatures, in the presence or absence of alpha-amylase. Starch Azure, a commercially available potato starch covalently linked with Remazol Brilliant Blue, has been chosen since its hydrolysis releases a blue dye, which concentration can be monitored by UV Vis spectroscopy. Ultrasounds, regardless of experimental conditions, provide the highest reaction rate for such hydrolysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Maltose Production Using Starch from Cassava Bagasse Catalyzed by Cross-Linked β-Amylase Aggregates

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Rafael Araujo-Silva

2018-04-01

Full Text Available Barley β-amylase was immobilized using different techniques. The highest global yield was obtained using the cross-linked enzyme aggregates (CLEA technique, employing bovine serum albumin (BSA or soy protein isolate (SPI as feeder proteins to reduce diffusion problems. The CLEAs produced using BSA or SPI showed 82.7 ± 5.8 and 53.3 ± 2.4% global yield, respectively, and a stabilization effect was observed upon immobilization at neutral pH value, e.g., after 12 h at 55 °C, the free β-amylase is fully inactivated, while CLEAs retained 25 and 15% of activity (using BSA and SPI, respectively. CLEA using SPI was selected because of its easier recovery, being chosen to convert the residual starch contained in cassava bagasse into maltose. This biocatalyst permitted to reach almost 70% of maltose conversion in 4 h using 30.0 g/L bagasse starch solution (Dextrose Equivalent of 15.88 and 1.2 U of biocatalyst per gram of starch at pH 7.0 and 40 °C. After 4 reuses (batches of 12 h the CLEA using SPI maintained 25.50 ± 0.01% of conversion due to the difficulty of recovering.

Intactness of cell wall structure controls the in vitro digestion of starch in legumes.

Science.gov (United States)

Dhital, Sushil; Bhattarai, Rewati R; Gorham, John; Gidley, Michael J

2016-03-01

Increasing the level of starch that is not digested by the end of the small intestine and therefore enters the colon ('resistant starch') is a major opportunity for improving the nutritional profile of foods. One mechanism that has been shown to be successful is entrapment of starch within an intact plant tissue structure. However, the level of tissue intactness required for resistance to amylase digestion has not been defined. In this study, intact cells were isolated from a range of legumes after thermal treatment at 60 °C (starch not gelatinised) or 95 °C (starch gelatinised) followed by hydrolysis using pancreatic alpha amylase. It was found that intact cells, isolated at either temperature, were impervious to amylase. However, application of mechanical force damaged the cell wall and made starch accessible to digestive enzymes. This shows that the access of enzymes to the entrapped swollen starch is the rate limiting step controlling hydrolysis of starch in cooked legumes. The results suggest that a single cell wall could be sufficient to provide an effective delivery of starch to the large intestine with consequent nutritional benefits, provided that mechanical damage during digestion is avoided.

Statistically designed optimisation of enzyme catalysed starch removal from potato pulp

DEFF Research Database (Denmark)

Thomassen, Lise Vestergaard; Meyer, Anne S.

2010-01-01

to obtain dietary fibers is usually accomplished via a three step, sequential enzymatic treatment procedure using a heat stable alpha-amylase, protease, and amyloglucosidase. Statistically designed experiments were performed to investigate the influence of enzyme dose, amount of dry matter, incubation time...... and temperature on the amount of starch released from the potato pulp. The data demonstrated that all the starch could be released from potato pulp in one step when 8% (w/w) dry potato pulp was treated with 0.2% (v/w) (enzyme/substrate (E/S)) of a thermostable Bacillus licheniformis alpha-amylase (Termamyl(R) SC...

Resistant starch in cassava products

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Bruna Letícia Buzati Pereira

2014-06-01

Full Text Available 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 analyzed. The method used for determination of resistant starch consisted of an enzymatic process to calculate the final content of resistant starch considering the concentration of glucose released and analyzed. The results showed significant differences between the products. Among the flours and seasoned flours analyzed, the highest levels of resistant starch were observed in the flour from Bahia state (2.21% and the seasoned flour from Paraná state (1.93%. Starch, tapioca, and sago showed levels of resistant starch ranging from 0.56 to 1.1%. The cassava products analyzed can be considered good sources of resistant starch; which make them beneficial products to the gastrointestinal tract.

Zinc oxide nanoparticles as novel alpha-amylase inhibitors

Science.gov (United States)

Dhobale, Sandip; Thite, Trupti; Laware, S. L.; Rode, C. V.; Koppikar, Soumya J.; Ghanekar, Ruchika-Kaul; Kale, S. N.

2008-11-01

Amylase inhibitors, also known as starch blockers, contain substances that prevent dietary starches from being absorbed by the body via inhibiting breakdown of complex sugars to simpler ones. In this sense, these materials are projected as having potential applications in diabetes control. In this context, we report on zinc oxide nanoparticles as possible alpha-amylase inhibitors. Zinc oxide nanoparticles have been synthesized using soft-chemistry approach and 1-thioglycerol was used as a surfactant to yield polycrystalline nanoparticles of size ˜18 nm, stabilized in wurtzite structure. Conjugation study and structural characterization have been done using x-ray diffraction technique, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and transmission electron microscopy. Cytotoxicity studies on human fibrosarcoma (HT-1080) and skin carcinoma (A-431) cell lines as well as mouse primary fibroblast cells demonstrate that up to a dose of 20 μg/ml, ZnO nanoparticles are nontoxic to the cells. We report for the first time the alpha-amylase inhibitory activity of ZnO nanoparticles wherein an optimum dose of 20 μg/ml was sufficient to exhibit 49% glucose inhibition at neutral pH and 35 °C temperature. This inhibitory activity was similar to that obtained with acarbose (a standard alpha-amylase inhibitor), thereby projecting ZnO nanoparticles as novel alpha-amylase inhibitors.

Effect of thermostable α-amylase injection on mechanical and physiochemical properties for saccharification of extruded corn starch.

Science.gov (United States)

Myat, Lin; Ryu, Gi-Hyung

2014-01-30

In industry, a jet cooker is used to gelatinize starch by mixing the starch slurry with steam under pressure at 100-175 °C. A higher degree of starch hydrolysis in an extruder is possible with glucoamylase. Unfortunately, it is difficult to carry out liquefaction and saccharification in parallel, because the temperature of gelatinization will be too high and will inactivate glucoamylase. Since the temperature for liquefaction and saccharification is different, it is hard to change the temperature from high (required for liquefaction) to low (required for saccharification). The industrial gelatinization process is usually carried out with 30-35% (w/w) dry solids starch slurry. Conventional jet cookers cannot be used any more at high substrate concentrations owing to higher viscosity. In this study, therefore, corn starch was extruded at different melt temperatures to overcome these limitations and to produce the highest enzyme-accessible starch extrudates. Significant effects on physical properties (water solubility index, water absorption index and color) and chemical properties (reducing sugar and % increase in reducing sugar after saccharification) were achieved by addition of thermostable α-amylase at melt temperatures of 115 and 135 °C. However, there was no significant effect on % increase in reducing sugar of extruded corn starch at 95 °C. The results show the great potential of extrusion with thermostable α-amylase injection at 115 and 135 °C as an effective pretreatment for breaking down starch granules, because of the significant increase (P < 0.05) in % reducing sugar and enzyme-accessible extrudates for saccharification yield. © 2013 Society of Chemical Industry.

Production of Active Bacillus licheniformis Alpha-Amylase in Tobacco and its Application in Starch Liquefaction

NARCIS (Netherlands)

Pen, J; MOLENDIJK, L; Quax, Wim J.; SIJMONS, PC; VANOOYEN, AJJ; VANDENELZEN, PJM; RIETVELD, K; HOEKEMA, A

As a first example of the feasibility of producing industrial bulk enzymes in plants, we have expressed Bacillus licheniformis alpha-amylase in transgenic tobacco, and applied the seeds directly in starch liquification. The enzyme was properly secreted into the intercellular space, and maximum

Amylase Zymography.

Science.gov (United States)

Andrades, Adarelys; Contreras, Lellys M

2017-01-01

Amylase zymography was carried out for the detection of amylases produced by a Geobacillus stearothermophilus strain isolated from the Thermal Center "Las Trincheras" in Venezuela. Zymography is an electrophoretic technique used to study hydrolases by means of thin gels containing copolymerized-specific substrates, under nonreducing conditions. In this study, 0.1% starch was incorporated into the gel as substrate. The formation of clear zones against a dark background in the gel stained with iodine indicated the presence of amylolytic activity. The thermophilic bacteria released several extracellular amylases to a selective growth medium supplemented with 1% soluble starch at 55 °C after 40 h incubation. The amylolytic enzymes showed an optimum temperature of 60 °C and an optimum pH at 6.0. The amylases were partially purified by cold acetone precipitation followed by two chromatographic techniques. These purified amylases showed different molecular masses which were determined by sodium dodecyl sulfate gel electrophoresis and confirmed by zymography.

Silver nanoparticles: a potential nanocatalyst for the rapid degradation of starch hydrolysis by α-amylase.

Science.gov (United States)

Ernest, Vinita; Shiny, P J; Mukherjee, Amitava; Chandrasekaran, N

2012-05-01

Silver nanoparticles (AgNPs) are proven to be an effective catalytic material for various applications due to their excellent optical and electronic properties. In this paper, we describe a novel approach for the degradation of starch using the catalytic behaviour of AgNPs in an enzyme catalysed reaction of starch hydrolysis by α-amylase. AgNPs were synthesized by soluble starch reducing silver nitrate to silver atoms. An increase of 4.7-fold in reducing sugar formation and 1.5 times faster enzyme activity confirmed the catalytic activity of AgNPs as a nanocatalyst. Surprisingly, starch degradation tests revealed that 9.9 mg of starch was hydrolysed within 5 min, which corroborates with the reducing sugar assay. In short, the present study paves way for the faster degradation of starch by immobilizing the enzyme onto the surface of the AgNP, which could be a promising application in the food industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

Solid State Fermentation of a Raw Starch Digesting Alkaline Alpha-Amylase from Bacillus licheniformis RT7PE1 and Its Characteristics.

Science.gov (United States)

Tabassum, Romana; Khaliq, Shazia; Rajoka, Muhammad Ibrahim; Agblevor, Foster

2014-01-01

The thermodynamic and kinetic properties of solids state raw starch digesting alpha amylase from newly isolated Bacillus licheniformis RT7PE1 strain were studied. The kinetic values Q p , Y p/s , Y p/X , and q p were proved to be best with 15% wheat bran. The molecular weight of purified enzyme was 112 kDa. The apparent K m and V max values for starch were 3.4 mg mL(-1) and 19.5 IU mg(-1) protein, respectively. The optimum temperature and pH for α -amylase were 55°C, 9.8. The half-life of enzyme at 95°C was 17h. The activation and denaturation activation energies were 45.2 and 41.2 kJ mol(-1), respectively. Both enthalpies (ΔH (∗)) and entropies of activation (ΔS (∗)) for denaturation of α -amylase were lower than those reported for other thermostable α -amylases.

Gamma irradiation of sorghum flour: Effects on microbial inactivation, amylase activity, fermentability, viscosity and starch granule structure

International Nuclear Information System (INIS)

Mukisa, Ivan M.; Muyanja, Charles M.B.K.; Byaruhanga, Yusuf B.; Schüller, Reidar B.; Langsrud, Thor; Narvhus, Judith A.

2012-01-01

Malted and un-malted sorghum (Sorghum bicolor (L.) Moench) flour was gamma irradiated with a dose of 10 kGy and then re-irradiated with 25 kGy. The effects of irradiation on microbial decontamination, amylase activity, fermentability (using an amylolytic L. plantarum MNC 21 strain), starch granule structure and viscosity were determined. Standard methods were used during determinations. The 10 kGy dose had no effect on microbial load of un-malted flour but reduced that of malted flour by 3 log cycles. Re-irradiation resulted in complete decontamination. Irradiation of malt caused a significant (p<0.05) reduction in alpha and beta amylase activity (22% and 32%, respectively). Irradiation of un-malted flour increased the rates of utilization of glucose and maltose by 53% and 100%, respectively, during fermentation. However, microbial growth, rate of lactic acid production, final lactic acid concentration and pH were not affected. Starch granules appeared normal externally even after re-irradiation, however, granules ruptured and dissolved easily after hydration and gelatinization. Production of high dry matter density porridge (200 g dry matter/L) with a viscosity of 3500 cP was achieved by irradiation of un-malted flout at 10 kGy. Gamma irradiation can be used to decontaminate flours and could be utilized to produce weaning porridge from sorghum. - Highlights: ► Malted and un-malted Sorghum flours irradiated (10 kGy) and re-irradiated (25 kGy). ► Complete decontamination only achieved after re-irradiation. ► Significant reduction (p<0.05) in malt amylase activity. ► Microbial growth, starch breakdown and acidification unaffected during fermentation. ► Viscosity of sorghum porridge lowered due to weakened starch granules.

Agro-industrial residues and starch for growth and co-production of polyhydroxyalkanoate copolymer and α-amylase by Bacillus sp. CFR-67

Directory of Open Access Journals (Sweden)

T. R. Shamala

2012-09-01

Full Text Available Polyhydroxyalkanoates (PHA and α-amylase (α-1,4 glucan-4-glucanohydrolase, E.C. 3.2.1.1 were co-produced by Bacillus sp. CFR-67 using unhydrolysed corn starch as a substrate. Bacterial growth and polymer production were enhanced with the supplementation of hydrolysates of wheat bran (WBH or rice bran (RBH individually or in combination (5-20 g L-1, based on weight of soluble substrates-SS. In batch cultivation, a mixture of WBH and RBH (1:1, 10 g L-1 of SS along with ammonium acetate (1.75 g L-1 and corn starch (30 g L-1 produced maximum quantity of biomass (10 g L-1 and PHA (5.9 g L-1. The polymer thus produced was a copolymer of polyhydroxybutyrate-co-hydroxyvalerate of 95:5 to 90:10 mol%. Presence of WBH and corn starch (10-50 g L-1 in the medium enhanced fermentative yield of α-amylase (2-40 U mL-1 min-1. The enzyme was active in a wide range of pH (4-9 and temperature (40-60ºC. This is the first report on simultaneous production of copolymer of bacterial PHA and α-amylase from unhydrolysed corn starch and agro-industrial residues as substrates.

Pilot plant production of glucose from starch with soluble. cap alpha. -amylase and immobilized glucoamylase

Energy Technology Data Exchange (ETDEWEB)

Lee, D D; Reilly, P J; Collins, Jr, E V

1975-01-01

Pilot plant studies were conducted on cooking and thinning of corn starch with free ..cap alpha..-amylase and the conversion of the resulting dextrin with immobilized glucoamylase adsorbed on porous SiO/sub 2/. Feeds of intermediate DE values gave maximum yields unless the flow rate of low DE feeds was decreased. Final DE values and glucose concentrations after dextrin treated with Thermamyl 60 ..cap alpha..-amylase had been further hydrolyzed in an immobilized glucoamylase column, were slightly lower than they were when free glucoamylase was used. Similar results were obtained when dextrin, thinned with HT-1000 ..cap alpha..-amylase, was hydrolyzed at 38/sup 0/ and pH 4.4 in the immobilized glucoamylase column. Free glucoamylase yielded values of DE and glucose almost identical with dextrin thinned with Thermamyl 60 ..cap alpha..-amylase. Yields with the free glucoamylase were also slightly higher than they were with SiO/sub 2/-bound enzyme.

Peculiarities of Enhancing Resistant Starch in Ruminants Using Chemical Methods: Opportunities and Challenges

Directory of Open Access Journals (Sweden)

Qendrim Zebeli

2013-06-01

Full Text Available High-producing ruminants are fed high amounts of cereal grains, at the expense of dietary fiber, to meet their high energy demands. Grains consist mainly of starch, which is easily degraded in the rumen by microbial glycosidases, providing energy for rapid growth of rumen microbes and short-chain fatty acids (SCFA as the main energy source for the host. Yet, low dietary fiber contents and the rapid accumulation of SCFA lead to rumen disorders in cattle. The chemical processing of grains has become increasingly important to confer their starch resistances against rumen microbial glycosidases, hence generating ruminally resistant starch (RRS. In ruminants, unlike monogastric species, the strategy of enhancing resistant starch is useful, not only in lowering the amount of carbohydrate substrates available for digestion in the upper gut sections, but also in enhancing the net hepatic glucose supply, which can be utilized by the host more efficiently than the hepatic gluconeogenesis of SCFA. The use of chemical methods to enhance the RRS of grains and the feeding of RRS face challenges in the practice; therefore, the present article attempts to summarize the most important achievements in the chemical processing methods used to generate RRS, and review advantages and challenges of feeding RRS to ruminants

Investigating the Hydrolysis of Starch Using "a"-Amylase Contained in Dishwashing Detergent and Human Saliva

Science.gov (United States)

Munegumi, Toratane; Inutsuka, Masato; Hayafuji, Yukitaka

2016-01-01

Although saliva has commonly been used to teach about digestion by organisms, the phenomenon of digestion is actually caused by enzymes as catalytic substances. This activity explores the hydrolysis of starch by "a"-amylase in cleaning materials as well as a comparison with the similar reaction using human saliva. The fact that the…

Fermentation of starch by Klebsiella oxytoca P2, containing plasmids with {alpha}-amylase and pullulanase genes

Energy Technology Data Exchange (ETDEWEB)

Santos, V.L. dos; Araujo, E.F.; Barros, E.G. de; Guimaraes, W.V.

1999-12-20

Klebsiella oxytoca P2(pC46), an ethanol-producing recombinant, has been evaluated in fermentation of maltose and starch. The maximum ethanol produced by P2(pC46) was 0.34 g ethanol/g maltose and 0.38, 0.40, or 0.36 g ethanol/g starch in fermentation of 1, 2, or 4% starch, representing 68, 71, and 64% the theoretical yield. The pC46 plasmid transformed to cells of K. oxytoca P2 reduced the ethanol production from maltose and starch. In fermentation of starch after its digestion at 60 C for 24 h, in two-step fermentation, the time for maximum ethanol production was reduced to 12--24 h and the theoretical yield was around 90%. The increase in starch concentration resulted in lower {alpha}-amylase activity but in higher pullulanase activity. The high activity and thermostability of the amylolytic enzymes from this transformant suggest that it has a potential for amylolytic enzymes source.

Monitoring of soluble starch hydrolysis induced by α-amylase from Aspergillus oryzae using ultrasonic spectroscopy

Science.gov (United States)

Sierra, Carlos; Resa, Pablo; Buckin, Vitaly; Elvira, Luis

2012-05-01

The online monitoring of enzymatic starch hydrolysis is an important issue for several industrial sectors, mainly in the alimentary industry. Ultrasonic non-invasive methods based on the detection of wave velocity and amplitude changes can be used to study this enzymatic reaction. These wave propagating changes are result of physicalchemical modifications produced in the media by the starch hydrolysis. In this work the starch hydrolysis induced by the enzyme α-amylase from Aspergillus oryzae is studied. This biochemical reaction has been monitored using a high-resolution ultrasonic spectroscopy (HR-US) which is non-invasive and nondestructive. The measured time profiles o of ultrasonic velocity are explained in terms of the starch hydrolysis and the subsequent production of oligosaccharides as a consequence of the enzymatic action. The obtained results have been compared to a conventional off-line technique used in biochemistry, the iodine-starch reaction, a spectrophotometric method to quantify the amount of starch remaining in the medium. The combination of these two types of measurement provides more complete information about the biochemical processes occurred during hydrolysis.

Resistant starch: promise for improving human health.

Science.gov (United States)

Birt, Diane F; Boylston, Terri; Hendrich, Suzanne; Jane, Jay-Lin; Hollis, James; Li, Li; McClelland, John; Moore, Samuel; Phillips, Gregory J; Rowling, Matthew; Schalinske, Kevin; Scott, M Paul; Whitley, Elizabeth M

2013-11-01

Ongoing research to develop digestion-resistant starch for human health promotion integrates the disciplines of starch chemistry, agronomy, analytical chemistry, food science, nutrition, pathology, and microbiology. The objectives of this research include identifying components of starch structure that confer digestion resistance, developing novel plants and starches, and modifying foods to incorporate these starches. Furthermore, recent and ongoing studies address the impact of digestion-resistant starches on the prevention and control of chronic human diseases, including diabetes, colon cancer, and obesity. This review provides a transdisciplinary overview of this field, including a description of types of resistant starches; factors in plants that affect digestion resistance; methods for starch analysis; challenges in developing food products with resistant starches; mammalian intestinal and gut bacterial metabolism; potential effects on gut microbiota; and impacts and mechanisms for the prevention and control of colon cancer, diabetes, and obesity. Although this has been an active area of research and considerable progress has been made, many questions regarding how to best use digestion-resistant starches in human diets for disease prevention must be answered before the full potential of resistant starches can be realized.

Genome mining for new α-amylase and glucoamylase encoding sequences and high level expression of a glucoamylase from Talaromyces stipitatus for potential raw starch hydrolysis.

Science.gov (United States)

Xiao, Zhizhuang; Wu, Meiqun; Grosse, Stephan; Beauchemin, Manon; Lévesque, Michelle; Lau, Peter C K

2014-01-01

Mining fungal genomes for glucoamylase and α-amylase encoding sequences led to the selection of 23 candidates, two of which (designated TSgam-2 and NFamy-2) were advanced to testing for cooked or raw starch hydrolysis. TSgam-2 is a 66-kDa glucoamylase recombinantly produced in Pichia pastoris and originally derived for Talaromyces stipitatus. When harvested in a 20-L bioreactor at high cell density (OD600 > 200), the secreted TSgam-2 enzyme activity from P. pastoris strain GS115 reached 800 U/mL. In a 6-L working volume of a 10-L fermentation, the TSgam-2 protein yield was estimated to be ∼8 g with a specific activity of 360 U/mg. In contrast, the highest activity of NFamy-2, a 70-kDa α-amylase originally derived from Neosartorya fischeri, and expressed in P. pastoris KM71 only reached 8 U/mL. Both proteins were purified and characterized in terms of pH and temperature optima, kinetic parameters, and thermostability. TSgam-2 was more thermostable than NFamy-2 with a respective half-life (t1/2) of >300 min at 55 °C and >200 min at 40 °C. The kinetic parameters for raw starch adsorption of TSgam-2 and NFamy-2 were also determined. A combination of NFamy-2 and TSgam-2 hydrolyzed cooked potato and triticale starch into glucose with yields, 71-87 %, that are competitive with commercially available α-amylases. In the hydrolysis of raw starch, the best hydrolysis condition was seen with a sequential addition of 40 U of a thermostable Bacillus globigii amylase (BgAmy)/g starch at 80 °C for 16 h, and 40 U TSgam-2/g starch at 45 °C for 24 h. The glucose released was 8.7 g/10 g of triticale starch and 7.9 g/10 g of potato starch, representing 95 and 86 % of starch degradation rate, respectively.

A stochastic model for predicting dextrose equivalent and saccharide composition during hydrolysis of starch by alpha-amylase

NARCIS (Netherlands)

Besselink, T.; Baks, T.; Janssen, A.E.M.; Boom, R.M.

2008-01-01

A stochastic model was developed that was used to describe the formation and breakdown of all saccharides involved during -amylolytic starch hydrolysis in time. This model is based on the subsite maps found in literature for Bacillus amyloliquefaciens -amylase (BAA) and Bacillus licheniformis

Application of microbial α-amylase in industry - A review

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Paula Monteiro de Souza

2010-12-01

Full Text Available Amylases are one of the main enzymes used in industry. Such enzymes hydrolyze the starch molecules into polymers composed of glucose units. Amylases have potential application in a wide number of industrial processes such as food, fermentation and pharmaceutical industries. α-Amylases can be obtained from plants, animals and microorganisms. However, enzymes from fungal and bacterial sources have dominated applications in industrial sectors. The production of α-amylase is essential for conversion of starches into oligosaccharides. Starch is an important constituent of the human diet and is a major storage product of many economically important crops such as wheat, rice, maize, tapioca, and potato. Starch-converting enzymes are used in the production of maltodextrin, modified starches, or glucose and fructose syrups. A large number of microbial α-amylases has applications in different industrial sectors such as food, textile, paper and detergent industries. The production of α-amylases has generally been carried out using submerged fermentation, but solid state fermentation systems appear as a promising technology. The properties of each α-amylase such as thermostability, pH profile, pH stability, and Ca-independency are important in the development of fermentation process. This review focuses on the production of bacterial and fungal α-amylases, their distribution, structural-functional aspects, physical and chemical parameters, and the use of these enzymes in industrial applications.

Application of microbial α-amylase in industry - A review.

Science.gov (United States)

de Souza, Paula Monteiro; de Oliveira Magalhães, Pérola

2010-10-01

Amylases are one of the main enzymes used in industry. Such enzymes hydrolyze the starch molecules into polymers composed of glucose units. Amylases have potential application in a wide number of industrial processes such as food, fermentation and pharmaceutical industries. α-Amylases can be obtained from plants, animals and microorganisms. However, enzymes from fungal and bacterial sources have dominated applications in industrial sectors. The production of α-amylase is essential for conversion of starches into oligosaccharides. Starch is an important constituent of the human diet and is a major storage product of many economically important crops such as wheat, rice, maize, tapioca, and potato. Starch-converting enzymes are used in the production of maltodextrin, modified starches, or glucose and fructose syrups. A large number of microbial α-amylases has applications in different industrial sectors such as food, textile, paper and detergent industries. The production of α-amylases has generally been carried out using submerged fermentation, but solid state fermentation systems appear as a promising technology. The properties of each α-amylase such as thermostability, pH profile, pH stability, and Ca-independency are important in the development of fermentation process. This review focuses on the production of bacterial and fungal α-amylases, their distribution, structural-functional aspects, physical and chemical parameters, and the use of these enzymes in industrial applications.

ENZYME RESISTANCE OF GENETICALLY MODIFIED STARCH POTATOES

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A. Sh. Mannapova

2015-01-01

Full Text Available Here in this article the justification of expediency of enzyme resistant starch use in therapeutic food products is presented . Enzyme resistant starch is capable to resist to enzymatic hydrolysis in a small intestine of a person, has a low glycemic index, leads to decrease of postprandial concentration of glucose, cholesterol, triglycerides in blood and insulin reaction, to improvement of sensitivity of all organism to insulin, to increase in sense of fulness and to reduction of adjournment of fats. Resistant starch makes bifidogenшс impact on microflora of a intestine of the person, leads to increase of a quantity of lactobacillus and bifidobacterium and to increased production of butyric acid in a large intestine. In this regard the enzyme resistant starch is an important component in food for prevention and curing of human diseases such as diabetes, obesity, colitis, a cancer of large and direct intestine. One method is specified by authors for imitation of starch digestion in a human body. This method is based on the definition of an enzyme resistance of starch in vitro by its hydrolysis to glucose with application of a glucoamylase and digestive enzyme preparation Pancreatin. This method is used in researches of an enzyme resistance of starch, of genetically modified potato, high amylose corn starch Hi-Maize 1043 and HYLON VII (National Starch Food Innovation, USA, amylopectin and amylose. It is shown that the enzyme resistance of the starch emitted from genetically modified potatoes conforms to the enzyme resistance of the high amylose corn starch “Hi-Maize 1043 and HYLON VII starch”, (National Starch Food Innovation, the USA relating to the II type of enzyme resistant starch. It is established that amylopectin doesn't have the enzyme resistant properties. The results of researches are presented. They allow us to make the following conclusion: amylose in comparison with amylopectin possesses higher enzyme resistance and gives to

Surface binding sites in amylase have distinct roles in recognition of starch structure motifs and degradation

DEFF Research Database (Denmark)

Cockburn, Darrell; Nielsen, Morten M.; Christiansen, Camilla

2015-01-01

degrading enzymes and critically important for their function. The affinity towards a variety of starch granules as well as soluble poly- and oligosaccharides of barley alpha-amylase 1 (AMY1) wild-type and mutants of two SBSs (SBS1 and SBS2) was investigated using Langmuir binding analysis, confocal laser...

Method for using a yeast alpha-amylase promoter

Science.gov (United States)

Gao, Johnway; Skeen, Rodney S.; Hooker, Brian S.; Anderson, Daniel B.

2003-04-22

The present invention provides the promoter clone discovery of an alpha-amylase gene of a starch utilizing yeast strain Schwanniomyces castellii. The isolated alpha-amylase promoter is an inducible promoter, which can regulate strong gene expression in starch culture medium.

Mutations in durum wheat SBEII genes conferring increased amylose and resistant starch affect grain yield components, semolina and pasta quality and fermentation responses in rats

Science.gov (United States)

Increased amylose in wheat (Triticum spp.) starch is associated with increased resistant starch, a fermentable dietary fiber. Fermentation of resistant starch in the large intestine produces short-chain fatty acids that provide human health benefits. Since wheat foods are an important component of t...

Application of microbial α-amylase in industry – A review

Science.gov (United States)

de Souza, Paula Monteiro; de Oliveira Magalhães, Pérola

2010-01-01

Amylases are one of the main enzymes used in industry. Such enzymes hydrolyze the starch molecules into polymers composed of glucose units. Amylases have potential application in a wide number of industrial processes such as food, fermentation and pharmaceutical industries. α-Amylases can be obtained from plants, animals and microorganisms. However, enzymes from fungal and bacterial sources have dominated applications in industrial sectors. The production of α-amylase is essential for conversion of starches into oligosaccharides. Starch is an important constituent of the human diet and is a major storage product of many economically important crops such as wheat, rice, maize, tapioca, and potato. Starch-converting enzymes are used in the production of maltodextrin, modified starches, or glucose and fructose syrups. A large number of microbial α-amylases has applications in different industrial sectors such as food, textile, paper and detergent industries. The production of α-amylases has generally been carried out using submerged fermentation, but solid state fermentation systems appear as a promising technology. The properties of each α-amylase such as thermostability, pH profile, pH stability, and Ca-independency are important in the development of fermentation process. This review focuses on the production of bacterial and fungal α-amylases, their distribution, structural-functional aspects, physical and chemical parameters, and the use of these enzymes in industrial applications. PMID:24031565

Effect of gelatinization and hydrolysis conditions on the selectivity of starch hydrolysis with alpha-amylase from Bacillus licheniformis.

Science.gov (United States)

Baks, Tim; Bruins, Marieke E; Matser, Ariette M; Janssen, Anja E M; Boom, Remko M

2008-01-23

Enzymatic hydrolysis of starch can be used to obtain various valuable hydrolyzates with different compositions. The effects of starch pretreatment, enzyme addition point, and hydrolysis conditions on the hydrolyzate composition and reaction rate during wheat starch hydrolysis with alpha-amylase from Bacillus licheniformis were compared. Suspensions of native starch or starch gelatinized at different conditions either with or without enzyme were hydrolyzed. During hydrolysis, the oligosaccharide concentration, the dextrose equivalent, and the enzyme activity were determined. We found that the hydrolyzate composition was affected by the type of starch pretreatment and the enzyme addition point but that it was just minimally affected by the pressure applied during hydrolysis, as long as gelatinization was complete. The differences between hydrolysis of thermally gelatinized, high-pressure gelatinized, and native starch were explained by considering the granule structure and the specific surface area of the granules. These results show that the hydrolyzate composition can be influenced by choosing different process sequences and conditions.

The adsorption of α-amylase on barley proteins affects the in vitro digestion of starch in barley flour.

Science.gov (United States)

Yu, Wenwen; Zou, Wei; Dhital, Sushil; Wu, Peng; Gidley, Michael J; Fox, Glen P; Gilbert, Robert G

2018-02-15

The conversion of barley starch to sugars is a complex enzymic process. Most previous work concerned the biotechnical aspect of in situ barley enzymes. However, the interactions among the macromolecular substrates and their effects on enzymic catalysis has been little examined. Here, we explore the mechanisms whereby interactions of protein and starch in barley flour affect the kinetics of enzymatic hydrolysis of starch in an in vitro system, using digestion rate data and structural analysis by confocal microscopy. The degradation kinetics of both uncooked barley flour and of purified starches are found to be two-step sequential processes. Barley proteins, especially the water-soluble component, are found to retard the digestion of starch degraded by α-amylase: the enzyme binds with water-insoluble protein and with starch granules, leading to reduced starch hydrolysis. These findings are of potential industrial value in both the brewing and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cloning and expression of acidstable, high maltose-forming, Ca2+-independent α-amylase from an acidophile Bacillus acidicola and its applicability in starch hydrolysis.

Science.gov (United States)

Sharma, Archana; Satyanarayana, T

2012-05-01

The α-amylase encoding gene from acidophilic bacterium Bacillus acidicola was cloned into pET28a(+) vector and expressed in Escherichia coli BL21 (DE3). The recombinant E. coli produced a 15-fold higher α-amylase than B. acidicola strain. The recombinant α-amylase was purified to homogeneity by one-step nickel affinity chromatography using Ni(2+)-NTA resin with molecular mass of 62 KDa. It is active in the pH range between 3.0 and 7.0 and 30 and 100 °C with optimum at pH 4.0 and 60 °C. The enzyme is Ca(2+)-independent with K (m) and k (cat) values (on soluble starch) of 1.6 mg ml(-1) and 108.7 s(-1), respectively. The α-amylase of B. acidicola is acidstable, high maltose forming and Ca(2+)-independent, and therefore, is a suitable candidate for starch hydrolysis and baking.

Immobilization of α-amylase and amyloglucosidase onto ion-exchange resin beads and hydrolysis of natural starch at high concentration.

Science.gov (United States)

Gupta, Kapish; Jana, Asim Kumar; Kumar, Sandeep; Maiti, Mithu

2013-11-01

α-Amylase was immobilized on Dowex MAC-3 with 88 % yield and amyloglucosidase on Amberlite IRA-400 ion-exchange resin beads with 54 % yield by adsorption process. Immobilized enzymes were characterized to measure the kinetic parameters and optimal operational parameters. Optimum substrate concentration and temperature were higher for immobilized enzymes. The thermal stability of the enzymes enhanced after the immobilization. Immobilized enzymes were used in the hydrolysis of the natural starch at high concentration (35 % w/v). The time required for liquefaction of starch to 10 dextrose equivalent (DE) and saccharification of liquefied starch to 96 DE increased. Immobilized enzymes showed the potential for use in starch hydrolysis as done in industry.

Growth temperature of different local isolates of Bacillus sp. in the solid state affects production of raw starch digesting amylases

Directory of Open Access Journals (Sweden)

Šokarda-Slavić Marinela

2014-01-01

Full Text Available Natural amylase producers, wild type strains of Bacillus sp., were isolated from different regions of Serbia. Strains with the highest amylase activity based on the starch-agar plate test were grown on solid-state fermentation (SSF on triticale. The influence of the substrate and different cultivation temperature (28 and 37°C on the production of amylase was examined. The tested strains produced α-amylases when grown on triticale grains both at 28 and at 37°C, but the activity of amylases and the number and intensity of the produced isoforms were different. Significant hydrolysis of raw cornstarch was obtained with the Bacillus sp. strains 2B, 5B, 18 and 24B. The produced α-amylases hydrolyzed raw cornstarch at a temperature below the temperature of gelatinization, but the ability for hydrolysis was not directly related to the total enzyme activity, suggesting that only certain isoforms are involved in the hydrolysis. [Projekat Ministarstva nauke Republike Srbije, br. 172048

Development of functional milk desserts enriched with resistant starch based on consumers' perception.

Science.gov (United States)

Ares, Florencia; Arrarte, Eloísa; De León, Tania; Ares, Gastón; Gámbaro, Adriana

2012-10-01

Sensory characteristics play a key role in determining consumers' acceptance of functional foods. In this context, the aim of the present work was to apply a combination of sensory and consumer methodologies to the development of chocolate milk desserts enriched with resistant starch. Chocolate milk desserts containing modified waxy maize starch were formulated with six different concentrations of two types of resistant starch (which are part of insoluble dietary fiber). The desserts were evaluated by trained assessors using Quantitative Descriptive Analysis. Moreover, consumers scored their overall liking and willingness to purchase and answered an open-ended question. Resistant starch caused significant changes in the sensory characteristics of the desserts and a significant decrease in consumers' overall liking and willingness to purchase. Consumer data was analyzed applying survival analysis on overall liking scores, considering the risk on consumers liking and willing to purchase the functional products less than their regular counterparts. The proposed methodologies proved to be useful to develop functional foods taking into account consumers' perception, which could increase their success in the market.

Mice fed a high-fat diet supplemented with resistant starch display marked shifts in the liver metabolome concurrent with altered gut bacteria

Science.gov (United States)

High-amylose maize resistant starch type 2 (HAMRS2) is a fermentable dietary fiber known to alter the gut milieu, including the gut microbiota, which may explain reported effects of resistant starch to ameliorate obesity-associated metabolic dysfunction. Our working hypothesis is that HAMRS2-induced...

Molecular cloning and biochemical characterization of an α-amylase family from Aspergillus niger

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Junying Wang

2018-03-01

Full Text Available Background: α-Amylase is widely used in the starch processing, food and paper industries, hydrolyzing starch, glycogen and other polysaccharides into glucose, maltose and oligosaccharides. An α-amylase gene family from Aspergillus niger CBS513.88 encode eight putative α-amylases. The differences and similarities, biochemical properties and functional diversity among these eight α-amylases remain unknown. Results: The eight genes were cloned and expressed in Pichia pastoris GS115 by shaking-flask fermentation under the induction of methanol. The sequence alignment, biochemical characterizations and product analysis of starch hydrolysis by these α-amylases were investigated. It is found that the eight α-amylases belonged to three different groups with the typical structure of fungal α-amylase. They exhibited maximal activities at 30–40°C except AmyG and were all stable at acidic pH. Ca2+ and EDTA had no effects on the activities of α-amylases except AmyF and AmyH, indicating that the six amylases were Ca2+ independent. Two novel α-amylases of AmyE and AmyF were found. AmyE hydrolyzed starch into maltose, maltotriose and a small amount of glucose, while AmyF hydrolyzed starch into mainly glucose. The excellent physical and chemical properties including high acidic stability, Ca2+-independent and high maltotriose-forming capacity make AmyE suitable in food and sugar syrup industries. Conclusions: This study illustrates that a gene family can encode multiple enzymes members having remarkable differences in biochemical properties. It provides not only new insights into evolution and functional divergence among different members of an α-amylase family, but the development of new enzymes for industrial application. Keywords: Biochemical properties, Food industry, Fungal α-amylase, Glycosyl hydrolase family, Glycosyl hydrolase family, Industrial application, Paper industry, Recombinant Pichia pastoris, Starch processing, α-amylase cloning

ISOLATION AND IDENTIFICATION OF AMYLASE PRODUCING YEASTS IN ‘TELLA’ (ETHIOPIAN LOCAL BEER AND THEIR AMYLASE CONTRIBUTION FOR ‘TELLA’ PRODUCTION

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Berhanu Andualem

2013-08-01

Full Text Available ‘Tella’ is local beer which is used in most part of Ethiopia. It is made from cereals, such as barley, wheat, maize and other crops. Rhamnus prinoides is also used to provide a special aroma and flavor as well as antiseptic agent. The objective of this study is to determine the contribution of amylases from tella yeast isolates and compare with the role of amylase from malt. House hold ‘tella’ samples were collected and plated on starch agar and then amylase positive isolates of yeast were identified by folding iodine solution over the starch agar. Amylase assay and activities were investigated by standard methods and compared with amylase from malt. According to this study, the activity of amylases which was extracted from yeast isolates was very low and may have no contribution in the conversion of starch into fermentable sugars. Thus, it is better to avoid such organisms from ‘tella’ fermentation in order to discriminate unwanted bio-products. In conclusion, the substrates and ingredients should be sterilized and introduced into the fermentation system aseptically.

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......-amylase 1 (AMY1) fused C-terminally to this SBD via a 37 residue GA-I linker segment. AMY1-SBD was expressed in A. niger, secreted using the AMY1 signal sequence at 25 mg x L(-1) and purified in 50% yield. AMY1-SBD contained 23% carbohydrate and consisted of correctly N-terminally processed multiple forms...... 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...

Molecular cloning of alpha-amylases from cotton boll weevil, Anthonomus grandis and structural relations to plant inhibitors: an approach to insect resistance.

Science.gov (United States)

Oliveira-Neto, Osmundo B; Batista, João A N; Rigden, Daniel J; Franco, Octávio L; Falcão, Rosana; Fragoso, Rodrigo R; Mello, Luciane V; dos Santos, Roseane C; Grossi-de-Sá, Maria F

2003-01-01

Anthonomus grandis, the cotton boll weevil, causes severe cotton crop losses in North and South America. Here we demonstrate the presence of starch in the cotton pollen grains and young ovules that are the main A. grandis food source. We further demonstrate the presence of alpha-amylase activity, an essential enzyme of carbohydrate metabolism for many crop pests, in A. grandis midgut. Two alpha-amylase cDNAs from A. grandis larvae were isolated using RT-PCR followed by 5' and 3' RACE techniques. These encode proteins with predicted molecular masses of 50.8 and 52.7kDa, respectively, which share 58% amino acid identity. Expression of both genes is induced upon feeding and concentrated in the midgut of adult insects. Several alpha-amylase inhibitors from plants were assayed against A. grandis alpha-amylases but, unexpectedly, only the BIII inhibitor from rye kernels proved highly effective, with inhibitors generally active against other insect amylases lacking effect. Structural modeling of Amylag1 and Amylag2 showed that different factors seem to be responsible for the lack of effect of 0.19 and alpha-AI1 inhibitors on A. grandis alpha-amylase activity. This work suggests that genetic engineering of cotton to express alpha-amylase inhibitors may offer a novel route to A. grandis resistance.

Obesity, starch digestion and amylase: association between copy number variants at human salivary (AMY1) and pancreatic (AMY2) amylase genes.

Science.gov (United States)

Carpenter, Danielle; Dhar, Sugandha; Mitchell, Laura M; Fu, Beiyuan; Tyson, Jess; Shwan, Nzar A A; Yang, Fengtang; Thomas, Mark G; Armour, John A L

2015-06-15

The human salivary amylase genes display extensive copy number variation (CNV), and recent work has implicated this variation in adaptation to starch-rich diets, and in association with body mass index. In this work, we use paralogue ratio tests, microsatellite analysis, read depth and fibre-FISH to demonstrate that human amylase CNV is not a smooth continuum, but is instead partitioned into distinct haplotype classes. There is a fundamental structural distinction between haplotypes containing odd or even numbers of AMY1 gene units, in turn coupled to CNV in pancreatic amylase genes AMY2A and AMY2B. Most haplotypes have one copy each of AMY2A and AMY2B and contain an odd number of copies of AMY1; consequently, most individuals have an even total number of AMY1. In contrast, haplotypes carrying an even number of AMY1 genes have rearrangements leading to CNVs of AMY2A/AMY2B. Read-depth and experimental data show that different populations harbour different proportions of these basic haplotype classes. In Europeans, the copy numbers of AMY1 and AMY2A are correlated, so that phenotypic associations caused by variation in pancreatic amylase copy number could be detected indirectly as weak association with AMY1 copy number. We show that the quantitative polymerase chain reaction (qPCR) assay previously applied to the high-throughput measurement of AMY1 copy number is less accurate than the measures we use and that qPCR data in other studies have been further compromised by systematic miscalibration. Our results uncover new patterns in human amylase variation and imply a potential role for AMY2 CNV in functional associations. © The Author 2015. Published by Oxford University Press.

Obesity, starch digestion and amylase: association between copy number variants at human salivary (AMY1) and pancreatic (AMY2) amylase genes

Science.gov (United States)

Carpenter, Danielle; Dhar, Sugandha; Mitchell, Laura M.; Fu, Beiyuan; Tyson, Jess; Shwan, Nzar A.A.; Yang, Fengtang; Thomas, Mark G.; Armour, John A.L.

2015-01-01

The human salivary amylase genes display extensive copy number variation (CNV), and recent work has implicated this variation in adaptation to starch-rich diets, and in association with body mass index. In this work, we use paralogue ratio tests, microsatellite analysis, read depth and fibre-FISH to demonstrate that human amylase CNV is not a smooth continuum, but is instead partitioned into distinct haplotype classes. There is a fundamental structural distinction between haplotypes containing odd or even numbers of AMY1 gene units, in turn coupled to CNV in pancreatic amylase genes AMY2A and AMY2B. Most haplotypes have one copy each of AMY2A and AMY2B and contain an odd number of copies of AMY1; consequently, most individuals have an even total number of AMY1. In contrast, haplotypes carrying an even number of AMY1 genes have rearrangements leading to CNVs of AMY2A/AMY2B. Read-depth and experimental data show that different populations harbour different proportions of these basic haplotype classes. In Europeans, the copy numbers of AMY1 and AMY2A are correlated, so that phenotypic associations caused by variation in pancreatic amylase copy number could be detected indirectly as weak association with AMY1 copy number. We show that the quantitative polymerase chain reaction (qPCR) assay previously applied to the high-throughput measurement of AMY1 copy number is less accurate than the measures we use and that qPCR data in other studies have been further compromised by systematic miscalibration. Our results uncover new patterns in human amylase variation and imply a potential role for AMY2 CNV in functional associations. PMID:25788522

Baking Performance of Phosphorylated Cross-Linked Resistant Starch in Low-Moisture Bakery Goods

Science.gov (United States)

Phosphorylated cross-linked resistant starch (RS) is a type 4 RS, which can be used for enhancing the benefits of dietary fiber. The baking performance of the RS was explored using wire-cut cookie baking and benchtop chemically-leavened cracker baking methods to produce low-moisture baked goods (coo...

Enhanced Production and Characterization of a Solvent Stable Amylase from Solvent Tolerant Bacillus tequilensis RG-01: Thermostable and Surfactant Resistant

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Soni Tiwari

2014-01-01

Full Text Available Ten bacterial strains isolated from the soil samples in the presence of cyclohexane were screened for amylase production. Among them, culture RG-01 was adjudged as the best amylase producer and was identified as Bacillus tequilensis from MTCC, Chandigarh. The isolate showed maximum amylase production (8100 U/mL in the presence of starch, peptone, and Ca2+ ions at 55°C pH 7.0 within 24 h of incubation. The enzyme was stable in the presence of n-dodecane, isooctane, n-decane, xylene, toluene, n-hexane, n-butanol, and cyclohexane, respectively. The presence of benzene, methanol, and ethanol marginally reduced the amylase stability, respectively. The enzyme was showed it 100% activity at 55°C and pH 7.0 with 119% and 127% stability at 55°C and pH 7.0, respectively. The enzyme was also stable in the presence of SDS, Tween-40, Tween-60, and Tween-80 (1% and was found stimulatory effect, respectively. Only Triton-X-100 showed a moderate inhibitory effect (5% on amylase activity. This isolate (Bacillus tequilensis RG-01 may be useful in several industrial applications owing to its thermotolerant and organic solvents and surfactants resistance characteristics.

Optimization, Purification, and Starch Stain Wash Application of Two New α-Amylases Extracted from Leaves and Stems of Pergularia tomentosa

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Imen Lahmar

2017-01-01

Full Text Available A continuous research is attempted to fulfil the highest industrial demands of natural amylases presenting special properties. New α-amylases extracted from stems and leaves of Pergularia tomentosa, which is widespread and growing spontaneously in Tunisia, were studied by the means of their activities optimization and purification. Some similarities were recorded for the two identified enzymes: (i the highest amylase activity showed a promoted thermal stability at 50°C; (ii the starch substrate at 1% enhanced the enzyme activity; (iii the two α-amylases seem to be calcium-independent; (iv Zn2+, Cu2+, and Ag2+ were considered as important inhibitors of the enzyme activity. Following the increased gradient of elution on Mono Q-Sepharose column, an increase in the specific activity of 11.82-fold and 10.92-fold was recorded, respectively, for leaves and stems with the presence of different peaks on the purification profiles. Pergularia amylases activities were stable and compatible with the tested commercial detergents. The combination of plant amylase and detergent allowed us to enhance the wash performance with an increase of 35.24 and 42.56%, respectively, for stems and leaves amylases. Characterized amylases were reported to have a promoted potential for their implication notably in detergent industry as well as biotechnological sector.

Application of autoclaving-cooling cycling treatment to improve resistant starch content of corn-based rice analogues

Science.gov (United States)

Hidayat, B.; Muslihudin, M.; Akmal, S.

2018-01-01

Resistant starch is one important component determining the characteristics of a functional food. The aim of the research was to determine the cooling time optimum in the autoclaving-cooling treatment to increase the resistance starch content corn-based rice analogues, with 6 level of cooling time (0 hours/control, 12 hours, 24 hours, 36 hours, 48 hours and 60 hours). The results showed that cooling at 4°C for 60 hours would increase the resistant starch content (6.27% to 15.38%), dietary fiber content (14.53% to 20.17%); and decrease the digestible starch content (61.81% to 52.70%). Cooling time level at 4°C for 24 hours, would increase the sensory score of corn-based rice analogues then back down until cooling time level of 60 hours. Microscopic analysis of granular structure using SEM indicated that cooling time had a linear correlation with cracks intensity on the granule surface of the corn-based rice analogues. The high content of resistant starch showed that the application of cooling time level at 4°C for 24 hours would improve the functional properties of corn-based rice analogues with sensory characteristics remain favorable to panelists.

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

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

Synthesis of supermacroporous cryogel for bioreactors continuous starch hydrolysis.

Science.gov (United States)

Guilherme, Ederson Paulo Xavier; de Oliveira, Jocilane Pereira; de Carvalho, Lorendane Millena; Brandi, Igor Viana; Santos, Sérgio Henrique Sousa; de Carvalho, Gleidson Giordano Pinto; Cota, Junio; Mara Aparecida de Carvalho, Bruna

2017-11-01

A bioreactor was built by means of immobilizing alpha-amylase from Aspergillus oryzae by encapsulation, through cryopolymerization of acrylamide monomers for the continuous starch hydrolysis. The starch hydrolysis was evaluated regarding pH, the concentration of immobilized amylase on cryogel, the concentration of starch solution and temperature. The maximum value for starch hydrolysis was achieved at pH 5.0, concentration of immobilized enzyme 111.44 mg amylase /g cryogel , concentration of starch solution 45 g/L and temperature of 35°C. The immobilized enzyme showed a conversion ratio ranging from 68.2 to 97.37%, depending on the pH and temperature employed. Thus, our results suggest that the alpha-amylase from A. oryzae immobilized on cryogel monoliths represents a potential process for industrial production of maltose from starch hydrolysis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effect of a Brief Salivary α-Amylase Exposure During Chewing on Subsequent in Vitro Starch Digestion Curve Profiles

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Charles S. Brennan

2010-07-01

Full Text Available There is inconsistency between current in vitro digestion methods with regard to accommodation of a (salivary α-amylase exposure during the oral phase. The effect of a salivary α-amylase pre-exposure on subsequent in vitro starch digestion curve profiles for various foods was investigated. Foods were chewed, expectorated and the boluses left to rest for 0–15 min. During pancreatic digestion, aliquots were taken and hydrolysis curves constructed for comparison against those of the same foods comminuted with a manually-operated chopper, hence spared exposure to saliva. Hydrolysate aliquots taken at T0 (time zero of the digestion of chewed samples contained higher levels of glucose and dextrins compared with chopped samples. Pancreatin activity immediately overwhelmed differences in sugar released due to salivary amylase activity. Within 10 min no differences were detectable between hydrolysis curves for chewed and chopped foods. Salivary amylase pretreatment does not contribute to the robustness or relative accuracy of in vitro methods.

Potency of Amylase-producing Bacteria and Optimization Amylase Activities

Science.gov (United States)

Indriati, G.; Megahati, R. R. P.; Rosba, E.

2018-04-01

Enzymes are capable to act as biocatalyst for a wide variety of chemical reactions. Amylase have potential biotechnological applications in a wide range of industrial processes and account for nearly 30% of the world’s enzyme market. Amylase are extracellular enzymes that catalyze the hydrolysis of internal α-1,4-glycosidic linkages in starch to dextrin, and other small carbohydrate molecules constituted of glucose units. Although enzymes are produced from animal and plant sources, the microbial sources are generally the most suitable for commercial applications. Bacteria from hot springs is widely used as a source of various enzymes, such as amylase. But the amount of amylase-producing bacteria is still very limited. Therefore it is necessary to search sources of amylase-producing bacteria new, such as from hot springs Pariangan. The purpose of this study was to isolation of amylase-producing bacteria from Pariangan hot spring, West Sumatera and amylase activity optimization. The results were obtained 12 isolates of thermophilic bacteria and 5 isolates of amyalse-producing bacteria with the largest amylolytic index of 3.38 mm. The highest amylase activity was obtained at 50°C and pH 7.5.

Changes in physicochemical properties and in vitro starch digestion of native and extruded maize flours subjected to branching enzyme and maltogenic α-amylase treatment.

Science.gov (United States)

Román, Laura; Martínez, Mario M; Rosell, Cristina M; Gómez, Manuel

2017-08-01

Extrusion is an increasingly used type of processing which combined with enzymatic action could open extended possibilities for obtaining clean label modified flours. In this study, native and extruded maize flours were modified using branching enzyme (B) and a combination of branching enzyme and maltogenic α-amylase (BMA) in order to modulate their hydrolysis properties. The microstructure, pasting properties, in vitro starch hydrolysis and resistant starch content of the flours were investigated. Whereas BMA treatment led to greater number of holes on the granule surface in native samples, B and BMA extruded samples showed rougher surfaces with cavities. A reduction in the retrogradation trend was observed for B and BMA native flours, in opposition to the flat pasting profile of their extruded counterparts. The glucose release increased gradually for native flours as the time of reaction did, whereas for extruded flours a fast increase of glucose release was observed during the first minutes of reaction, and kept till the end, indicating a greater accessibility to their porous structure. These results suggested that, in enzymatically treated extruded samples, changes produced at larger hierarchical levels in their starch structure could have masked a slowdown in the starch digestion properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Alpha-amylase from the Hyperthermophilic Archaeon Thermococcus thioreducens

Science.gov (United States)

Bernhardsdotter, E. C. M. J.; Pusey, M. L.; Ng, M. L.; Garriott, O. K.

2003-01-01

Extremophiles are microorganisms that thrive in, from an anthropocentric view, extreme environments such as hot springs. The ability of survival at extreme conditions has rendered enzymes from extremophiles to be of interest in industrial applications. One approach to producing these extremozymes entails the expression of the enzyme-encoding gene in a mesophilic host such as E.coli. This method has been employed in the effort to produce an alpha-amylase from a hyperthermophile (an organism that displays optimal growth above 80 C) isolated from a hydrothermal vent at the Rainbow vent site in the Atlantic Ocean. alpha-amylases catalyze the hydrolysis of starch to produce smaller sugars and constitute a class of industrial enzymes having approximately 25% of the enzyme market. One application for thermostable alpha-amylases is the starch liquefaction process in which starch is converted into fructose and glucose syrups. The a-amylase encoding gene from the hyperthermophile Thermococcus thioreducens was cloned and sequenced, revealing high similarity with other archaeal hyperthermophilic a-amylases. The gene encoding the mature protein was expressed in E.coli. Initial characterization of this enzyme has revealed an optimal amylolytic activity between 85-90 C and around pH 5.3-6.0.

Cloning of a yeast alpha-amylase promoter and its regulated heterologous expression

Science.gov (United States)

Gao, Johnway [Richland, WA; Skeen, Rodney S [Pendleton, OR; Hooker, Brian S [Kennewick, WA; Anderson, Daniel B [Pasco, WA

2003-04-01

The present invention provides the promoter clone discovery of an alpha-amylase gene of a starch utilizing yeast strain Schwanniomyces castellii. The isolated alpha-amylase promoter is an inducible promoter, which can regulate strong gene expression in starch culture medium.

Rethinking the starch digestion hypothesis for AMY1 copy number variation in humans.

Science.gov (United States)

Fernández, Catalina I; Wiley, Andrea S

2017-08-01

Alpha-amylase exists across taxonomic kingdoms with a deep evolutionary history of gene duplications that resulted in several α-amylase paralogs. Copy number variation (CNV) in the salivary α-amylase gene (AMY1) exists in many taxa, but among primates, humans appear to have higher average AMY1 copies than nonhuman primates. Additionally, AMY1 CNV in humans has been associated with starch content of diets, and one known function of α-amylase is its involvement in starch digestion. Thus high AMY1 CNV is considered to result from selection favoring more efficient starch digestion in the Homo lineage. Here, we present several lines of evidence that challenge the hypothesis that increased AMY1 CNV is an adaptation to starch consumption. We observe that α- amylase plays a very limited role in starch digestion, with additional steps required for starch digestion and glucose metabolism. Specifically, we note that α-amylase hydrolysis only produces a minute amount of free glucose with further enzymatic digestion and glucose absorption being rate-limiting steps for glucose availability. Indeed α-amylase is nonessential for starch digestion since sucrase-isomaltase and maltase-glucoamylase can hydrolyze whole starch granules while releasing glucose. While higher AMY1 CN and CNV among human populations may result from natural selection, existing evidence does not support starch digestion as the major selective force. We report that in humans α-amylase is expressed in several other tissues where it may have potential roles of evolutionary significance. © 2017 Wiley Periodicals, Inc.

Effect of culture conditions on the activity of amylase used for alcoholic fermentation

Energy Technology Data Exchange (ETDEWEB)

Lee, S.D.; Ryu, Y.H.

1973-01-01

A wheat bran culture was used for media for the mold strains: Aspergillus oryzae, A. kawachii, A. usamii, and Rhizopus javanicus, to determine in which strain the amylase activity could be increased the most. The wheat bran media provided 47, 51, and 55% starch for each strain. To the media were added 3 nitrogen sources, viz.: (NH/sub 4/)/sub 2/SO/sub 4/, casein, and (NH/sub 4/)/sub 2/SO/sub 4/ - casein mixture. Each nitrogen source was made available at 2, 4, and 6% levels except only 2% (NH/sub 4/)/sub 2/SO/sub 4/ was used. The results obtained were as follows: (1) The ..cap alpha..-amylase activity was highest in media with 47% starch and 6% casein. (2) The ..beta..-amylase activity was highest in media with 51% starch and 2% (NH/sub 4/)/sub 2/SO/sub 4/ - casein. (3) Both ..cap alpha..- and ..beta..-amylase activities in A. usamii were highest in the media with 47% starch and no additional nitrogen source. (4) Of the 4 strains examined the ..cap alpha..- and ..beta..-amylase activities in R. javanicus were both relatively the highest. (5) The ..cap alpha..- and ..beta..-amylase activities of the strains examined decreased as the percentage of starch was increased except in R. javanicus.

Production of Alpha Amylase by Bacillus cereus in Submerged Fermentation

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Helen H. Raplong

2014-09-01

Full Text Available Microorganisms have the ability to secrete enzymes when they are grown in the presence of certain substrates. Amylases are among the most important industrial enzymes and are of great significance in biotechnological studies. Bacteria belonging to the genus Bacillus were isolated using mannitol egg yolk polymyxin B (MYP agar a highly selective media for Bacillus cereus isolation. The isolates were tested for α-amylase production on nutrient agar supplemented with starch and in submerged fermentation. The bacteria isolated and identified (using the Microgen Bacillus identification kit were all Bacillus cereus and SB2 had the largest zone of hydrolysis of 12mm on nutrient agar supplemented with starch as well as the highest enzyme activity of 1.62U/ml. Amylase activity of 2.56U/ml was obtained after 24 hours incubation in submerged fermentation. When amylase enzyme production parameters where optimized, maximum amylase activity was obtained at a pH of 6.5, temperature of 350C, incubation time of 24 hours and 4% inoculums concentration. Bacillus cereus SB2 is a potential isolate for alpha-amylase production with soluble starch as the sole carbon source in submerged fermentation.

Thermostable 𝜶-Amylase Activity from Thermophilic Bacteria Isolated from Bora Hot Spring, Central Sulawesi

Science.gov (United States)

Gazali, F. M.; Suwastika, I. N.

2018-03-01

α-Amylase is one of the most important enzyme in biotechnology field, especially in industrial application. Thermostability of α-Amylase produced by thermophilic bacteria improves industrial process of starch degradation in starch industry. The present study were concerned to the characterization of α-Amylase activity from indigenous thermophilic bacteria isolated from Bora hot spring, Central Sulawesi. There were 18 isolates which had successfully isolated from 90°C sediment samples of Bora hot spring and 13 of them showed amylolytic activity. The α-Amylase activity was measured qualitatively at starch agar and quantitatively based on DNS (3,5-Dinitrosalicylic acid) methods, using maltose as standard solution. Two isolates (out of 13 amylolytic bacteria), BR 002 and BR 015 showed amylolytic index of 0.8 mm and 0.5 mm respectively, after being incubated at 55°C in the 0.002% Starch Agar Medium. The α-Amylase activity was further characterized quantitatively which includes the optimum condition of pH and temperature of α-Amylase crude enzyme from each isolate. To our knowledge, this is the first report on isolation and characterization of a thermostable α-Amylase from thermophilic bacteria isolated from Central Sulawesi particularly from Bora hot spring.

Gamma irradiation of sorghum flour: Effects on microbial inactivation, amylase activity, fermentability, viscosity and starch granule structure

Science.gov (United States)

Mukisa, Ivan M.; Muyanja, Charles M. B. K.; Byaruhanga, Yusuf B.; Schüller, Reidar B.; Langsrud, Thor; Narvhus, Judith A.

2012-03-01

Malted and un-malted sorghum ( Sorghum bicolor (L.) Moench) flour was gamma irradiated with a dose of 10 kGy and then re-irradiated with 25 kGy. The effects of irradiation on microbial decontamination, amylase activity, fermentability (using an amylolytic L. plantarum MNC 21 strain), starch granule structure and viscosity were determined. Standard methods were used during determinations. The 10 kGy dose had no effect on microbial load of un-malted flour but reduced that of malted flour by 3 log cycles. Re-irradiation resulted in complete decontamination. Irradiation of malt caused a significant ( palpha and beta amylase activity (22% and 32%, respectively). Irradiation of un-malted flour increased the rates of utilization of glucose and maltose by 53% and 100%, respectively, during fermentation. However, microbial growth, rate of lactic acid production, final lactic acid concentration and pH were not affected. Starch granules appeared normal externally even after re-irradiation, however, granules ruptured and dissolved easily after hydration and gelatinization. Production of high dry matter density porridge (200 g dry matter/L) with a viscosity of 3500 cP was achieved by irradiation of un-malted flout at 10 kGy. Gamma irradiation can be used to decontaminate flours and could be utilized to produce weaning porridge from sorghum.

Starch Spherulites Prepared by a Combination of Enzymatic and Acid Hydrolysis of Normal Corn Starch.

Science.gov (United States)

Shang, Yaqian; Chao, Chen; Yu, Jinglin; Copeland, Les; Wang, Shuo; Wang, Shujun

2018-06-13

This paper describes a new method to prepare spherulites from normal corn starch by a combination of enzymatic (mixtures of α-amylase and amyloglucosidase) and acid hydrolysis followed by recrystallization of the hydrolyzed products. The resulting spherulites contained a higher proportion of chains with a degree of polymerization (DP) of 6-12 and a lower proportion of chains with DP of 25-36, compared to those of native starch. The spherulites had an even particle size of about 2 μm and a typical B-type crystallinity. The amounts of long- and short-range molecular order of double helices in starch spherulites were larger, but the quality of starch crystallites was poorer, compared to that of native starch. This study showed an efficient method for preparing starch spherulites with uniform granule morphology and small particle size from normal corn starch. The ratios of α-amylase and amyloglucosidase in enzymatic hydrolysis had little effect on the structure of the starch spherulites.

Concerted suppression of all starch branching enzyme genes in barley produces amylose-only starch granules

DEFF Research Database (Denmark)

Carciofi, Massimiliano; Blennow, Andreas; Jensen, Susanne L

2012-01-01

to glucose and rapidly absorbed in the small intestine. But a portion of dietary starch, termed "resistant starch" (RS) escapes digestion and reaches the large intestine, where it is fermented by colonic bacteria producing short chain fatty acids (SCFA) which are linked to several health benefits. The RS...

Effects of Arabinoxylan and Resistant Starch on Intestinal Microbiota and Short-Chain Fatty Acids in Subjects with Metabolic Syndrome: A Randomised Crossover Study.

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Stine Hald

Full Text Available Recently, the intestinal microbiota has been emphasised as an important contributor to the development of metabolic syndrome. Dietary fibre may exert beneficial effects through modulation of the intestinal microbiota and metabolic end products. We investigated the effects of a diet enriched with two different dietary fibres, arabinoxylan and resistant starch type 2, on the gut microbiome and faecal short-chain fatty acids. Nineteen adults with metabolic syndrome completed this randomised crossover study with two 4-week interventions of a diet enriched with arabinoxylan and resistant starch and a low-fibre Western-style diet. Faecal samples were collected before and at the end of the interventions for fermentative end-product analysis and 16S ribosomal RNA bacterial gene amplification for identification of bacterial taxa. Faecal carbohydrate residues were used to verify compliance. The diet enriched with arabinoxylan and resistant starch resulted in significant reductions in the total species diversity of the faecal-associated intestinal microbiota but also increased the heterogeneity of bacterial communities both between and within subjects. The proportion of Bifidobacterium was increased by arabinoxylan and resistant starch consumption (P<0.001, whereas the proportions of certain bacterial genera associated with dysbiotic intestinal communities were reduced. Furthermore, the total short-chain fatty acids (P<0.01, acetate (P<0.01 and butyrate concentrations (P<0.01 were higher by the end of the diet enriched with arabinoxylan and resistant starch compared with those resulting from the Western-style diet. The concentrations of isobutyrate (P = 0.05 and isovalerate (P = 0.03 decreased in response to the arabinoxylan and resistant starch enriched diet, indicating reduced protein fermentation. In conclusion, arabinoxylan and resistant starch intake changes the microbiome and short-chain fatty acid compositions, with potential beneficial effects on

A titration approach to identify the capacity for starch digestion in milk-fed calves.

Science.gov (United States)

Gilbert, M S; van den Borne, J J G C; Berends, H; Pantophlet, A J; Schols, H A; Gerrits, W J J

2015-02-01

Calf milk replacers (MR) commonly contain 40% to 50% lactose. For economic reasons, starch is of interest as a lactose replacer. Compared with lactose, starch digestion is generally low in calves. It is, however, unknown which enzyme limits the rate of starch digestion. The objectives were to determine which enzyme limits starch digestion and to assess the maximum capacity for starch digestion in milk-fed calves. A within-animal titration study was performed, where lactose was exchanged stepwise for one of four starch products (SP). The four corn-based SP differed in size and branching, therefore requiring different ratios of starch-degrading enzymes for their complete hydrolysis to glucose: gelatinised starch (α-amylase and (iso)maltase); maltodextrin ((iso)maltase and α-amylase); maltodextrin with α-1,6-branching (isomaltase, maltase and α-amylase) and maltose (maltase). When exceeding the animal's capacity to enzymatically hydrolyse starch, fermentation occurs, leading to a reduced faecal dry matter (DM) content and pH. Forty calves (13 weeks of age) were assigned to either a lactose control diet or one of four titration strategies (n=8 per treatment), each testing the stepwise exchange of lactose for one SP. Dietary inclusion of each SP was increased weekly by 3% at the expense of lactose and faecal samples were collected from the rectum weekly to determine DM content and pH. The increase in SP inclusion was stopped when faecal DM content dropped below 10.6% (i.e. 75% of the average initial faecal DM content) for 3 consecutive weeks. For control calves, faecal DM content and pH did not change over time. For 87% of the SP-fed calves, faecal DM and pH decreased already at low inclusion levels, and linear regression provided a better fit of the data (faecal DM content or pH v. time) than non-linear regression. For all SP treatments, faecal DM content and pH decreased in time (Pdigestion and that fermentation may contribute substantially to total tract starch

High yield of amylase from Aspergillus niger by the effect of gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

El-Saadany, R.M.A.; Salem, F.A.; El-Manawaty, H.K.

1984-02-01

When irradiated rice was used as a media for Aspergillus niger a noticeable increase of amylase production was observed. Molecular degradation of starch molecules did occur, and an increase in starch acidity and solubility was noticed, whereas a marked decrease in viscosity as well as swelling capacity was observed. Gelatinization time and temperature of irradiated starch became shorter or lower resp. These results showed that internal changes in irradiated starch molecules and an alteration in its molecular configuration occured. They may affect the pathway of the growth of the fungi Aspergillus niger. When the amount of amylase was determined by measuring enzyme activity, it was observed that amylases in the irradiated media were higher than in the control media.

Engagement with dietary fibre and receptiveness to resistant starch in Australia.

Science.gov (United States)

Mohr, Philip; Quinn, Sinéad; Morell, Matthew; Topping, David

2010-11-01

To investigate community engagement with the health benefits of dietary fibre (DF) and its potential as a framework for the promotion of increased consumption of resistant starch (RS). A nationwide postal Food and Health Survey conducted in Australia by CSIRO Human Nutrition. Adults aged 18 years and above, selected at random from the Australian Electoral Roll (n 849). A cross-sectional design was employed to analyse ratings of (i) the importance of various RS health and functional claims and (ii) receptiveness to different foods as RS delivery vehicles, according to the respondents' level of fibre engagement as classified under the Precaution Adoption Process Model (PAPM) of Health Behaviour. There was a high level of recognition (89·5 %) of DF as being important for health. Significant gender differences were found for ratings of RS attributes and RS delivery options. Women were both more fibre-engaged than men and more receptive than men to RS and its potential benefits. Ratings of the acceptability of several foods as means of delivering RS revealed a general preference for healthy staples over indulgences, with the margin between acceptability of staples and indulgences increasing markedly with increased fibre engagement. Application of the PAPM to awareness of DF reveals a ready-made target group for health messages about RS and pockets of differential potential receptiveness. The findings support the promotion of RS as providing health benefits of DF with the added reduction of risk of serious disease, its delivery through healthy staples and the targeting of messages at both fibre-engaged individuals and women in general.

Culture medium for amylase production by toxigenic fungi

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Figueira Edson Luiz Zangrando

2000-01-01

Full Text Available Mycelial growth and amylase production by a mycotoxigenic strain of Fusarium moniliforme and Aspergillus flavus were evaluated in a culture medium containing starch, glycerol, wheat bran or corn. With emphasis on corn, different fractions composed by germ, degermed seed, starch, milky stage corn and the respective starch or supernatant fraction were analyzed for F. moniliforme growth . The medium composed of milky stage corn supernatant promoted the best mycelial growth (p<0.05, and it was used to prepare amylase production medium in the next step. The medium composed with 2% ground corn in milky stage corn supernatant (350g of milky stage corn blended with 250mL water and centrifuged promoted the highest amylase production, which was at the 10th day of fermentation, both for F. moniliforme (42.32U/mL and A. flavus (4,745.54U/mL.

Enzyme-resistant dextrins from potato starch for potential application in the beverage industry.

Science.gov (United States)

Jochym, Kamila Kapusniak; Nebesny, Ewa

2017-09-15

The objective of this study was to produce soluble enzyme-resistant dextrins by microwave heating of potato starch acidified with small amounts of hydrochloric and citric acids and to characterize their properties. Twenty five samples were initially made and their solubility was determined. Three samples with the highest water solubility were selected for physico-chemical (dextrose equivalent, molecular weight distribution, pasting characteristics, retrogradation tendency), total dietary fiber (TDF) analysis, and stability tests. TDF content averaged 25%. Enzyme-resistant dextrins practically did not paste, even at 20% samples concentration, and were characterized by low retrogradation tendency. The stability of the samples, expressed as a percentage increase of initial and final reducing sugar content, at low pH and during heating at low pH averaged 10% and 15% of the initial value, respectively. The results indicate that microwave heating could be an effective and efficient method of producing highly-soluble, low-viscous, and enzyme-resistant potato starch dextrins. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation and Characterization of an Amylase Producing Yeast and its Application in Carotenoid Production Using Dual Culture

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Iraj Nahvi

2005-06-01

Full Text Available Starch is a plant polysaccharide with unique applications in Iran. Its increasing production and processing recently have led to large volumes of industrial effluent as an environmental pollutant. In this study, an amylase producing yeast is isolated and identified as “Cryptococcus aerius” to investigate some of its characteristics such as its amylase secretion and starch digesting patterns, kinetics of amylase complex, and its capability for carotenoid production in dual culture. The results indicate that C.aerius is capable of soluble and raw maize starch digestion and assimilation. Raw starch digestion is scarce among yeast species; hence, it is industrially important. C.aerius digests soluble starch in the first 10 hours of cultivation and on the basis of amylase secreting patterns, it is therefore categorized with fast growing species on starch as carbon source. Non-pathogenicity, digestion of raw starch, heat stability of the secreted amylases complex (>55˚C, and the optimum pH level of 5.5- 6 for amylases complex are the set of properties that make this species capable of use in microbial production on an industrial scale. Absorption of carotenoid extract obtained from dual fermentation of C.aerius and Rhodotorula sp. indicates that the quality of carotenoids produced in dual fermentation is the same as that produced from pure Rhodotorula sp culture.

A structured approach to target starch solubilisation and hydrolysis for the sugarcane industry.

Science.gov (United States)

Cole, Marsha R; Rose, Ingrid; Chung, Yoo Jin; Eggleston, Gillian

2015-01-01

In sugarcane processing, starch is considered an impurity that negatively affects processing and reduces the quality of the sugar end-product. In the last decade, there has been a general world-wide increase in starch concentrations in sugarcane. Industrial α-amylases have been used for many years to mitigate issues arising from starch in the sugarcane industry. Mixed results have prompted further studies of the behaviour of different physical forms of starch and their interactions with α-amylases during processing. By using corn starch as a reference in model juices and syrups, processing parameters, activities, and hydrolysis of insoluble, swollen, and soluble starch forms were evaluated for two commercial α-amylases with high (HT) and intermediate (IT) temperature stability, respectively. The ability of starch to solubilise across a sugarcane factory is largely limited by increased Brix values. Optimum target locations and conditions for the application of α-amylases in sugarcane processing are discussed in detail. Published by Elsevier Ltd.

Dietary Variation and Evolution of Gene Copy Number among Dog Breeds.

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Taylor Reiter

Full Text Available Prolonged human interactions and artificial selection have influenced the genotypic and phenotypic diversity among dog breeds. Because humans and dogs occupy diverse habitats, ecological contexts have likely contributed to breed-specific positive selection. Prior to the advent of modern dog-feeding practices, there was likely substantial variation in dietary landscapes among disparate dog breeds. As such, we investigated one type of genetic variant, copy number variation, in three metabolic genes: glucokinase regulatory protein (GCKR, phytanol-CoA 2-hydroxylase (PHYH, and pancreatic α-amylase 2B (AMY2B. These genes code for proteins that are responsible for metabolizing dietary products that originate from distinctly different food types: sugar, meat, and starch, respectively. After surveying copy number variation among dogs with diverse dietary histories, we found no correlation between diet and positive selection in either GCKR or PHYH. Although it has been previously demonstrated that dogs experienced a copy number increase in AMY2B relative to wolves during or after the dog domestication process, we demonstrate that positive selection continued to act on amylase copy number in dog breeds that consumed starch-rich diets in time periods after domestication. Furthermore, we found that introgression with wolves is not responsible for deterioration of positive selection on AMY2B among diverse dog breeds. Together, this supports the hypothesis that the amylase copy number expansion is found universally in dogs.

New insight into structure/function relationships in plant alpha-amylase family GH13 members

DEFF Research Database (Denmark)

Seo, Eun-Seong; Andersen, Joakim Mark; Nielsen, Morten Munch

2010-01-01

Two carbohydrate binding surface sites (SBSs) on barley α-amylase 1 (AMY1) of glycoside hydrolase family 13 (GH13) displayed synergy in interactions with starch granules, thus being pivotal for hydrolysis of supramolecular substrates. Mutational analysis showed that SBS1 is more critical for the ......Two carbohydrate binding surface sites (SBSs) on barley α-amylase 1 (AMY1) of glycoside hydrolase family 13 (GH13) displayed synergy in interactions with starch granules, thus being pivotal for hydrolysis of supramolecular substrates. Mutational analysis showed that SBS1 is more critical...... binding domains (SBDs) mediate binding to starch granules. SBDs are currently categorised into 9 carbohydrate binding module (CBM) families. A novel CBM20 subfamily encountered in regulatory enzymes possesses characteristically low affinity for β-CD. Although α-amylase is essential for starch mobilisation...... in germinating barley seeds, efficient degradation requires the concerted action of α-amylase, β-amylase, limit dextrinase (LD) and possibly α-glucosidase. Limit dextrinase (LD) is encoded by a single gene and represents the sole debranching activity during germination. Recent expression of functional LD...

Importance of amylases for physiological quality in maize seeds

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Camila Aparecida Lopes

2017-09-01

Full Text Available Seed quality is the result of the sum of genetic, physical, physiological and sanitary attributes that affect seed ability to perform vital functions related to germination, vigor, and longevity. The expression of genes associated with physiological quality can be assessed by means of germination and vigor analyses, as well as by transcript and protein analyses. The objective in this work was to review the relevance of amylase group enzymes to the physiological quality of maize seeds. Within this group, α-amylase (1,4-α-D-glucan glucanohydrolase E.C 3.2.1.1 plays an important role in starch hydrolysis, and is responsible for 90% of the amylolytic activity in maize seeds. It is responsible for starch conversion into sugars (e.g., destrin, which is used for embryo growth. β-amylase (1,4-α-D-glucan maltohydrolase E.C 3.2.1.2 catalyzes the release of maltose and dextrins from the non-reducing ends of starch. Research has shown that amylase enzymes are directly linked to physiological quality of maize seeds. Alpha- and beta-amylases are mainly involved in the germination process and seed heterosis, and can also be used as molecular markers associated with seed tolerance for drying.

Influence of media composition on the production of alkaline α-amylase from Bacillus subtilis CB-18.

Science.gov (United States)

Ogbonnaya, Nwokoro; Odiase, Anthonia

2012-01-01

Starch, a homopolysaccharide is an important and an abundant food reserve and energy source. Starches are processed to yield different products which find many industrial applications. Alpha-amylases hydrolyze starch by cleaving α-1,4-glucosidic bonds and have been used in food, textile and pharmaceutical industries [Sun et al. 2010]. Enzymatic conversion of starch with amylase presents an economically superior alternative to the conventional method of starch gelatinization. Alkaline α-amylase has an important position in the global enzyme market as a constituent of detergent. In this paper, we screened soil bacteria and an isolate, alkalophilic Bacillus subtilis CB-18 was found to produce an alkaline α-amylase in different media. MATERIAL AND METHODS. Screening of the isolates for amylolytic activity was carried out by growing bacteria isolated from the soil in starch agar plates and subsequently staining the plates with iodine solution to reveal zones of hydrolysis of starch. The selected isolate, Bacillus subtlis CB-18 was grown in different media at alkaline pH to evaluate the influence of media composition on alkaline α-amylase production. Enzyme assay was carried out by growing the culture in a broth medium and obtaining cell - free culture supernatant after centrifugation at 2515 × g for 15 minutes Amylase activity was determined by incubating 0.5 ml of crude enzyme solution in 0.1M Tris/HCl buffer (pH 8.5) with 0.5 ml of 1% soluble starch solution. The reaction was terminated by the addition of DNS reagent and reducing sugar produced from the amylolytic reaction was determined. Bacillus subtilis CB-18 used for this work was selected because it produced 7 mm zone diameter on starch agar plate. This organism was cultured in different alkaline broth media containing 2% soluble starch as inducer carbohydrate for α-amylase production. Among the carbon sources used for enzyme production, sorbitol was the best to stimulate enzyme production with α-amylase

Sugarcane starch: quantitative determination and characterization

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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.

Some characteristics of a raw starch digestion inhibitory factor from Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Towprayoon, S.; Saha, B.C.; Fujio, Yusaku; Ueda, Seinosuke

1988-09-01

The effect of an inhibitory factor (IF) from Aspergillus niger 19 on raw starch digestion by pure glucoamylase I of black Aspergillus, pure glucoamylase of Rhizopus niveus, bacterial ..cap alpha..-amylase, fungal ..cap alpha..-amylase and various combination was investigated. The IF caused higher inhibition of raw starch hydrolysis by the combined action of glucoamylase and fungal ..cap alpha..-amylase than of hydrolysis by the individual enzymes. A protein moiety of IF might play an active part in this inhibition phenomenon. The IF was found to starch granules, preventing hydrolysis by the enzymes, and caused decreased raw starch hydrolysis yields.

Effect of diluting starch mixtures with bacterial amylase on the heat treatment of the grain

Energy Technology Data Exchange (ETDEWEB)

Ustinikov, B A; Gromov, S I; Poluyanova, M T

1971-01-01

A higher yield of alcohol can be obtained from finely ground grain by diluting the mixtures prior to boiling down with amylolyic enzymes or acids, using thermophilic bacteria. Bacterium diastaticus can withstand temperature as high as 90 to 95/sup 0/C. Experiments are described for studying the effect of time and temperature of boiling on ground grain of different particle size, and of preliminary dilution of the mashes with bacterial amylase. The particle sizes used in the experiment were 0.7 to 1, 1.5 to 2 and 2.5 to 3 mm. The 40 g samples were diluted with 140 ml water and 2 vol % liquid bacterial diastaticus culture with an activity of 160 units/100 ml. 40 minutes on a water bath caused gelation of the starch. Following this treatment, the samples were autoclaved for 10 to 120 minutes at 133, 141, 151 and 158/sup 0/C. Results, expressed in graph form, show that addition of bacterial amylase enabled the grain mash boiling period to be shortened.

A high yield of amylase from Aspergillus niger by the effect of gamma irradiation

International Nuclear Information System (INIS)

El-Saadany, R.M.A.; Salem, F.A.; El-Manawaty, H.K.

1984-01-01

When irradiated rice was used as a media for Aspergillus niger a noticeable increase of amylase production was observed. Molecular degradation of starch molecules did occure, and an increase in starch acidity and solubility was noticed, whereas a marked decrease in viscosity as well as swelling capacity was observed. Gelatinization time and temperature of irradiated starch became shorter or lower resp. These results showed that internal changes in irradiated starch molecules and an alteration in its molecular configuration occured. They may affect the pathway of the growth of the fungi Aspergillus niger. When the amount of amylase was determined by measuring enzyme activity, it was observed that amylases in the irradiated media were higher than in the control media. (orig.) [de

Effects of a dietary Aspergillus oryzae extract containing alpha-amylase activity on performance and carcass characteristics of finishing beef cattle.

Science.gov (United States)

Tricarico, J M; Abney, M D; Galyean, M L; Rivera, J D; Hanson, K C; McLeod, K R; Harmon, D L

2007-03-01

Three experiments were conducted to examine the effects of an Aspergillus oryzae extract containing alpha-amylase activity on performance and carcass characteristics of finishing beef cattle. In Exp. 1, 120 crossbred steers were used in a randomized complete block design to evaluate the effects of roughage source (alfalfa hay vs. cottonseed hulls) and supplemental alpha-amylase at 950 dextrinizing units (DU)/kg of DM. Significant roughage source x alpha-amylase interactions (P < 0.05) were observed for performance. In steers fed cottonseed hulls, supplemental alpha-amylase increased ADG through d 28 and 112 and tended (P < 0.15) to increase ADG in all other periods. The increases in ADG were related to increased DMI and efficiency of gain during the initial 28-d period but were primarily related to increased DMI as the feeding period progressed. Supplemental alpha-amylase increased (P = 0.02) the LM area across both roughage sources. In Exp. 2, 96 crossbred heifers were used in a randomized complete block design with a 2 x 3 factorial arrangement of treatments to evaluate the effects of corn processing (dry cracked vs. high moisture) and supplemental alpha-amylase concentration (0, 580, or 1,160 DU/kg of DM). Alpha-amylase supplementation increased DMI (P = 0.05) and ADG (P = 0.03) during the initial 28 d on feed and carcass-adjusted ADG (P = 0.04) across corn processing methods. Longissimus muscle area was greatest (quadratic effect, P = 0.04), and yield grade was least (quadratic effect, P = 0.02) in heifers fed 580 DU of alpha-amylase/kg of DM across corn processing methods. In Exp. 3, 56 crossbred steers were used in a randomized complete block design to evaluate the effects of supplemental alpha-amylase (930 DU/kg of DM) on performance when DMI was restricted to yield a programmed ADG. Alpha-amylase supplementation did not affect performance when DMI was restricted. We conclude that dietary alpha-amylase supplementation of finishing beef diets may result in

β-Glucans and Resistant Starch Alter the Fermentation of Recalcitrant Fibers in Growing Pigs.

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Sonja de Vries

Full Text Available Interactions among dietary ingredients are often assumed non-existent when evaluating the nutritive value and health effects of dietary fiber. Specific fibers can distinctly affect digestive processes; therefore, digestibility and fermentability of the complete diet may depend on fiber types present. This study aimed to evaluate the effects of readily fermentable fibers (β-glucans and resistant starch on the degradation of feed ingredients containing more persistent, recalcitrant, fibers. Six semi-synthetic diets with recalcitrant fibers from rapeseed meal (pectic polysaccharides, xyloglucans, and cellulose or corn distillers dried grain with solubles (DDGS; (glucuronoarabinoxylans and cellulose with or without inclusion of β-glucans (6% or retrograded tapioca (40% substituted for corn starch were formulated. Six ileal-cannulated pigs (BW 28±1.4 kg were assigned to the diets according to a 6×6 Latin square. β-glucan-extract increased apparent total tract digestibility (ATTD of non-glucosyl polysaccharides (accounting for ~40% of the fiber-fraction from rapeseed meal (6%-units, P10%-units, P<0.001, indicating that the large amount of resistant starch entering the hindgut was preferentially degraded over recalcitrant fibers from rapeseed meal and DDGS, possibly related to reduced hindgut-retention time following the increased intestinal bulk. Fermentation of fiber sources was not only dependent on fiber characteristics, but also on the presence of other fibers in the diet. Hence, interactions in the gastrointestinal tract among fibrous feed ingredients should be considered when evaluating their nutritive value.

Activity and storage of commercial amylases in the 2013 Louisiana grinding season

Science.gov (United States)

A current problem in the application of amylases at sugarcane factories is the existence of a wide variation in the activities and activity per unit cost of commercial amylases. The efficiency of amylase action to break down starch in the factory is related to the activity of the amylase used. Until...

Purification and medium optimization of α-amylase from Bacillus ...

African Journals Online (AJOL)

α-Amylase was first time isolated and purified from Bacillus subtilis 168 (1A1). Purified α-amylase fraction showed a single protein band with a molecular weight of 55 kD. Chemical characterization of the purified α-amylase revealed optimum amylolytic activity at 37°C and pH 7.0 using starch as substrate. It was stable at pH ...

Degradation of the starch components amylopectin and amylose by barley α-amylase 1: Role of surface binding site 2

DEFF Research Database (Denmark)

Nielsen, Jonas Willum; Kramhøft, Birte; Bozonnet, Sophie

2012-01-01

Barley α-amylase isozyme 1 (AMY1, EC 3.2.1.1) contains two surface binding sites, SBS1 and SBS2, involved in the degradation of starch granules. The distinct role of SBS1 and SBS2 remains to be fully understood. Mutational analysis of Tyr-380 situated at SBS2 previously revealed that Tyr-380...... is required for binding of the amylose helix mimic, β-cyclodextrin. Also, mutant enzymes altered at position 380 displayed reduced binding to starch granules. Similarly, binding of wild type AMY1 to starch granules was suppressed in the presence of β-cyclodextrin. We investigated the role of SBS2 by comparing...... kinetic properties of the wild type AMY1 and the Y380A mutant enzyme in hydrolysis of amylopectin, amylose and β-limit dextrin, and the inhibition by β-cyclodextrin. Progress curves of the release of reducing ends revealed a bi-exponential hydrolysis of amylopectin and β-limit dextrin, whereas hydrolysis...

In vitro binding of puroindolines to wheat starch granules

DEFF Research Database (Denmark)

Sørensen, Helle Aagaard; Darlington, H.F.; Shewry, P.R.

2001-01-01

Puroindoline (pin) preparations made from flours of hard and soft wheats contained a mixture of pin-a, 0.19/0.53 alpha -amylase inhibitor, and purothionins. Starch granule preparations from the same cultivars were treated with proteinase to remove surface proteins and incubated with solutions...... of the pin preparations. Binding of pin-a and purothionins but not the 0.19/0.53 inhibitor was observed with no apparent differences between the behavior of the pin preparations or starch granule preparations from hard or soft types. No binding was observed when several other proteins (bovine serum albumin......, total albumins, a commercial preparation of wheat alpha -amylase inhibitors, and barley beta -amylase) were incubated with the starch granules under the same conditions, indicating that in vitro binding can be used to study specific starch granule and protein interactions....

Determination of amylase activity of crude extract from partially ...

African Journals Online (AJOL)

STORAGESEVER

2009-07-20

Jul 20, 2009 ... by its ability to gradually decrease the concentration of the starch solution used as substrate. The optimum ... synthesized during seed germination to mobilize stored food (starch .... basic property of all enzymes and is probably due to concomitant ... Use of potato starch as substrate for β-amylase by Bacillus ...

Amylase Production from Thermophilic Bacillus sp. BCC 021-50 Isolated from a Marine Environment

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Altaf Ahmed Simair

2017-06-01

Full Text Available The high cost of fermentation media is one of the technical barriers in amylase production from microbial sources. Amylase is used in several industrial processes or industries, for example, in the food industry, the saccharification of starchy materials, and in the detergent and textile industry. In this study, marine microorganisms were isolated to identify unique amylase-producing microbes in starch agar medium. More than 50 bacterial strains with positive amylase activity, isolated from marine water and soil, were screened for amylase production in starch agar medium. Bacillus sp. BCC 021-50 was found to be the best amylase-producing strain in starch agar medium and under submerged fermentation conditions. Next, fermentation conditions were optimized for bacterial growth and enzyme production. The highest amylase concentration of 5211 U/mL was obtained after 36 h of incubation at 50 °C, pH 8.0, using 20 g/L molasses as an energy source and 10 g/L peptone as a nitrogen source. From an application perspective, crude amylase was characterized in terms of temperature and pH. Maximum amylase activity was noted at 70 °C and pH 7.50. However, our results show clear advantages for enzyme stability in alkaline pH, high-temperature, and stability in the presence of surfactant, oxidizing, and bleaching agents. This research contributes towards the development of an economical amylase production process using agro-industrial residues.

The effect of carbohydrates on alpha-amylase activity measurements

NARCIS (Netherlands)

Baks, T.; Janssen, A.E.M.; Boom, R.M.

2006-01-01

The Ceralpha method can be used for ¿-amylase activity measurements during the hydrolysis of starch at high substrate concentrations (>40 wt.%). However, the results are affected by the carbohydrates present in the samples. The effect of carbohydrates on the Ceralpha ¿-amylase activity

Arabidopsis thaliana AMY3 Is a Unique Redox-regulated Chloroplastic α-Amylase

DEFF Research Database (Denmark)

Seung, David; Thalmann, Matthias; Sparla, Francesca

2013-01-01

α-Amylases are glucan hydrolases that cleave α-1,4-glucosidic bonds in starch. In vascular plants, α-amylases can be classified into three subfamilies. Arabidopsis has one member of each subfamily. Among them, only AtAMY3 is localized in the chloroplast. We expressed and purified AtAMY3 from...... to be dependent on a conserved aspartic acid residue (Asp666), identified as the catalytic nucleophile in other plant α-amylases such as the barley AMY1. AtAMY3 released small linear and branched glucans from Arabidopsis starch granules, and the proportion of branched glucans increased after the predigestion...

Physicochemical properties and starch digestibility of Chinese noodles in relation to optimal cooking time.

Science.gov (United States)

Ye, Xiaoting; Sui, Zhongquan

2016-03-01

Changes in the physicochemical properties and starch digestibility of white salted noodles (WSN) at different cooking stage were investigated. The noodles were dried in fresh air and then cooked for 2-12 min by boiling in distilled water to determine the properties of cooking quality, textural properties and optical characteristic. For starch digestibility, dry noodles were milled and sieved into various particle size classes ranging from 0.5 mm to 5.0 mm, and hydrolyzed by porcine pancreatic α-amylase. The optimal cooking time of WSN determined by squeezing between glasses was 6 min. The results showed that the kinetics of solvation of starch and protein molecules were responsible for changes of the physicochemical properties of WSN during cooking. The susceptibility of starch to α-amylase was influenced by the cooking time, particle size and enzyme treatment. The greater value of rapidly digestible starch (RDS) and lower value of slowly digestible starch (SDS) and resistant starch (RS) were reached at the optimal cooking stage ranging between 63.14-71.97%, 2.47-10.74% and 23.94-26.88%, respectively, indicating the susceptibility on hydrolysis by enzyme was important in defining the cooked stage. The study suggested that cooking quality and digestibility were not correlated but the texture greatly controls the digestibility of the noodles. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of potato fiber and potato-resistant starch on biomarkers of colonic health in rats fed diets containing red meat.

Science.gov (United States)

Paturi, Gunaranjan; Nyanhanda, Tafadzwa; Butts, Christine A; Herath, Thanuja D; Monro, John A; Ansell, Juliet

2012-10-01

The effects of red meat consumption with and without fermentable carbohydrates on indices of large bowel health in rats were examined. Sprague-Dawley rats were fed cellulose, potato fiber, or potato-resistant starch diets containing 12% casein for 2 wk, then similar diets containing 25% cooked beef for 6 wk. After week 8, cecal and colonic microbiota composition, fermentation end-products, colon structure, and colonocyte DNA damage were analyzed. Rats fed potato fiber had lower Bacteroides-Prevotella-Porphyromonas group compared to other diet groups. Colonic Bifidobacterium spp. and/or Lactobacillus spp. were higher in potato fiber and potato-resistant starch diets than in the cellulose diet. Beneficial changes were observed in short-chain fatty acid concentrations (acetic, butyric, and propionic acids) in rats fed potato fiber compared with rats fed cellulose. Phenol and p-cresol concentrations were lower in the cecum and colon of rats fed potato fiber. An increase in goblet cells per crypt and longer crypts were found in the colon of rats fed potato fiber and potato-resistant starch diets. Fermentable carbohydrates had no effect on colonic DNA damage. Dietary combinations of red meat with potato fiber or potato-resistant starch have distinctive effects in the large bowel. Future studies are essential to examine the efficacy of different types of nondigestible carbohydrates in maintaining colonic health during long-term consumption of high-protein diets. Improved understanding of interactions between the food consumed and gut microbiota provides knowledge needed to make healthier food choices for large bowel health. The impact of red meat on large bowel health may be ameliorated by consuming with fermentable dietary fiber, a colonic energy source that produces less harmful by-products than the microbial breakdown of colonic protein for energy. Developing functional red meat products with fermentable dietary fiber could be one way to promote a healthy and balanced

Calcium or resistant starch does not affect colonic epithelial cell proliferation throughout the colon in adenoma patients : A randomized controlled trial

NARCIS (Netherlands)

van Gorkom, Britta A P; Karrenbeld, Arend; van der Sluis, Tineke; Zwart, Nynke; van der Meer, Roelof; de Vries, Elisabeth G E; Kleibeuker, Jan H

2002-01-01

Patients with a history of sporadic adenomas have increased epithelial cell proliferative activity, an intermediate risk marker for colorectal cancer. Reduction of proliferation by dietary intervention may reflect a decreased colorectal cancer risk. To evaluate whether calcium or resistant starch

Two Strategies for Microbial Production of an Industrial Enzyme-Alpha-Amylase

Science.gov (United States)

Bernhardsdotter, Eva C. M. J.; Garriott, Owen; Pusey, Marc L.; Ng, Joseph D.

2003-01-01

Extremophiles are microorganisms that thrive in, from an anthropocentric view, extreme environments including hot springs, soda lakes and arctic water. This ability of survival at extreme conditions has rendered extremophiles to be of interest in astrobiology, evolutionary biology as well as in industrial applications. Of particular interest to the biotechnology industry are the biological catalysts of the extremophiles, the extremozymes, whose unique stabilities at extreme conditions make them potential sources of novel enzymes in industrial applications. There are two major approaches to microbial enzyme production. This entails enzyme isolation directly from the natural host or creating a recombinant expression system whereby the targeted enzyme can be overexpressed in a mesophilic host. We are employing both methods in the effort to produce alpha-amylases from a hyperthermophilic archaeon (Thermococcus) isolated from a hydrothermal vent in the Atlantic Ocean, as well as from alkaliphilic bacteria (Bacillus) isolated from a soda lake in Tanzania. Alpha-amylases catalyze the hydrolysis of internal alpha-1,4-glycosidic linkages in starch to produce smaller sugars. Thermostable alpha-amylases are used in the liquefaction of starch for production of fructose and glucose syrups, whereas alpha-amylases stable at high pH have potential as detergent additives. The alpha-amylase encoding gene from Thermococcus was PCR amplified using carefully designed primers and analyzed using bioinformatics tools such as BLAST and Multiple Sequence Alignment for cloning and expression in E.coli. Four strains of Bacillus were grown in alkaline starch-enriched medium of which the culture supernatant was used as enzyme source. Amylolytic activity was detected using the starch-iodine method.

High Temperature-Induced Expression of Rice α-Amylases in Developing Endosperm Produces Chalky Grains

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Masaru Nakata

2017-12-01

Full Text Available Global warming impairs grain filling in rice and reduces starch accumulation in the endosperm, leading to chalky-appearing grains, which damages their market value. We found previously that high temperature-induced expression of starch-lytic α-amylases during ripening is crucial for grain chalkiness. Because the rice genome carries at least eight functional α-amylase genes, identification of the α-amylase(s that contribute most strongly to the production of chalky grains could accelerate efficient breeding. To identify α-amylase genes responsible for the production of chalky grains, we characterized the histological expression pattern of eight α-amylase genes and the influences of their overexpression on grain appearance and carbohydrate components through a series of experiments with transgenic rice plants. The promoter activity of most α-amylase genes was elevated to various extents at high temperature. Among them, the expression of Amy1A and Amy3C was induced in the internal, especially basal to dorsal, region of developing endosperm, whereas that of Amy3D was confined near the ventral aleurone. These regions coincided with the site of occurrence of chalkiness, which was in clear contrast to conventionally known expression patterns of the enzyme in the scutellum and aleurone during seed germination. Furthermore, overexpression of α-amylase genes, except for Amy3E, in developing endosperm produced various degrees of chalky grains without heat exposure, whereas that of Amy3E yielded normal translucent grains, as was the case in the vector control, even though Amy3E-overexpressing grains contained enhanced α-amylase activities. The weight of the chalky grains was decreased due to reduced amounts of starch, and microscopic observation of the chalky part of these grains revealed that their endosperm consisted of loosely packed round starch granules that had numerous pits on their surface, confirming the hydrolysis of the starch reserve by

Effects of Arabinoxylan and Resistant Starch on Intestinal Microbiota and Short-Chain Fatty Acids in Subjects with Metabolic Syndrome: A Randomised Crossover Study

DEFF Research Database (Denmark)

Hald, Stine; Schioldan, Anne Grethe; Moore, Mary E

2016-01-01

with two different dietary fibres, arabinoxylan and resistant starch type 2, on the gut microbiome and faecal short-chain fatty acids. Nineteen adults with metabolic syndrome completed this randomised crossover study with two 4-week interventions of a diet enriched with arabinoxylan and resistant starch......Recently, the intestinal microbiota has been emphasised as an important contributor to the development of metabolic syndrome. Dietary fibre may exert beneficial effects through modulation of the intestinal microbiota and metabolic end products. We investigated the effects of a diet enriched...... and a low-fibre Western-style diet. Faecal samples were collected before and at the end of the interventions for fermentative end-product analysis and 16S ribosomal RNA bacterial gene amplification for identification of bacterial taxa. Faecal carbohydrate residues were used to verify compliance. The diet...

α-amylase assay and action pattern determination using radioactive substrate, HPLC, and a radioactive flow detector

International Nuclear Information System (INIS)

Marsili, R.T.; Ostapenko, H.

1987-01-01

A new assay system is presented for the analysis of α-amylase. The disappearance of 14 C-labeled starch substrate and the appearance of its radioactive degradation products were monitored by HPLC and a radioactive flow detector/integrator. The hydrolysis of radioactive substrate was proportional to enzyme concentration when two commercially available α-amylase preparations of Bacillus subtilis origin were studied. The method demonstrated an average recovery of 101.7 +/- 6.5% when modified food starch was spiked with amylase and analyzed. In addition, the method was shown to be useful for predicting detailed action patterns of various types of amylases

Enzymatic degradation behavior and cytocompatibility of silk fibroin-starch-chitosan conjugate membranes

Energy Technology Data Exchange (ETDEWEB)

Baran, Erkan T., E-mail: erkantur@metu.edu.tr; Tuzlakoglu, Kadriye, E-mail: kadriye@dep.uminho.pt; Mano, Joao F., E-mail: jmano@dep.uminho.pt; Reis, Rui L., E-mail: rgreis@dep.uminho.pt

2012-08-01

The objective of this study was to investigate the influence of silk fibroin and oxidized starch conjugation on the enzymatic degradation behavior and the cytocompatability of chitosan based biomaterials. The tensile stress of conjugate membranes, which was at 50 Megapascal (MPa) for the lowest fibroin and starch composition (10 weight percent (wt.%)), was decreased significantly with the increased content of fibroin and starch. The weight loss of conjugates in {alpha}-amylase was more notable when the starch concentration was the highest at 30 wt.%. The conjugates were resistant to the degradation by protease and lysozyme except for the conjugates with the lowest starch concentration. After 10 days of cell culture, the proliferation of osteoblast-like cells (SaOS-2) was stimulated significantly by higher fibroin compositions and the DNA synthesis on the conjugate with the highest fibroin (30 wt.%) was about two times more compared to the native chitosan. The light microscopy and the image analysis results showed that the cell area and the lengths were decreased significantly with higher fibroin/chitosan ratio. The study proved that the conjugation of fibroin and starch with the chitosan based biomaterials by the use of non-toxic reductive alkylation crosslinking significantly improved the cytocompatibility and modulated the biodegradation, respectively. - Highlights: Black-Right-Pointing-Pointer Silk fibroin, starch and chitosan conjugates were prepared by reductive alkylation. Black-Right-Pointing-Pointer The enzymatic biodegradation and the cytocompatibility of conjugates were tested. Black-Right-Pointing-Pointer The conjugate with 30% starch composition was degraded by {alpha}-amylase significantly. Black-Right-Pointing-Pointer Higher starch composition in conjugates prevented protease and lysozyme degradation. Black-Right-Pointing-Pointer Fibroin incorporation effectively increased the cell proliferation of conjugates.

Multi-objective optimization of bioethanol production during cold enzyme starch hydrolysis in very high gravity cassava mash.

Science.gov (United States)

Yingling, Bao; Li, Chen; Honglin, Wang; Xiwen, Yu; Zongcheng, Yan

2011-09-01

Cold enzymatic hydrolysis conditions for bioethanol production were optimized using multi-objective optimization. Response surface methodology was used to optimize the effects of α-amylase, glucoamylase, liquefaction temperature and liquefaction time on S. cerevisiae biomass, ethanol concentration and starch utilization ratio. The optimum hydrolysis conditions were: 224 IU/g(starch) α-amylase, 694 IU/g(starch) glucoamylase, 77°C and 104 min for biomass; 264 IU/g(starch) α-amylase, 392 IU/g(starch) glucoamylase, 60°C and 85 min for ethanol concentration; 214 IU/g(starch) α-amylase, 398 IU/g(starch) glucoamylase, 79°C and 117 min for starch utilization ratio. The hydrolysis conditions were subsequently evaluated by multi-objectives optimization utilizing the weighted coefficient methods. The Pareto solutions for biomass (3.655-4.380×10(8)cells/ml), ethanol concentration (15.96-18.25 wt.%) and starch utilization ratio (92.50-94.64%) were obtained. The optimized conditions were shown to be feasible and reliable through verification tests. This kind of multi-objective optimization is of potential importance in industrial bioethanol production. Copyright © 2011 Elsevier Ltd. All rights reserved.

Physical and catalytic properties of alpha-amylase from Tenebrio molitor L. larvae.

Science.gov (United States)

Buonocore, V; Poerio, E; Silano, V; Tomasi, M

1976-01-01

The amylase from Tenebrio molitor L. larvae (yellow mealworm) was characterized according to a number of its molecular and catalytic properties. The insect amylase is a single polypeptide chain with mol.wt. 68000, an isoelectric point of 4.0 and a very low content of sulphur-containing amino acids. The enzyme is a Ca2+-protein and behaves as an alpha-amylase. Removal of Ca2+ by exhaustive dialysis against water causes the irreversible inactivation of the enzyme. Moreover, the enzyme is activated by the presence in the assay mixture of Cl-, or some other inorganic anions that are less effective than Cl-, and is inhibited by F-. Optimal conditions of pH and temperature for the enzymic activity are 5.8 and 37 degrees C. The insect amylase exhibits an identical kinetic behaviour toward starch, amylose and amylopectin; the enzyme hydrolyses glycogen with a higher affinity constant. Compared with the non-insect alpha-amylases described in the literature, Tenebrio molitor amylase has a lower affinity for starch. PMID:942374

Use of biomass energy. Saccharification of raw starch and ethanol fermentation

Energy Technology Data Exchange (ETDEWEB)

Ueda, S

1982-01-01

Raw starch was saccharified under acidic condition of pH 3.5 using black-koji amylase, and the resultant saccharidies were fermented to give ethanol in succession. White polished rice flour was fermented at 30 degrees C during the period of 7 to 10 days to give ethanol. Semi-continuous ethanol fermentation was carried out using corn starch and cassava starch. Batch ethanol fermentation was also carried out using cassava or sweet potato. Sweet potato was fermented using Rhizopus gluco-amylase. 11 references.

Enhancement of amylase production by Aspergillus sp. using carbohydrates mixtures from triticale

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Dojnov Biljana

2015-01-01

Full Text Available For the purpose of finding a suitable available inducer in combination with starvation, carbohydrate mixtures from triticale was used as inducers and compared with well-known amylase inducers in fungi. Carbohydrate mixtures from triticale induced production of amylase cocktail (α-amylase and glucoamylase in Aspergillus niger, unlike induction with well-known inducers which induce only glucoamylase, showed by zymogram and TLC analysis of carbohydrates mixtures before and after fermentations. Glucoamylase production by A. niger was highest in the presence of extract obtained after autohydrolysis of starch from triticale (95.88 U/mL. Carbohydrate mixtures from triticale induced production of α-amylase in A. oryzae. More α-amylase isoforms were detected upon using complex carbohydrate mixture, compared to induction with maltose or starch. The 48 h induction was the most efficient by using triticale extract (101.35 U/mL. Carbohydrates from triticale extracts can be used as very good cheap amylase inducers. Triticale, still not fully utilized, could be taken into consideration as the inducer in amylase production by Aspergillus sp, such a way it could be used as sole substrate in fermentation. [Projekat Ministarstva nauke Republike Srbije, br. 172048

Isolation of α-amylase from malted rice (Wita 7) extract using ...

African Journals Online (AJOL)

user

microbial α-amylase enzymes has led to the studies in cereal malting (Hammond ... beta amylase and other starch degrading enzymes lead to an absolute ... water in a plastic container at a temperature of 28±1°C for 24 h. The soaked grains ...

Effect of dietary starch source on milk production and composition of ...

African Journals Online (AJOL)

huis

The larger granules of more enzyme-resistant B-type crystalline starch in ... of nonstructural carbohydrates increases the utilization of ruminal ammonia-N ..... An improved enzymatic method for the determination of native and modified starch. J.

Effect of dietary carbohydrate on non-specific immune response, hepatic antioxidative abilities and disease resistance of juvenile golden pompano (Trachinotus ovatus).

Science.gov (United States)

Zhou, Chuanpeng; Ge, Xianping; Lin, Heizhao; Niu, Jin

2014-12-01

The present study was conducted to investigate the effects of dietary carbohydrate (CHO) levels on non-specific immune responses, hepatic antioxidative status and disease resistance of juvenile golden pompano. Fish were fed six isonitrogenous and isoenergetic diets containing various CHO levels for 8 weeks. After the feeding trial, fish were challenged by Vibrio harveyi and survival rate was recorded for the next 12 days. Plasma total protein and albumin content, respiratory burst activity, alkaline phosphatase, slightly increased with dietary starch level from 0% to 16.8%, but significantly decreased at dietary starch levels of 16.8%-28%. Plasma lysozyme, complement 3 and complement 4 levels increased with increasing dietary carbohydrate up to 11.2% and then declined (P 0.05) with those of the other treatments. After challenge, fish fed 11.2% and 16.8% dietary CHO showed higher survival rate than that of fish in 0% CHO group (P 0.05). The results of this study suggest that ingestion of 11.2-16.8% dietary CHO can enhance the non-specific immune responses, increase the hepatic antioxidant abilities, and improve resistance to V. harveyi infection of juvenile golden pompano. Copyright © 2014 Elsevier Ltd. All rights reserved.

Unexpected High Digestion Rate of Cooked Starch by the Ct-Maltase-Glucoamylase Small Intestine Mucosal α-Glucosidase Subunit

Science.gov (United States)

Lin, Amy Hui-Mei; Nichols, Buford L.; Quezada-Calvillo, Roberto; Avery, Stephen E.; Sim, Lyann; Rose, David R.; Naim, Hassan Y.; Hamaker, Bruce R.

2012-01-01

For starch digestion to glucose, two luminal α-amylases and four gut mucosal α-glucosidase subunits are employed. The aim of this research was to investigate, for the first time, direct digestion capability of individual mucosal α-glucosidases on cooked (gelatinized) starch. Gelatinized normal maize starch was digested with N- and C-terminal subunits of recombinant mammalian maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) of varying amounts and digestion periods. Without the aid of α-amylase, Ct-MGAM demonstrated an unexpected rapid and high digestion degree near 80%, while other subunits showed 20 to 30% digestion. These findings suggest that Ct-MGAM assists α-amylase in digesting starch molecules and potentially may compensate for developmental or pathological amylase deficiencies. PMID:22563462

Effects of germination on the activities of amylases and phenolic enzymes in sorghum varieties grouped according to food end-use properties

NARCIS (Netherlands)

Dicko, M.H.; Gruppen, H.; Zouzouho, O.C.; Traore, A.S.; Berkel, van W.J.H.; Voragen, A.G.J.

2006-01-01

Fifty sorghum varieties were screened to determine the effects of germination on levels of starch, -amylase, -amylase, phenylalanine ammonia lyase (PAL), peroxidase (POX) and polyphenol oxidase (PPO). Germination decreased starch content, with amylose being more degraded than amylopectin. In

Dynamic moisture sorption characteristics of enzyme-resistant recrystallized cassava starch.

Science.gov (United States)

Mutungi, Christopher; Schuldt, Stefan; Onyango, Calvin; Schneider, Yvonne; Jaros, Doris; Rohm, Harald

2011-03-14

The interaction of moisture with enzyme-resistant recrystallized starch, prepared by heat-moisture treatment of debranched acid-modified or debranched non-acid-modified cassava starch, was investigated in comparison with the native granules. Crystallinities of the powdered products were estimated by X-ray diffraction. Moisture sorption was determined using dynamic vapor sorption analyzer and data fitted to various models. Percent crystallinities of native starch (NS), non-acid-modified recrystallized starch (NAMRS), and acid-modified recrystallized starch (AMRS) were 39.7, 51.9, and 56.1%, respectively. In a(w) below 0.8, sorption decreased in the order NS > NAMRS > AMRS in line with increasing sample crystallinities but did not follow this crystallinity dependence at higher a(w) because of condensation and polymer dissolution effects. Adsorbed moisture became internally absorbed in NS but not in NAMRS and AMRS, which might explain the high resistance of the recrystallized starches to digestion because enzyme and starch cannot approach each other over fairly sufficient surface at the molecular level.

Dietary sucrose and starch affect dysplastic characteristics in carcinogen-induced aberrant crypt foci in rat colon.

Science.gov (United States)

Caderni, G; Lancioni, L; Luceri, C; Giannini, A; Lodovici, M; Biggeri, A; Dolara, P

1997-03-19

To study whether dietary carbohydrates affect dysplasia in aberrant crypt foci (ACF), rats treated with 1,2-dimethilhydrazine (DMH) were fed for three months with diets containing 46% sucrose or corn starch. The number of ACF/colon in the two dietary groups was similar (P = 0.58), but ACF were smaller in the starch than in sucrose group (P colon carcinogenesis while sucrose in the diet is detrimental, promoting the dysplasia of preneoplastic lesions like ACF.

Improved method for measurement of dietary fiber as non-starch polysaccharides in plant foods.

Science.gov (United States)

Englyst, H N; Cummings, J H

1988-01-01

A method is described that allows rapid estimation of total, soluble, and insoluble dietary fiber as the non-starch polysaccharides (NSP) in plant foods. It is a modification of an earlier, more complex procedure. Starch is completely removed enzymatically, and NSP is measured as the sum of its constituent sugars released by acid hydrolysis. The sugars may, in turn, be measured by gas chromatography (GC), giving values for individual monosaccharides, or more rapidly by colorimetry. Both GC and colorimetry are suitable for routine measurement of total, soluble, and insoluble dietary fiber in cereals, fruits, and vegetables. Values obtained are not affected by food processing so the dietary fiber content of various processed foods and mixed diets can be calculated simply from knowing the amount in the raw materials. The additional information obtained by GC analysis is valuable in the interpretation of physiological studies and in epidemiology where disease is related to type and amount of dietary fiber.

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...... AM and BE. The molecular analysis of the products including amylopectin chain length distribution, content of α-1,6 glucosidic linkages, absolute molecular weight distribution and digestibility were examined. Only BE catalysis showed 7.8% of branching linkages. The sequential AMBE-treated starch...... showed 9.9%-10.0% branching linkages, while the sequential BEAMBE-treated starch gained 10.9%-13.1% of branching linkages. Moreover, the sequential AMBE and BEAMBE-treated starch retarded the digestion rate of α-amylase and glucoamylase. Overall, sequential BEAMBE catalysis resulted in more...

Molecular improvements in microbial α-amylases for enhanced stability and catalytic efficiency.

Science.gov (United States)

Sindhu, Raveendran; Binod, Parameswaran; Madhavan, Aravind; Beevi, Ummalyma Sabeela; Mathew, Anil Kuruvilla; Abraham, Amith; Pandey, Ashok; Kumar, Vinod

2017-12-01

α-Amylases is one of the most important industrial enzyme which contributes to 25% of the industrial enzyme market. Though it is produced by plant, animals and microbial source, those from microbial source seems to have potential applications due to their stability and economic viability. However a large number of α-amylases from different sources have been detailed in the literature, only few numbers of them could withstand the harsh industrial conditions. Thermo-stability, pH tolerance, calcium independency and oxidant stability and starch hydrolyzing efficiency are the crucial qualities for α-amylase in starch based industries. Microbes can be genetically modified and fine tuning can be done for the production of enzymes with desired characteristics for specific applications. This review focuses on the native and recombinant α-amylases from microorganisms, their heterologous production and the recent molecular strategies which help to improve the properties of this industrial enzyme. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of amylases by Aspergillus tamarii

Directory of Open Access Journals (Sweden)

Moreira Fabiana Guillen

1999-01-01

Full Text Available A strain of Aspergillus tamarii, a filamentous fungus isolated from soil, was able to produce both a-amylase and glucoamylase activities in mineral media supplemented with 1% (w/v starch or maltose as the carbon source. Static cultivation led to significantly higher yields than those obtained using shaking culture. The production of amylases was tolerant to a wide range of initial culture pH values (from 4 to 10 and temperature (from 25 to 42oC. Two amylases, one a-amylase and one glucoamylase, were separated by ion exchange chromatography. Both partially purified enzymes had optimal activities at pH values between 4.5 and 6.0 and were stable under acid conditions (pH 4.0-7.0. The enzymes exhibited optimal activities at temperatures between 50o and 60o C and were stable for more than ten hours at 55oC.

Defining Starch Binding by Glucan Phosphatases

DEFF Research Database (Denmark)

Auger, Kyle; Raththagala, Madushi; Wilkens, Casper

2015-01-01

Starch is a vital energy molecule in plants that has a wide variety of uses in industry, such as feedstock for biomaterial processing and biofuel production. Plants employ a three enzyme cyclic process utilizing kinases, amylases, and phosphatases to degrade starch in a diurnal manner. Starch...... is comprised of the branched glucan amylopectin and the more linear glucan amylose. Our lab has determined the first structures of these glucan phosphatases and we have defined their enzymatic action. Despite this progress, we lacked a means to quickly and efficiently quantify starch binding to glucan...

Comparison of some functional properties and chemical constituents ...

African Journals Online (AJOL)

use

2011-12-14

Dec 14, 2011 ... or analogous carbohydrates that are resistant to digestion and absorption in ... rice bran was gelatinized with termamyl (heat stable alpha-amylase) at 100°C for 1 h ... tation was allowed to form at room temperature for 60 min, followed by filtration. ... Ash, protein and starch contents of dietary fibre extracted.

Comparative studies of starch susceptibilities to α-amylase ...

African Journals Online (AJOL)

ayoade

of the four starch samples varied; amylose content of starch from maize varieties was higher than ... plants as an energy store. ... staple foods as potatoes, wheat, maize (corn), rice and ... of its various chemical and physical properties, can be.

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

Directory of Open Access Journals (Sweden)

Jnnifer A. Sánchez

2014-05-01

Full Text Available Bacillus cereus is a food contaminant and a known human pathogen that can cause emetic and diarrheal syndromes. In this study we evaluated the presence of toxigenic B. cereus by multiplex PCR directly in dietary complement for children and cassava starch samples collected on Medellin, Colombia. Of 75 dietary complement for children samples evaluated, 70.7% were contaminated with toxigenic B. cereus and four different toxigenic 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% were contaminated with toxigenic B. cereus and four different toxigenic consortia were determined: 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 only enterotoxigenic consortia were detected while in cassava starch the enterotoxigenic consortia predominated over the emetic. Multiplex PCR was useful to detect toxigenic B. cereus contamination allowing direct and imultaneous detection of all toxin genes in foods. This study is the first in Colombia to evaluate toxigenic B. cereus, providing information of importance for microbiological risk evaluation in dried foods.

Milk glucosidase activity enables suckled pup starch digestion

Science.gov (United States)

Starch requires six enzymes for digestion to free glucose: two amylases (salivary and pancreatic) and four mucosal maltase activities; sucrase-isomaltase and maltase-glucoamylase. All are deficient in suckling rodents. The objective of this study is to test (13)C-starch digestion before weaning by m...

Growth and α-amylase production by strains of Lactobacillus ...

African Journals Online (AJOL)

A cassava starch medium was used to analyse the dynamics of batch growth and α-amylase production of strains of Lactobacillus plantarum and Rhizopus oryzae isolated from cassava dried chips. The strains displayed a growth of 0.5h-1 and 0.55 h-1, a biomass yield on cassava starch of 0.49g/g and 0.5g/g, a maximum ...

Amylolytic hydrolysis of native starch granules affected by granule surface area.

Science.gov (United States)

Kim, J C; Kong, B W; Kim, M J; Lee, S H

2008-11-01

Initial stage of hydrolysis of native starch granules with various amylolytic enzymes, alpha-amylase from Bacillus subtilis, glucoamylase I (GA-I) and II (GA-II) from Aspergillus niger, and beta-amylase from sweet potato showed that the reaction was apparently affected by a specific surface area of the starch granules. The ratios of the reciprocal of initial velocity of each amylolytic hydrolysis for native potato and maize starch to that for rice with the amylolytic enzymes were nearly equivalent to the ratio of surface area per mass of the 2 starch granules to that of rice, that is, 6.94 and 2.25, respectively. Thus, the reciprocal of initial velocity of each enzymatic hydrolysis as expressed in a Lineweaver-Burk plot was a linear function of the reciprocal of surface area for each starch granule. As a result, it is concluded that amylolytic hydrolysis of native starch granules is governed by the specific surface area, not by the mass concentration, of each granule.

Mutational analysis of the β-trefoil fold protein barley α-amylase/subtilisin inhibitor probes hot spots for the interaction with barley α-amylase

DEFF Research Database (Denmark)

Bønsager, Birgit Christine; Nielsen, P. K.; Abou Hachem, Maher

2005-01-01

The barley alpha-amylase/subtilisin inhibitor (BASI) inhibits alpha-amylase 2 (AMY2) with subnanomolar affinity. The contribution of selected side chains of BASI to this high affinity is discerned in this study, and binding to other targets is investigated. Seven BASI residues along the AMY2-BASI...... interface and four residues in the putative protease-binding loop on the opposite side of the inhibitor were mutated. A total of 15 variants were compared with the wild type by monitoring the alpha-amylase and protease inhibitory activities using Blue Starch and azoalbumin, respectively, and the kinetics...

Isolation and characterisation of a novel alpha-amylase from the extreme haloarchaeon Haloterrigena turkmenica.

Science.gov (United States)

Santorelli, Marco; Maurelli, Luisa; Pocsfalvi, Gabriella; Fiume, Immacolata; Squillaci, Giuseppe; La Cara, Francesco; Del Monaco, Giovanni; Morana, Alessandra

2016-11-01

An extracellular halophilic alpha-amylase (AmyA) was produced by the haloarchaeon Haloterrigena turkmenica grown in medium enriched with 0.2% (w/v) starch. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and size exclusion chromatography (SEC) analyses showed a major band at 66.0kDa and a peak of 54.0kDa, respectively. Analysis of tryptic fragments of the protein present in the major SDS-PAGE band by nano-LC-ESI-MS/MS led to identification of the alpha-amylase catalytic region, encoded by the htur2110 gene, as the protein possessing the described activity. Optimal values for activity were 55°C, pH 8.5 and 2M NaCl, and high thermostability was showed at 55°C and 3M NaCl. AmyA activity was enhanced by Triton X-100 and was not influenced by n-hexane and chloroform. Starch hydrolysis produced different oligomers with maltose as the smallest end-product. The efficiency of AmyA in degrading starch contained in agronomic residues was tested in grape cane chosen as model substrate. Preliminary results showed that starch was degraded making the enzyme a potential candidate for utilization of agro-industrial waste in fuel and chemicals production. AmyA is one of the few investigated amylases produced by haloarchaea, and the first alpha-amylase described among microorganisms belonging to the genus Haloterrigena. Copyright © 2016 Elsevier B.V. All rights reserved.

Amylase production under solid state fermentation by a bacterial ...

African Journals Online (AJOL)

SAM

2014-05-21

May 21, 2014 ... Addition of exogenous glucose repressed secretion of amylase, demonstrating that a classical glucose effect ... Enzymatic hydrolysis of starch is carried out under tem- ... thermal springs at Arbaminch, Awassa, Nazreth, Shalla.

Clinical and immunological responses to occupational exposure to alpha-amylase in the baking industry.

OpenAIRE

Brisman, J; Belin, L

1991-01-01

alpha-Amylase is a starch cleaving enzyme often used in the baking industry as a flour additive. It is usually of fungal origin, produced by Aspergillus oryzae. One previous report has shown IgE antibodies and positive skin prick test against alpha-amylase in asthmatic bakers. This paper describes four alpha-amylase sensitised index cases with occupational asthma or rhinitis and the results of a cross sectional study of 20 workers from the same factory who were also exposed to alpha-amylase p...

Digestion of Starch Granules from Maize, Potato and Wheat by Larvae of the the Yellow Mealworm, Tenebrio molitor and the Mexican Bean Weevil, Zabrotes subfasciatus

Science.gov (United States)

Meireles, Elaine A.; Carneiro, Cíntia N. B.; DaMatta, Renato A.; Samuels, Richard I.; Silva, Carlos P.

2009-01-01

Scanning electron microscopy images were taken of starch granules from different sources following exposure in vivo and in vitro to gut α-amylases isolated from Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae). One α-amylase was isolated from whole larval midguts of T. molitor using non-denaturing SDS-PAGE, while two other α-amylase fractions were isolated from whole larval midguts of Z. subfasciatus using hydrophobic interaction chromatography., Digested starch granules from larvae fed on maize, potato or wheat were isolated from midgut contents. Combinations of starch granules with isolated α-amylases from both species showed similar patterns of granule degradation. In vitro enzymatic degradation of maize starch granules by the three different α-amylase fractions began by creating small holes and crater-like areas on the surface of the granules. Over time, these holes increased in number and area resulting in extensive degradation of the granule structure. Granules from potato did not show formation of pits and craters on their surface, but presented extensive erosion in their interior. For all types of starch, as soon as the interior of the starch granule was reached, the inner layers of amylose and amylopectin were differentially hydrolyzed, resulting in a striated pattern. These data support the hypothesis that the pattern of starch degradation depends more on the granule type than on the α-amylase involved. PMID:19619014

α-Amylase production by Penicillium fellutanum isolated from ...

African Journals Online (AJOL)

GRACE

2006-05-16

May 16, 2006 ... products obtained by starch hydrolysis. Since this natural isolate produced low concentration of amylase, attempts were made to increase the productivity by optimizing the cultural conditions. MATERIALS AND METHODS. Microorganism. The fungus, Penicillium fellutanum Biourge., was isolated from.

Isolation of α-amylase from malted rice (Wita 7) extract using ...

African Journals Online (AJOL)

The crude α-amylase from the 8th day malt extract was subsequently purified using starch column procedure. The purified extract recorded an estimated activity of 75.549 U/ml. The project further examined the effects of varying the ratios of starch adsorbent height to column diameter (L/D) during the purification step. For the ...

Production and Partial Purification of Alpha Amylase from Bacillus subtilis (MTCC 121 Using Solid State Fermentation

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Dibyangana Raul

2014-01-01

Full Text Available Amylase is an enzyme that catalyzes the breakdown of starch into sugars and plays a pivotal role in a variety of areas like use as digestives, for the production of ethanol and high fructose corn syrup, detergents, desiring of textiles, modified starches, hydrolysis of oil-field drilling fluids, and paper recycling. In the present work, solid state fermentation (SSF for α-amylase production has been used in lieu of submerged fermentation (SmF due to its simple technique, low capital investment, lower levels of catabolite repression, and better product recovery. Bacillus subtilis has been well known as producer of alpha amylase and was tested using solid state fermentation for 48 hours at 37°C with wheat bran as substrate. Comparison between different fermentation hours demonstrated high yield of alpha amylase after 48 hours. This alpha amylase has optimum pH and temperature at 7.1 and 40°C, respectively. With the goal to purify alpha amylase, 30–70% (NH42SO4 cut concentrated the amylase activity threefold with respect to crude fermented extract. This was verified in quantitative DNS assay method as well as in zymogram gel profile. The exact molecular weight of the amylase is yet to be determined with the aid of other protein purification techniques.

The Effects of Curcumin on Alpha Amylase in Diabetics Rats

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Mahmood Najafian

2015-12-01

Full Text Available Background One of the therapeutic approaches to lower postprandial blood glucose is to inhibition breakdown of starch by inhibiting carbohydrate hydrolysis enzymes. Alpha-amylase catalyzes the hydrolysis of α-(1, 4-D-glycosidic linkages of starch and other glucose polymers. Inhibitors of this enzyme could be used in the treatment of diabetes. Objectives Based on this purpose we examined the effect of curcumin on alpha amylase and its IC50 and Ki. Materials and Methods In this experimental study, 60 rats were divided into two major groups, normal and diabetic, and each was subsequently divided into five subgroups. One of them as control group that received grape seed oil and four of them as experimental groups that received curcumin at 10, 20, 40 and 80 mg/kg (each group include six rats. Blood glucose levels were measured every three days. Serum insulin levels were measured three times, in the first day, middle and end of the experimental period. The activity of serum alpha amylase was measured in the end of experimental period. Results The results showed that curcumin is a competitive inhibitor for alpha amylase with IC50 = 51.32 µM and Ki = 20.17 µM. In both diabetic and normal groups in all doses nearly dose dependent manner reduced blood glucose and insulin levels. In both diabetic and normal groups decreased levels of serum alpha amylase activity. Conclusions It may be concluded that curcumin is a potent inhibitor of alpha amylase and has beneficial effects in the treatment of overweight and diabetes

Deficiency of maize starch-branching enzyme i results in altered starch fine structure, decreased digestibility and reduced coleoptile growth during germination

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Yandeau-Nelson Marna

2011-05-01

Full Text Available Abstract Background Two distinct starch branching enzyme (SBE isoforms predate the divergence of monocots and dicots and have been conserved in plants since then. This strongly suggests that both SBEI and SBEII provide unique selective advantages to plants. However, no phenotype for the SBEI mutation, sbe1a, had been previously observed. To explore this incongruity the objective of the present work was to characterize functional and molecular phenotypes of both sbe1a and wild-type (Wt in the W64A maize inbred line. Results Endosperm starch granules from the sbe1a mutant were more resistant to digestion by pancreatic α-amylase, and the sbe1a mutant starch had an altered branching pattern for amylopectin and amylose. When kernels were germinated, the sbe1a mutant was associated with shorter coleoptile length and higher residual starch content, suggesting that less efficient starch utilization may have impaired growth during germination. Conclusions The present report documents for the first time a molecular phenotype due to the absence of SBEI, and suggests strongly that it is associated with altered physiological function of the starch in vivo. We believe that these results provide a plausible rationale for the conservation of SBEI in plants in both monocots and dicots, as greater seedling vigor would provide an important survival advantage when resources are limited.

Effects of dietary starch and protein levels on milk production and composition of dairy cows fed high concentrate diet

Directory of Open Access Journals (Sweden)

Mustafa Güçlü Sucak

2017-07-01

Full Text Available Abstract Twenty eight Holstein cows (averaged 41±31.5 and 82±24 days in milk, and 30.4±3.49 and 29.0±2.22 kg/d milk yield were fed a high concentrate diet (70:30 concentrate to forage to examine effects on milk production and composition. The cows were randomly assigned to receive four dietary treatments according to a 2 x 2 factorial arrangement. Factors were starch (14% and 22% and protein (15% and 18%. Wheat straw was used as forage source. The study lasted 6 weeks. Dry matter intake was not affected (P> 0.05 by the dietary treatments in the study. Milk yield increased with increased dietary protein level (P< 0.01. Milk urea nitrogen concentrations were affected by dietary protein and starch levels, but there was no interaction effect. Nitrogen efficiency (Milk N/N intake was decreased by increasing in dietary protein level (P< 0.01. In conclusion, the cows fed total mixed ration (TMR containing low level of wheat straw responded better when dietary protein increased. But, efficiency of N use and N excretion to the environment were worsened. Key words: Dairy cattle, milk composition, protein, starch, wheat straw

Isolation, purification and characterization of β-amylase from Dioscorea hispida Dennst

Science.gov (United States)

Oktiarni, Dwita; Lusiana, Simamora, Febri Yanti; Gaol, Jusni M. Lumban

2015-09-01

β-amylase (E.C 3.2.1.2) is an enzyme commonly found in plants and bacteria. The enzyme is an exo-acting carbohydrolase which hydrolyzes α-1.4-glucosidic linkages of starch, removing maltose units from the non-reducing end of the polysaccharide chain, producing β-maltose and β-limit dextrin as the final product. β-amylase is widely distributed in the higher plants such as sweet potato. Besides the use in starch hydrolysis, starch-converting enzymes are also used in a number of other industrial applications, such as laundry and porcelain detergents or as anti-stalling agents in baking. This enzyme was extracted from Dioscorea hispida Dennst in 0.05 M acetate buffer pH 4.8 and followed by ammonium sulfate fractionation at cold temperature (10°C). Ammonium sulfate fractionation was shared into fraction of 0-60%, 60-70%, 70-80% and 80-100%. The fraction containing high of specific activity (determined by Somogyi-Nelson and Lowry methods) was futher purified by dialysis. Fraction with high enzyme activity of β-amylase were fraction 60-70% and 70-80%, with specific activity of Dioscorea hispida Dennst were 1.32 and 1.55 mg sugar.mg protein-1.minute-1, whereas specific activity of crude extract enzyme was 0.21 mg sugar.mg protein-1.minute-1. After purified with dialysis, fraction with high enzyme activity of β-amylase were fraction of 60-70% and 70-80%, with specific activity of Dioscorea hispida Dennst was 2.72 and 4.24 mg sugar.mg protein-1.minute-1. The purified Dioscorea hispida Dennst β-amylase from dialysis showed increasing in spesific activity the crude enzyme as much as 24 folds. The characterization of enzyme showed that Dioscorea hispida Dennst derived enzyme had optimum pH of 5.5 and temperature of 70°C. The kinetic parameters of purified Dioscorea hispida Dennst β-amylase showed that the KMapp, Vmaxapp value and Hill constant were 0.0211 mg/ml, 9.63 mg sugar.minute-1 and 1.34, respectively.

Hydrolysis of maize starch using amylolytic enzymes extracted from ...

African Journals Online (AJOL)

Amylases, a-amylase (EC 3.2.1.1, α-1, 4-glucan-4-glucanohydrolase) and glucoamylase (EC 3.2.1.3, α-1, 4; α-1, 6-glucan glucohydrolase; amyloglucosidase), extracted and partially purified from sorghum malt were used to hydrolyze maize starch. The process and products of the enzymatic hydrolysis were also compared ...

Amylase catalyzed synthesis of glycosyl acrylates and their polymerization

NARCIS (Netherlands)

Kloosterman, Wouter M.J.; Jovanovic, Danijela; Brouwer, Sander; Loos, Katja

2014-01-01

The enzymatic synthesis of novel (di)saccharide acrylates from starch and 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate and 4-hydroxybutyl acrylate (2-HEA, 2-HEMA and 4-HBA) catalyzed by various commercially available amylase preparations is demonstrated. Both liquefaction and

Glycogenesis and de novo lipid synthesis from dietary starch in juvenile gilthead sea bream (Sparus aurata) quantified with stable isotopes

DEFF Research Database (Denmark)

Ekmann, Kim Schøn; Dalsgaard, Anne Johanne Tang; Holm, Jørgen

2013-01-01

the metabolic fate of dietary starch, 0·7% wheat starch was replaced with isotope-labelled starch (.98% 13C). Fish were fed the experimental diets for three consecutive 10 d periods, and isotope ratio MS was applied to quantify 13C enrichment of liver and whole-body glycogen and lipid pools over the three...

A study of the process control and hydrolytic characteristics in a thermophilic hydrogen fermentor fed with starch-rich kitchen waste by using molecular-biological methods and amylase assay

Energy Technology Data Exchange (ETDEWEB)

Wang, Yu-Hsuan; Li, Shiue-Lin; Chen, I.-Chieh; Tseng, I.-Cheng; Cheng, Sheng-Shung [Department of Environmental Engineering, National Cheng Kung University, No. 1, University Road, Tainan 701 (China)

2010-12-15

Starch-rich kitchen waste was chosen as the feedstock in this study, and a 3-L intermittent-continuous stirred tank reactor (I-CSTR) was established. Within 240 days, the maximum average hydrogen production rate of 2.2 L-H{sup 2} L{sup -1} day{sup -1} and the highest average hydrogen yield of 2.1 mmol-H{sub 2} g-COD{sup -1} were both observed in run 3-2, which was operated at an eight-day hydraulic retention time (HRT) and 39 g-COD L{sup -1} day{sup -1} of organic loading rate. According to the analyses of amylase and reducing sugar, the maximum average amylase activity was about 11 U mL{sup -1} in run 1, but the maximum solid carbohydrate hydrolysis rate was about 45% in run 3. Some Michaealis-Menton kinetic parameters, such as K{sub M} (17 g L{sup -1}) and the maximum activity (1.5 U mL{sup -1}) of the amylase were obtained. The best amylase reacting temperature was 55 C, and the best reacting pH was 4.4 tested with acetate buffer. Twenty-seven operational taxonomic units (OTUs) were selected from this reactor by using a cloning method. According to the data of terminal restricted fragment length polymorphism (T-RFLP) and amylase assay, the OTUs that were related to Thermoanaerobacterium thermosaccharolyticum and Clostridium sp. were in direct proportion to the amylase activity. (author)

A thermophilic alkalophilic α-amylase from Bacillus sp. AAH-31 shows a novel domain organization among glycoside hydrolase family 13 enzymes.

Science.gov (United States)

Saburi, Wataru; Morimoto, Naoki; Mukai, Atsushi; Kim, Dae Hoon; Takehana, Toshihiko; Koike, Seiji; Matsui, Hirokazu; Mori, Haruhide

2013-01-01

α-Amylases (EC 3.2.1.1) hydrolyze internal α-1,4-glucosidic linkages of starch and related glucans. Bacillus sp. AAH-31 produces an alkalophilic thermophilic α-amylase (AmyL) of higher molecular mass, 91 kDa, than typical bacterial α-amylases. In this study, the AmyL gene was cloned to determine its primary structure, and the recombinant enzyme, produced in Escherichia coli, was characterized. AmyL shows no hydrolytic activity towards pullulan, but the central region of AmyL (Gly395-Asp684) was similar to neopullulanase-like α-amylases. In contrast to known neopullulanase-like α-amylases, the N-terminal region (Gln29-Phe102) of AmyL was similar to carbohydrate-binding module family 20 (CBM20), which is involved in the binding of enzymes to starch granules. Recombinant AmyL showed more than 95% of its maximum activity in a pH range of 8.2-10.5, and was stable below 65 °C and from pH 6.4 to 11.9. The kcat values for soluble starch, γ-cyclodextrin, and maltotriose were 103 s(-1), 67.6 s(-1), and 5.33 s(-1), respectively, and the Km values were 0.100 mg/mL, 0.348 mM, and 2.06 mM, respectively. Recombinant AmyL did not bind to starch granules. But the substitution of Trp45 and Trp84, conserved in site 1 of CBM20, with Ala reduced affinity to soluble starch, while the mutations did not affect affinity for oligosaccharides. Substitution of Trp61, conserved in site 2 of CBM20, with Ala enhanced hydrolytic activity towards soluble starch, indicating that site 2 of AmyL does not contribute to binding to soluble long-chain substrates.

Investigating the Mechanisms of Amylolysis of Starch Granules by Solution-State NMR

Science.gov (United States)

2015-01-01

Starch is a prominent component of the human diet and is hydrolyzed by α-amylase post-ingestion. Probing the mechanism of this process has proven challenging, due to the intrinsic heterogeneity of individual starch granules. By means of solution-state NMR, we demonstrate that flexible polysaccharide chains protruding from the solvent-exposed surfaces of waxy rice starch granules are highly mobile and that during hydrothermal treatment, when the granules swell, the number of flexible residues on the exposed surfaces increases by a factor of 15. Moreover, we show that these flexible chains are the primary substrates for α-amylase, being cleaved in the initial stages of hydrolysis. These findings allow us to conclude that the quantity of flexible α-glucan chains protruding from the granule surface will greatly influence the rate of energy acquisition from digestion of starch. PMID:25815624

Digestion of isolated legume cells in a stomach-duodenum model: three mechanisms limit starch and protein hydrolysis.

Science.gov (United States)

Bhattarai, Rewati R; Dhital, Sushil; Wu, Peng; Chen, Xiao Dong; Gidley, Michael J

2017-07-19

Retention of intact plant cells to the end of the small intestine leads to transport of entrapped macronutrients such as starch and protein for colonic microbial fermentation, and is a promising mechanism to increase the content of resistant starch in diets. However, the effect of gastro-intestinal bio-mechanical processing on the intactness of plant cells and the subsequent resistance to enzymatic digestion of intracellular starch and protein are not well understood. In this study, intact cells isolated from legume cotyledons are digested in a laboratory model which mimics the mechanical and biochemical conditions of the rat stomach and duodenum. The resulting digesta are characterised in terms of cell (wall) integrity as well as intracellular starch and protein hydrolysis. The cells remained essentially intact in the model with negligible (ca. 2-3%) starch or protein digestion; however when the cells were mechanically broken and digested in the model, the hydrolysis was increased to 45-50% suggesting that intact cellular structures could survive the mixing regimes in the model stomach and duodenum sufficiently to prevent digestive enzyme access. Apart from intact cell walls providing effective barrier properties, they also limit digestibility by restricting starch gelatinisation during cooking, and significant non-specific binding of α-amylase is observed to both intact and broken cell wall components, providing a third mechanism hindering starch hydrolysis. The study suggests that the preservation of intactness of plant cells, such as from legumes, could be a viable approach to achieve the targeted delivery of resistant starch to the colon.

Stabilization of α-amylase by using anionic surfactant during the immobilization process

Science.gov (United States)

El-Batal, A. I.; Atia, K. S.; Eid, M.

2005-10-01

This work describes the entrapment of α-amylase into butylacrylate-acrylic acid copolymer (BuA/AAc) using γ irradiation. The effect of an anionic surfactant (AOT), the reuse efficiency, and kinetic behavior of immobilized α-amylase were studied. Covering of α-amylase with bis-(2-ethylhexyl)sulfosuccinate sodium salt (AOT) made the enzyme more stable than the uncovered form. The hydrolytic activity of the pre-coated immobilized α-amylase was increased below the critical micelle concentration (cmc) (10 mmol/L). The results showed an increase in the relative activity with increase in the degree of hydration. The pre-coated immobilized α-amylase showed a higher k/K and lower activation energy compared to the free and uncoated-immobilized preparation, respectively. The results suggest that the immobilization of α-amylase is a potentially useful approach for commercial starch hydrolysis in two-phase systems.

Effect of reducing dietary forage in lower starch diets on performance, ruminal characteristics, and nutrient digestibility in lactating Holstein cows.

Science.gov (United States)

Farmer, E R; Tucker, H A; Dann, H M; Cotanch, K W; Mooney, C S; Lock, A L; Yagi, K; Grant, R J

2014-09-01

This experiment evaluated the effect of feeding a lower starch diet (21% of dry matter) with different amounts of forage (52, 47, 43, and 39% of dry matter) on lactational performance, chewing activity, ruminal fermentation and turnover, microbial N yield, and total-tract nutrient digestibility. Dietary forage consisted of a mixture of corn and haycrop silages, and as dietary forage content was reduced, chopped wheat straw (0-10% of dry matter) was added in an effort to maintain chewing activity. Dietary concentrate was adjusted (corn meal, nonforage fiber sources, and protein sources) to maintain similar amounts of starch and other carbohydrate and protein fractions among the diets. Sixteen lactating Holstein cows were used in replicated 4×4 Latin squares with 21-d periods. Dry matter intake increased while physically effective neutral detergent fiber (peNDF1.18) intake was reduced as forage content decreased from 52 to 39%. However, reducing dietary forage did not influence milk yield or composition, although we observed changes in dry matter intake. Time spent chewing, eating, and ruminating (expressed as minutes per day or as minutes per kilogram of NDF intake) were not affected by reducing dietary forage. However, addition of chopped wheat straw to the diets resulted in greater time spent chewing and eating per kilogram of peNDF1.18 consumed. Reducing dietary forage from 52 to 39% did not affect ruminal pH, ruminal digesta volume and mass, ruminal pool size of NDF or starch, ruminal digesta mat consistency, or microbial N yield. Ruminal acetate-to-propionate ratio was reduced, ruminal turnover rates of NDF and starch were greater, and total-tract digestibility of fiber diminished as dietary forage content decreased. Reducing the dietary forage content from 52 to 39% of dry matter, while increasing wheat straw inclusion to maintain chewing and rumen function, resulted in similar milk yield and composition although feed intake increased. With the lower starch

Effects of Sorghum [Sorghum bicolor (L. Moench] Crude Extracts on Starch Digestibility, Estimated Glycemic Index (EGI, and Resistant Starch (RS Contents of Porridges

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Dilek Lemlioglu-Austin

2012-09-01

Full Text Available Bran extracts (70% aqueous acetone of specialty sorghum varieties (tannin, black, and black with tannin were used to investigate the effects of sorghum phenolic compounds on starch digestibility, Estimated Glycemic Index (EGI, and Resistant Starch (RS of porridges made with normal corn starch, enzyme resistant high amylose corn starch, and ground whole sorghum flours. Porridges were cooked with bran extracts in a Rapid Visco-analyser (RVA. The cooking trials indicated that bran extracts of phenolic-rich sorghum varieties significantly reduced EGI, and increased RS contents of porridges. Thus, there could be potential health benefits associated with the incorporation of phenolic-rich sorghum bran extracts into foods to slow starch digestion and increase RS content.

Resistant starch and energy balance: impact on weight loss and maintenance.

Science.gov (United States)

Higgins, Janine A

2014-01-01

The obesity epidemic has prompted researchers to find effective weight-loss and maintenance tools. Weight loss and subsequent maintenance are reliant on energy balance--the net difference between energy intake and energy expenditure. Negative energy balance, lower intake than expenditure, results in weight loss whereas positive energy balance, greater intake than expenditure, results in weight gain. Resistant starch has many attributes, which could promote weight loss and/or maintenance including reduced postprandial insulinemia, increased release of gut satiety peptides, increased fat oxidation, lower fat storage in adipocytes, and preservation of lean body mass. Retention of lean body mass during weight loss or maintenance would prevent the decrease in basal metabolic rate and, therefore, the decrease in total energy expenditure, that occurs with weight loss. In addition, the fiber-like properties of resistant starch may increase the thermic effect of food, thereby increasing total energy expenditure. Due to its ability to increase fat oxidation and reduce fat storage in adipocytes, resistant starch has recently been promoted in the popular press as a "weight loss wonder food". This review focuses on data describing the effects of resistant starch on body weight, energy intake, energy expenditure, and body composition to determine if there is sufficient evidence to warrant these claims.

Maltase-glucoamylase modulates gluconeogenesis and sucrase-isomaltase dominates starch digestion glucogenesis

Science.gov (United States)

Six enzyme activities are needed to digest starch to absorbable free glucose; 2 luminal alpha-amylases (AMY) and 4 mucosal maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) subunit activities are involved in the digestion. The AMY activities break down starch to soluble oligomeric dextrins; mu...

Physicochemical studies on starches isolated from plantain cultivars, plantain hybrids and cooking bananas

Energy Technology Data Exchange (ETDEWEB)

Eggleston, G.; Akoni, S. (International Inst. of Tropical Agriculture, Ibadan (Nigeria)); Swennen, R. (Catholic Univ. of Leuven, Heverlee (Belgium). Lab. of Tropical Husbandry)

1992-04-01

Starches from mature, unripe fruit pulp of plantain cultivars (Musa supp., AAB group) representing the wide variability in Africa, tetraploid and diploid plantain hybrids and starchy cooking bananas (Musa spp., ABB group) were isolated and characterised. In general, studies revealed very compact irregularly shaped and sized granules, with low amylose content (9.11-17.16%), highly resistant to bacterial {alpha}-amylase attack; Brabender amylograms showed very restricted swelling type patterns with great stability and negligible retrogradation. Results indicate that differences in physico-chemical properties exist amongst the three Musa fruit group starches. Plantains represent a chemical/molecular homogeneous group, but heterogeneous for granule structure. Ploidy level affected hybrid properties. ABB cooking bananas starches exhibited highly pronounced restricted swelling and high gelatinisation and pasting temperatures, indicating a more ordered, very strongly bonded granule structure; chemical and physical properties varied considerably within the ABB genotype. (orig.).

Alternative method for quantification of alfa-amylase activity.

Science.gov (United States)

Farias, D F; Carvalho, A F U; Oliveira, C C; Sousa, N M; Rocha-Bezerrra, L C B; Ferreira, P M P; Lima, G P G; Hissa, D C

2010-05-01

A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 A degrees C. A linear relationship between the logarithm of enzyme activities and the area of clear zones was obtained. The method was validated by testing alpha-amylase from barley at the concentrations of 2.4; 60; 300 and 1,500 U.mL-1. The proposed method turned out to be simpler, faster, less expensive and able to determine on a macro-scale alpha-amylase over a wide range (2.4 to 7,500 U.mL-1) in scientific investigation as well as in teaching laboratory activities.

Alternative method for quantification of alfa-amylase activity

Directory of Open Access Journals (Sweden)

DF. Farias

Full Text Available A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 °C. A linear relationship between the logarithm of enzyme activities and the area of clear zones was obtained. The method was validated by testing α-amylase from barley at the concentrations of 2.4; 60; 300 and 1,500 U.mL-1. The proposed method turned out to be simpler, faster, less expensive and able to determine on a macro-scale α-amylase over a wide range (2.4 to 7,500 U.mL-1 in scientific investigation as well as in teaching laboratory activities.

The effect of alpha amylase enzyme on quality of sweet sorghum juice for chrystal sugar

Science.gov (United States)

Marwati, T.; Cahyaningrum, N.; Widodo, S.; Astiati, U. T.; Budiyanto, A.; Wahyudiono; Arif, A. B.; Richana, N.

2018-01-01

Sweet sorghum juice (Sorghum bicolor L. Moench) has characteristics similar to sugar cane juice and potentially used for sugar substitutes that can support food security. Nevertheless the sweet sorghum juicecontain starch which impede sorghum sugar crystallization. Therefore, research on the enzymatic process is needed to convert starch into reducing sugar. The experimental design used was the Factorial Randomized Design with the first factor was alpha amylase enzyme concentration (0, 20, 40, 60, 80, 100, 120 μL/100 mL) and second factor was incubation time (0, 30, 60, 90 minute) at temperature 100°C. The experiment was conducted on fresh sweet sorghum. The results showed that the addition of the alpha amylase enzyme increased the content of reducing sugar and decreased levels of starch. Elevating concentration of alpha amylase enzyme will increase the reducing sugar content in sweet sorghum juice. The optimum alpha amylase enzyme concentration to produce the highest total sugar was 80 μL/100 mL of sweet sorghum juice with the optimum incubation time was 90 minutes. The results of this study are expected to create a new sweetener for sugar substitution. From the economic prospective aspect, sorghum is a potential crop and can be relied upon to support the success of the food diversification program which further leads to the world food security

Long-term effect of resistant starch on cancer risk in carriers of hereditary colorectal cancer

DEFF Research Database (Denmark)

Mathers, John C; Movahedi, Mohammad; Macrae, Finlay

2012-01-01

have been done. We assessed the effect of resistant starch on the incidence of colorectal cancer. METHODS: In the CAPP2 study, individuals with Lynch syndrome were randomly assigned in a two-by-two factorial design to receive 600 mg aspirin or aspirin placebo or 30 g resistant starch or starch placebo...

Thermophilic amylase from Thermus sp. isolation and its potential application for bioethanol production

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Amin Fatoni

2012-11-01

Full Text Available Limited reserves of fossil energy stimulate researchers to explore for a new alternative energy, such as bioethanol.A thermophilic amylase producing bacterium was isolated from local hot-springs and its characteristic and potential applicationfor bioethanol production was determined. The obtained amylase was studied to determine its optimum temperature, pH,enzymatic reaction time, and substrate concentration. Tapioca waste was used as the substrate to find the potential of theamylase for degrading starch into glucose, and then the process was continued by fermentation to produce bioethanol. Theamylase producer bacterium was proposed as genus Thermus sp. The crude amylase that was obtained has the optimumtemperature of 60°C and optimum pH of 8.0, optimum substrate concentration at 10% (w/w and optimum enzymatic reactiontime of 45 minutes. These enzymes convert the starches of waste tapioca at optimum conditions, with the result of 2.9%ethanol produced from raw materials.

Effect of ionizing radiation on starch and cellulose

International Nuclear Information System (INIS)

Klenha, J.; Bockova, J.

1973-09-01

The investigation is reported of the effects of ionizing radiation both on macromolecular systems generally and on polysaccharides, starch and cellulose. Attention is focused on changes in the physical and physico-chemical properties of starch and cellulose, such as starch swelling, gelation, viscosity, solubility, reaction with iodine, UV, IR and ESR spectra, chemical changes resulting from radiolysis and from the effect of amylases on irradiated starch, changes in cellulose fibre strength, water absorption, stain affinity, and also the degradation of cellulose by radiation and the effect of cellulases on irradiated cellulose. Practical applications of the findings concerning cellulose degradation are discussed. (author)

Purification and physicochemical properties of α-amylase from irradiated wheat

International Nuclear Information System (INIS)

Machaiah, J.P.; Vakil, U.K.

1981-01-01

α-Amylases from control and gamma-irradiated (at 0.2 and 2.0 kGy dose levels) wheat seedlings were purified to homogeneity and characterized. The molecular weight of the enzyme from a 2 kGy irradiated sample was slightly lower than that of the control; other general and catalytic properties also showed some differences. α-Amylase from the irradiated (2kGy) sample had a narrow range of pH optimum and was inactivated faster at alkaline pH and by heat treatment than the enzyme from unirradiated wheat. A high apparent Michaelis constant (Ksub(m)) and a low maximal velocity (Vsub(max)) for the hydrolysis of soluble starch catalyzed by the enzyme from irradiated (2kGy) wheat, suggested some modifications in the formation of the substrate α-amylase complex. Further, of the total number of amino acid residues lost on irradiation, dicarboxylic amino acids constituted the largest percentage; these structural alterations in the enzyme may be responsible for its partial inactivation. The total sugars liberated upon amylolysis of starch with the 2kGy irradiated enzyme were lower than control, and there was accumulation of higher maltodextrins in the place of maltose. (auth.)

Effects of dietary resistant starch content on metabolic status, milk composition, and microbial profiling in lactating sows and on offspring performance.

Science.gov (United States)

Yan, H; Lu, H; Almeida, V V; Ward, M G; Adeola, O; Nakatsu, C H; Ajuwon, K M

2017-02-01

In the present study, the effects of dietary resistant starch (RS) content on serum metabolite and hormone concentrations, milk composition, and faecal microbial profiling in lactating sows, as well as on offspring performance was investigated. Sixteen sows were randomly allotted at breeding to two treatments containing low- and high-RS contents from normal and high-amylose corn varieties, respectively, and each treatment had eight replicates (sows). Individual piglet body weight (BW) and litter size were recorded at birth and weaning. Milk samples were obtained on day 10 after farrowing for composition analysis. On day 2 before weaning, blood and faecal samples were collected to determine serum metabolite and hormone concentrations and faecal microbial populations, respectively. Litter size at birth and weaning were not influenced (p > 0.05) by the sow dietary treatments. Although feeding the RS-rich diet to sows reduced (p = 0.004) offspring birth BW, there was no difference in piglet BW at weaning (p > 0.05). High-RS diet increased (p content, and tended (p = 0.09) to increase milk fat content in lactating sows. Feeding the RS-rich diet to sows increased (p bacterial population diversity. These results indicate that high-RS diets induce fatty acid mobilization and a greater intestinal bacterial richness in lactating sows, as well as a greater nutrient density in maternal milk, without affecting offspring performance at weaning. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Secretory expression of Rhizopus oryzae α-amylase in ...

African Journals Online (AJOL)

Kluyveromyces lactis is a non-conventional yeast species extensively used in the expression of heterologous genes. In this study, a genetically modified K. lactis with high-level expression of α- amylase from Rhizopus oryzae was obtained, which could successfully hydrolyze and use starch for growth very well. Shake flask ...

Stabilization of {alpha}-amylase by using anionic surfactant during the immobilization process

Energy Technology Data Exchange (ETDEWEB)

El-Batal, A.I. [National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt); Atia, K.S. [Nuclear Research Center, Radioisotopes Applications Division, Abo-Zable, P.O. Box 13759, Cairo (Egypt)]. E-mail: ks_atia@yahoo.com; Eid, M. [National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)

2005-10-01

This work describes the entrapment of {alpha}-amylase into butylacrylate-acrylic acid copolymer (BuA/AAc) using {gamma} irradiation. The effect of an anionic surfactant (AOT), the reuse efficiency, and kinetic behavior of immobilized {alpha}-amylase were studied. Covering of {alpha}-amylase with bis-(2-ethylhexyl)sulfosuccinate sodium salt (AOT) made the enzyme more stable than the uncovered form. The hydrolytic activity of the pre-coated immobilized {alpha}-amylase was increased below the critical micelle concentration (cmc) (10mmol/L). The results showed an increase in the relative activity with increase in the degree of hydration. The pre-coated immobilized {alpha}-amylase showed a higher k{sub cat}/K{sub m} and lower activation energy compared to the free and uncoated-immobilized preparation, respectively. The results suggest that the immobilization of {alpha}-amylase is a potentially useful approach for commercial starch hydrolysis in two-phase systems.

Stabilization of α-amylase by using anionic surfactant during the immobilization process

International Nuclear Information System (INIS)

El-Batal, A.I.; Atia, K.S.; Eid, M.

2005-01-01

This work describes the entrapment of α-amylase into butylacrylate-acrylic acid copolymer (BuA/AAc) using γ irradiation. The effect of an anionic surfactant (AOT), the reuse efficiency, and kinetic behavior of immobilized α-amylase were studied. Covering of α-amylase with bis-(2-ethylhexyl)sulfosuccinate sodium salt (AOT) made the enzyme more stable than the uncovered form. The hydrolytic activity of the pre-coated immobilized α-amylase was increased below the critical micelle concentration (cmc) (10mmol/L). The results showed an increase in the relative activity with increase in the degree of hydration. The pre-coated immobilized α-amylase showed a higher k cat /K m and lower activation energy compared to the free and uncoated-immobilized preparation, respectively. The results suggest that the immobilization of α-amylase is a potentially useful approach for commercial starch hydrolysis in two-phase systems

Optimisation of resistant starch II and III levels in durum wheat pasta to reduce in vitro digestibility while maintaining processing and sensory characteristics.

Science.gov (United States)

Aravind, Nisha; Sissons, Mike; Fellows, Christopher M; Blazek, Jaroslav; Gilbert, Elliot P

2013-01-15

Foods with elevated levels of resistant starch (RS) may have beneficial effects on human health. Pasta was enriched with commercial resistant starches (RSII, Hi Maize™ 1043; RSIII, Novelose 330™) at 10%, 20% and 50% substitution of semolina for RSII and 10% and 20% for RSIII and compared with pasta made from 100% durum wheat semolina to investigate technological, sensory, in vitro starch digestibility and structural properties. The resultant RS content of pasta increased from 1.9% to ∼21% and was not reduced on cooking. Significantly, the results indicate that 10% and 20% RSII and RSIII substitution of semolina had no significant effects on pasta cooking loss, texture and sensory properties, with only a minimal reduction in pasta yellowness. Both RS types lowered the extent of in vitro starch hydrolysis compared to that of control pasta. X-ray diffraction and small-angle scattering verified the incorporation of RS and, compared to the control sample, identified enhanced crystallinity and a changed molecular arrangement following digestion. These results can be contrasted with the negative impact on pasta resulting from substitution with equivalent amounts of more traditional dietary fibre such as bran. The study suggests that these RS-containing formulations may be ideal sources for the preparation of pasta with reduced starch digestibility. Copyright © 2012 Elsevier Ltd. All rights reserved.

Impact of ancient cereals, pseudocereals and legumes on starch hydrolysis and antiradical activity of technologically viable blended breads.

Science.gov (United States)

Collar, Concha; Jiménez, Teresa; Conte, Paola; Fadda, Costantino

2014-11-26

Wheat flour replacement from 22.5% up to 45% by incorporation of ternary blends of teff (T), green pea (GP) and buckwheat (BW) flours provided technologically viable and acceptable sensory rated multigrain breads with superior nutritional value compared to the 100% wheat flour (WT) counterparts. Blended breads exhibited superior nutritional composition, larger amounts of bioaccessible polyphenols, higher anti-radical activity, and lower and slower starch digestibility. Simultaneous lower rapidly digestible starch (57.1%) and higher slowly digestible starch (12.9%) and resistant starch (2.8%) contents (g per 100g fresh bread), considered suitable nutritional trends for dietary starch fractions, were met by the blend formulated 7.5% T, 15% GP, 15% BK. The associated mixture that replaced 37.5% WT, showed a rather lower extent and slower rate of starch hydrolysis with medium-low values for C∞, and H90, and lowest k, and intermediate expected Glycaemic Index (86). All multigrain breads can be labelled as source of dietary fibre (≥ 3 g dietary fibre/100g bread). Copyright © 2014 Elsevier Ltd. All rights reserved.

Nanosilver: A Catalyst in Enzymatic Hydrolysis of Starch

Directory of Open Access Journals (Sweden)

Falkowska Marta

2014-09-01

Full Text Available Silver nanoparticles are widely used, because of their antimicrobial properties. In this paper, the rate of starch digestion in the presence of nanocatalyst was compared with the rate of reaction without nanosilver. The rate of enzymatic degradation of starch was found to be increased in the presence of silver nanoparticles. It is considered that α-amylase was immobilized onto the surface of nanoparticles.

Expression and comparative characterization of complete and C-terminally truncated forms of saccharifying α-amylase from Lactobacillus plantarum S21.

Science.gov (United States)

Kanpiengjai, Apinun; Nguyen, Thu-Ha; Haltrich, Dietmar; Khanongnuch, Chartchai

2017-10-01

Lactobacillus plantarum S21 α-amylase possesses 475 amino acids at the C-terminal region identified as the starch-binding domain (SBD) and has been previously reported to play a role in raw starch degradation. To understand the specific roles of this SBD, cloning and expression of the complete (AmyL9) and C-terminally truncated (AmyL9Δ SBD ) forms of α-amylase were conducted for enzyme purification and comparative characterization. AmyL9 and AmyL9Δ SBD were overproduced in Escherichia coli at approximately 10- and 20-times increased values of volumetric productivity when compared to α-amylase produced by the wild type, respectively. AmyL9Δ SBD was unable to hydrolyze raw starch and exhibited substrate specificity in a similar manner to that of AmyL9, but it was weakly active toward amylopectin and glycogen. The hydrolysis products obtained from the amylaceous substrates of both enzymes were the same. In addition, AmyL9Δ SBD showed comparatively higher K m values than AmyL9 when it reacted with starch and amylopectin, and lower values for other kinetic constants namely v max , k cat , and k cat /K m . The results indicated that the C-terminal SBDs of L. plantarum S21 α-amylase contribute to not only substrate preference but also substrate affinity and the catalytic efficiency of the α-amylase without any changes in the degradation mechanisms of the enzyme. Copyright © 2017 Elsevier B.V. All rights reserved.

Metabolism of early-lactation dairy cows as affected by dietary starch and monensin supplementation.

Science.gov (United States)

McCarthy, M M; Yasui, T; Ryan, C M; Pelton, S H; Mechor, G D; Overton, T R

2015-05-01

The objective of this study was to evaluate the effect of dietary starch content and monensin (MON) on metabolism of dairy cows during early lactation. Before parturition, primiparous (n=21) and multiparous (n=49) Holstein cows were fed a common controlled-energy close-up diet with a daily topdress of either 0 or 400mg/d monensin. From d 1 to 21 postpartum, cows were fed a high-starch (HS; 26.2% starch, 34.3% neutral detergent fiber, 22.7% acid detergent fiber, 15.5% crude protein) or low-starch (LS; 21.5% starch, 36.9% neutral detergent fiber, 25.2% acid detergent fiber, 15.4% crude protein) total mixed ration with a daily topdress of either 0mg/d monensin (CON) or 450mg/d monensin (MON), continuing with prepartum topdress assignment. From d 22 through 63 postpartum, all cows were fed HS and continued with the assigned topdress treatment until d 63. Cows fed HS had higher plasma glucose and insulin and lower nonesterified fatty acids (NEFA) than cows fed LS during d 1 to 21 postpartum. Cows fed LS had elevated early-lactation β-hydroxybutyrate (BHBA) compared with cows fed HS. Cows fed HS had greater insulin resistance and increased plasma haptoglobin in the early lactation period. There was no effect of MON on postpartum plasma NEFA. Cows fed MON had higher plasma glucose compared with CON cows, which was driven by a MON × parity interaction in which primiparous cows fed MON had greater plasma glucose concentrations than cows fed CON. Cows fed MON had lower plasma BHBA compared with CON, which was contributed to by a MON × parity interaction in which primiparous cows fed MON had lower BHBA concentrations than CON. Starch treatment had no effect on overall liver triglyceride content. Primiparous cows fed MON had increased liver triglyceride content compared with CON primiparous cows, and multiparous cows fed MON had decreased liver triglyceride content compared with CON cows. Multiparous cows fed LS with MON had higher liver glycogen content than multiparous

Inhibition of starch absorption by dietary fibre. A comparative study of wheat bran, sugar-beet fibre, and pea fibre

DEFF Research Database (Denmark)

Hamberg, O; Rumessen, J J; Gudmand-Høyer, E

1989-01-01

The effect of dietary fibre on starch absorption was investigated in 8 healthy subjects. Amounts of starch escaping small-bowel absorption was assessed by comparison of breath H2 excretion after test meals and after lactulose (10g). After ingestion of bread made from 100g of wheat flour increases...

Correlation of pasting behaviors with total phenolic compounds and starch digestibility of indigenous pigmented rice grown in upper Northern Thailand

Directory of Open Access Journals (Sweden)

Jirapa Ponjanta

2016-03-01

Full Text Available Background: Thailand has one of the most important rice genetic resources with white, light brown, brown, red, and purple rice bran colors. The latter believed to have potential for health benefits due to their phenolic content. Recently researchers have indicated that starch digestive enzymes, including salivary and pancreatic α-amylases and α-glucosidases, can be inhibited by phenolic compounds. Although pasting properties of rice flour are key determinants of quality significantly impacting the final product texture, there is no in-depth study on their correlation with phenolic compound and starch digestibility. Methods: Rice flour from twelve varieties, three from each of five bran colors (white, brown, red, and purple, were evaluated for pasting properties (RVA-3D, total phenolic compounds, amylose content, resistant starch and estimated glycemic index. Simple correlation coefficients were calculated for the relationships between pasting properties (final viscosity, breakdown, setback and pasting temperature and total phenolic compounds, resistant starch and estimated glycemic index. Results: Within each rice variety, red and purple pigmented flours had higher total phenolic compounds (TPC and more resistant starch than that of white flours. The TPC and resistant starch content of the flours ranged between 7.83- 47.3 mg/L and 2.44–10.50% respectively, and producing 60-80 of estimated glycemic index. Viscosity behavior showed that pigmented with low amylose rice had lower viscosity temperature than that of pigmented with high amylose rice flour, but higher in peak viscosity. Correlation coefficients of pasting temperature, final viscosity, break down and setback with TCP was observed to be inversely related to glycemic index. However, it was positively correlated to the resistant starch and amylose content. Conclusions: Pigmented rice flour is a better source of TPC and resistant starch which in turn provides low glycemic index. This

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

OpenAIRE

Jnnifer A. Sánchez; Margarita M. Correa; Ángel E. Aceves Dies; Laura M. Castañeda Sandoval

2014-01-01

Bacillus cereus is a food contaminant and a known human pathogen that can cause emetic and diarrheal syndromes. In this study we evaluated the presence of toxigenic B. cereus by multiplex PCR directly in dietary complement for children and cassava starch samples collected on Medellin, Colombia. Of 75 dietary complement for children samples evaluated, 70.7% were contaminated with toxigenic B. cereus and four different toxigenic consortia were detected: I: nheA, hblC, cytK (9.8%), II: nheA, hbl...

Engineering of factors determining alpha-amylase and cyclodextrin glycosyltransferase specificity in the cyclodextrin glycosyltransferase from Thermoanaerobacterium thermosulfurigenes EM1

NARCIS (Netherlands)

Wind, RD; Buitelaar, RM; Dijkhuizen, L

1998-01-01

The starch-degrading enzymes alpha-amylase and cyclodextrin glycosyltransferase (CGTase) are functionally and structurally closely related, with CGTases containing two additional domains (called D and E) compared to the three domains of alpha-amylases (A, B and C). Amino acid residue 196

Rice starch granule amylolysis--differentiating effects of particle size, morphology, thermal properties and crystalline polymorph.

Science.gov (United States)

Dhital, Sushil; Butardo, Vito M; Jobling, Stephen A; Gidley, Michael J

2015-01-22

The underlying mechanism of amylolysis of rice starch granules was investigated using isolated starch granules from wild-type, as well as SBEIIb mutant and down-regulated lines. Fused granule agglomerates isolated from mutant and transgenic lines were hydrolysed at similar rates by amylases, and had similar crystalline patterns and thermal properties as individual granules. Surface pores, a feature previously only reported for A-polymorphic starch granules, were also observed in B- and C-polymorphic rice starch granules. Although the microscopic patterns of hydrolysis among granules with different crystalline polymorphs were qualitatively similar, the extent and the rate of amylolysis were different, suggesting that B-type crystalline polymorphs are intrinsically more resistant to enzymatic hydrolysis than A-type in rice starch granules. It is proposed that the slightly longer branch lengths of amylopectin which leads to the formation of more stable B-type double helical structures compared to their A-type counterparts is the major parameter, with other factors such as granule size, surface pores and interior channels having secondary roles, in determining the rate of enzymatic hydrolysis of rice starch granules. Copyright © 2014 Elsevier Ltd. All rights reserved.

POTENTIAL USE OF AN EXTRACELLULAR ENZYME OF a-AMYLASE FROM INDIGENOUS INDONESIAN MESOPHILIC BACTERIA

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Puji Lestari

2013-04-01

Full Text Available Amylase enzyme has a great significance for industrial usages in  Indonesia. However, this enzyme is still imported. The use of bacteria in biotechnological process of industrial products such as enzyme production has stimulated the exploration of extracellular amylase producing  bacteria. This study aimed to identify and analyze the potential use of amylolytic bacterial enzymes for hydrolyzing cassava starch. Two bacterial isolates, i.e. MII-10 and DKW-8 originated from Indonesia soil were identified based on their morphological, physiological and biochemical properties according to the standard protocol. The isolates were then  cultivated on fermentation medium and their growth pattern and  enzymatic assays were observed. The acetone-precipitated crude enzyme harvested based on predetermined cultivation time was used for  enzymatic hydrolysis product characterization on cassava starch using thin layer chromatography (TLC. The results showed that the mesophilicbacteria isolates (MII-10 and DKW-8 were belonged to Bacillus licheniformis. The maximum bacterial cell growth and enzyme activity were reached at 48 hours after incubation. The MII-10 isolate was found more stable than DKW-8 in producing amylase enzyme. Amylase produced by the MII-10 and DKW- 8 isolates was identified to be an endo-a-amylase as confirmed by oligosaccharides and dextrin of the random hydrolysisproducts. Relatively high dextrose equivalence (DE value of a-amylase of MII-10 (DE of 9.96 suggests that the enzyme is prospective for  saccharification of starchy material in glucose syrup industry.

Development of modified starch technology (maltodextrin) from commercial tapioca on semi production scale using oil heater dextrinator

Science.gov (United States)

Triyono, Agus; Cecep Erwan Andriansyah, Raden; Luthfiyanti, Rohmah; Rahman, Taufik

2017-12-01

One way to improve functional starch is by modification of starch into dextrin or maltodextrin. Maltodextrin is used in the food industry as a food substitution. Development of enzymatically modified starch technology has been performed with the use of α-amylase at optimum pH of 5.5, temperature 75-85 °C, with enzyme activity of 135 KNU/g. The maltodextrin produced from commercial tapioca has the quality requirements for food according to SNI 1992. The yield of maltodextrin obtained is about 80%. The use of the optimum amount of the α-amylase enzyme is 0.07 % v/w and the substrate amount of tapioca starch is 35%. Analysis of the feasibility of modified starch with the assumption of production scale of 300 kg per day, the economic value of 10 years business, the price of starch is IDR 8,350/kg, from tapioca starch (tapioca) IDR 4,000 - IDR 4,500/kg.

A hyper-thermostable α-amylase from Pyrococcus furiosus accumulates in Nicotiana tabacum as functional aggregates.

Science.gov (United States)

Zhu, Hong; Reynolds, L Bruce; Menassa, Rima

2017-06-19

Alpha amylase hydrolyzes α-bonds of polysaccharides such as starch and produces malto-oligosaccharides. Its starch saccharification applications make it an essential enzyme in the textile, food and brewing industries. Commercially available α-amylase is mostly produced from Bacillus or Aspergillus. A hyper-thermostable and Ca 2++ independent α-amylase from Pyrococcus furiosus (PFA) expressed in E.coli forms insoluble inclusion bodies and thus is not feasible for industrial applications. We expressed PFA in Nicotiana tabacum and found that plant-produced PFA forms functional aggregates with an accumulation level up to 3.4 g/kg FW (fresh weight) in field conditions. The aggregates are functional without requiring refolding and therefore have potential to be applied as homogenized plant tissue without extraction or purification. PFA can also be extracted from plant tissue upon dissolution in a mild reducing buffer containing SDS. Like the enzyme produced in P. furiosus and in E. coli, plant produced PFA preserves hyper-thermophilicity and hyper-thermostability and has a long shelf life when stored in lyophilized leaf tissue. With tobacco's large biomass and high yield, hyper-thermostable α-amylase was produced at a scale of 42 kg per hectare. Tobacco may be a suitable bioreactor for industrial production of active hyperthermostable alpha amylase.

Enamel and dentine demineralization by a combination of starch and sucrose in a biofilm – caries model

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Juliana Nunes BOTELHO

2016-01-01

Full Text Available Abstract Sucrose is the most cariogenic dietary carbohydrate and starch is considered non-cariogenic for enamel and moderately cariogenic for dentine. However, the cariogenicity of the combination of starch and sucrose remains unclear. The aim of this study was to evaluate the effect of this combination on Streptococcus mutans biofilm composition and enamel and dentine demineralization. Biofilms of S. mutans UA159 were grown on saliva-coated enamel and dentine slabs in culture medium containing 10% saliva. They were exposed (8 times/day to one of the following treatments: 0.9% NaCl (negative control, 1% starch, 10% sucrose, or 1% starch and 10% sucrose (starch + sucrose. To simulate the effect of human salivary amylase on the starch metabolization, the biofilms were pretreated with saliva before each treatment and saliva was also added to the culture medium. Acidogenicity of the biofilm was estimated by evaluating (2 times/day the culture medium pH. After 4 (dentine or 5 (enamel days of growth, biofilms (n = 9 were individually collected, and the biomass, viable microorganism count, and polysaccharide content were quantified. Dentine and enamel demineralization was assessed by determining the percentage of surface hardness loss. Biofilms exposed to starch + sucrose were more acidogenic and caused higher demineralization (p < 0.0001 on either enamel or dentine than those exposed to each carbohydrate alone. The findings suggest that starch increases the cariogenic potential of sucrose.

Effects of exogenous gamma-aminobutyric acid on α-amylase activity in the aleurone of barley seeds.

Science.gov (United States)

Sheng, Yidi; Xiao, Huiyuan; Guo, Chunli; Wu, Hong; Wang, Xiaojing

2018-03-03

Gamma-aminobutyric acid (GABA), a nonprotein amino acid, often accumulates in plants exposed to certain environmental stimuli. Previous studies indicated that a closed relationship existed between endogenous GABA and seed germination. However, there are few studies on the effect of exogenous GABA on seed germination. The objective of this study was to explore whether exogenous GABA affected α-amylase activity which the activation is an important stage in seed germination. The level of endogenous GABA in barley seeds rose gradually during germination, suggesting that endogenous GABA was involved in germination. We measured starch degradation under application of various concentration GABA and found that GABA promoted seed starch degradation with a dose-responsive effect. The relationship between GABA and α-amylase activity was investigated by treating barley aleurone with exogenous GABA. The result showed that α-amylase activity began to rise after about 24 h and reached a peak at 48 h. Molecular evidence suggested that GABA increased α-amylase gene expression. We explore the possible roles played by GABA in signal transduction. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Physical and biological treatments of polyethylene-rice starch plastic films

Energy Technology Data Exchange (ETDEWEB)

El-Naggar, Manal M.A., E-mail: mmelnaggar@yahoo.com [Microbiology Lab., National Institute of Oceanography and Fisheries, Alexandria (Egypt); Farag, Magdy Gh. [Development Plastic Center, Victoria, Alexandria (Egypt)

2010-04-15

This study aimed to produce an industrial applicable thermo-stable {alpha}-amylase from marine Bacillus amyloliquefaciens which isolated and selected according to its significant enzyme production. The effect of different pH values and temperatures on the bacterial growth and the enzyme production was estimated using an experimental statistical design; maximum amylase production and bacterial growth was obtained at pH 7.0 and 50 deg. C. Some biodegradable polyethylene rice starch plastic films (PERS-P) were manufactured using 0, 2.5, 5, 7.5 and 10% starch concentrations. The biodegradability (reduction in the plastic elongation%) was tested using the exposure to UV radiation at {lambda}{sub 300-400nm} (intensity of about 1000 W/m{sup 2}) and the produced B. amyloliquefaciens thermo-stable {alpha}-amylase. A significant reduction in the elongation% of these biodegradable plastics was observed in both cases especially on testing the 10% PERS-P; they showed a reduction of 26% and 20%, respectively, compared to the untreated plastic films (180 {+-} 5).

Physical and biological treatments of polyethylene-rice starch plastic films

International Nuclear Information System (INIS)

El-Naggar, Manal M.A.; Farag, Magdy Gh.

2010-01-01

This study aimed to produce an industrial applicable thermo-stable α-amylase from marine Bacillus amyloliquefaciens which isolated and selected according to its significant enzyme production. The effect of different pH values and temperatures on the bacterial growth and the enzyme production was estimated using an experimental statistical design; maximum amylase production and bacterial growth was obtained at pH 7.0 and 50 deg. C. Some biodegradable polyethylene rice starch plastic films (PERS-P) were manufactured using 0, 2.5, 5, 7.5 and 10% starch concentrations. The biodegradability (reduction in the plastic elongation%) was tested using the exposure to UV radiation at λ 300-400nm (intensity of about 1000 W/m 2 ) and the produced B. amyloliquefaciens thermo-stable α-amylase. A significant reduction in the elongation% of these biodegradable plastics was observed in both cases especially on testing the 10% PERS-P; they showed a reduction of 26% and 20%, respectively, compared to the untreated plastic films (180 ± 5).

Purification and physicochemical properties of. cap alpha. -amylase from irradiated wheat

Energy Technology Data Exchange (ETDEWEB)

Machaiah, J P; Vakil, U K [Bhabha Atomic Research Centre, Bombay (India). Biochemistry and Food Technology Div.

1981-06-01

..cap alpha..-Amylases from control and gamma-irradiated (at 0.2 and 2.0 kGy dose levels) wheat seedlings were purified to homogeneity and characterized. The molecular weight of the enzyme from a 2 kGy irradiated sample was slightly lower than that of the control; other general and catalytic properties also showed some differences. ..cap alpha..-Amylase from the irradiated (2kGy) sample had a narrow range of pH optimum and was inactivated faster at alkaline pH and by heat treatment than the enzyme from unirradiated wheat. A high apparent Michaelis constant (Ksub(m)) and a low maximal velocity (Vsub(max)) for the hydrolysis of soluble starch catalyzed by the enzyme from irradiated (2kGy) wheat, suggested some modifications in the formation of the substrate ..cap alpha..-amylase complex. Further, of the total number of amino acid residues lost on irradiation, dicarboxylic amino acids constituted the largest percentage; these structural alterations in the enzyme may be responsible for its partial inactivation. The total sugars liberated upon amylolysis of starch with the 2kGy irradiated enzyme were lower than control, and there was accumulation of higher maltodextrins in the place of maltose.

Production of a Thermostable Α-Amylase and its Assay using ...

African Journals Online (AJOL)

Screening for amylolytic properties from obtained isolates was carried out on starch agar plates while production and characterization of α-amylase was carried out using submerged fermentation. The isolated organism was identified as Bacillus licheniformis. Physiological studies on the isolate showed that temperature of ...

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

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Demiate Ivo Mottin

2001-01-01

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

Production of α-amylase from Streptomyces sp. SLBA-08 strain using agro-industrial by-products

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Édilla Ribeiro dos Santos

2012-10-01

Full Text Available Approximately 1.5 trillion tons are the estimated yearly biomass production, making it an essentially unlimited source of raw material for environmentally friendly and biocompatible products transformed by microorganism, specially fungi and actinomycetes. Several lignocellulosic residues, such as sisal waste and sugarcane bagasse contain starch in their structures which could become important sources for the production of amylases. This study evaluated the production of amylolytic enzymes using Streptomyces sp. SLBA-08 strain, isolated from a semi-arid soil, according to their ability to grow on soluble starch as the sole carbon source. The effect of the carbon source (sisal waste and sugarcane bagasse on α-amylase production was studied using submerged cultivations at 30 ºC. The highest level of α-amylase activity corresponded to 10.1 U. mL-1 and was obtained using sisal waste (2.7% and urea (0.8% in submerged fermentation after 3 days of cultivation. The partial characterization showed the best α-amylase activity at 50ºC and pH 7.0. These results are of great importance for the use of sisal waste as a substrate for biotechnological proposes.

Physical structure and absorption properties of tailor-made porous starch granules produced by selected amylolytic enzymes.

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Yi-Seul Jung

Full Text Available Porous starch granules (PSGs with various pores and cavity sizes were prepared by amylolysis enzymes. The greatest hydrolysis rate on corn starch granule was observed with α-amylase, followed by gluco- and β-amylases. Temperature increase enhanced glucoamylase reaction rate more drastically than other enzyme treatments. Final hydrolysis level with glucoamylase reached to 66.9%, close to 67.5% of α-amylolysis. The α-amylase-treated PSGs displayed the greatest pore size and ratio of cavity-to-granule diameters. Gelatinization onset temperatures of PSGs increased to 72.1 (α-, 68.7 (β-, and 68.1°C (gluco-amylolysis after 8 h; enthalpy changes of β- and gluco-amylase-treated PSGs increased to 13.4, and 13.1 J/g but α-amylase-treated one showed slightly reduced value of 8.5 J/g. Water holding capacities of PSGs were 209.7 (α-, 94.6 (β-, and 133.8% (gluco-amylolysis, and the untreated control had 89.1%; oil holding capacities of them showed 304.5, 182.7, and 211.5%, respectively, while the untreated control had 161.8%. Thus, enzyme types and their reaction conditions can be applied to generate desirable cavity and pore sizes in starch granules. This biocatalytic approach could contribute to develop tailor-made PSGs with distinct internal structure for specific uses in wide range of food, pharmaceutical and other industrial applications.

Physical structure and absorption properties of tailor-made porous starch granules produced by selected amylolytic enzymes

Science.gov (United States)

Jung, Yi-seul; Lee, Byung-Hoo

2017-01-01

Porous starch granules (PSGs) with various pores and cavity sizes were prepared by amylolysis enzymes. The greatest hydrolysis rate on corn starch granule was observed with α-amylase, followed by gluco- and β-amylases. Temperature increase enhanced glucoamylase reaction rate more drastically than other enzyme treatments. Final hydrolysis level with glucoamylase reached to 66.9%, close to 67.5% of α-amylolysis. The α-amylase-treated PSGs displayed the greatest pore size and ratio of cavity-to-granule diameters. Gelatinization onset temperatures of PSGs increased to 72.1 (α-), 68.7 (β-), and 68.1°C (gluco-amylolysis) after 8 h; enthalpy changes of β- and gluco-amylase-treated PSGs increased to 13.4, and 13.1 J/g but α-amylase-treated one showed slightly reduced value of 8.5 J/g. Water holding capacities of PSGs were 209.7 (α-), 94.6 (β-), and 133.8% (gluco-amylolysis), and the untreated control had 89.1%; oil holding capacities of them showed 304.5, 182.7, and 211.5%, respectively, while the untreated control had 161.8%. Thus, enzyme types and their reaction conditions can be applied to generate desirable cavity and pore sizes in starch granules. This biocatalytic approach could contribute to develop tailor-made PSGs with distinct internal structure for specific uses in wide range of food, pharmaceutical and other industrial applications. PMID:28727742

Co-conjugation vis-à-vis individual conjugation of α-amylase and glucoamylase for hydrolysis of starch.

Science.gov (United States)

Jadhav, Swati B; Singhal, Rekha S

2013-10-15

Two enzymes, α-amylase and glucoamylase have been individually and co-conjugated to pectin by covalent binding. Both the enzyme systems showed better thermal and pH stability over the free enzyme system with the complete retention of original activities. Mixture of individually conjugated enzymes showed lower inactivation rate constant with longer half life than the co-conjugated enzyme system. Individually conjugated enzymes showed an increase of 56.48 kJ/mole and 38.22 kJ/mole in activation energy for denaturation than the free enzymes and co-conjugated enzymes, respectively. Km as well as Vmax of individually and co-conjugated enzymes was found to be higher than the free enzymes. SDS-polyacrylamide gel electrophoresis confirmed the formation of conjugate and co-conjugate as evident by increased molecular weight. Both the enzyme systems were used for starch hydrolysis where individually conjugated enzymes showed highest release of glucose at 60 °C and pH 5.0 as compared to free and co-conjugated enzyme. Copyright © 2013 Elsevier Ltd. All rights reserved.

Assessment of the influence of amylose-LPC complexation on the extent of wheat starch digestibility by size-exclusion chromatography.

Science.gov (United States)

Ahmadi-Abhari, S; Woortman, A J J; Hamer, R J; Loos, K

2013-12-15

Amylose forms inclusion complexes with lysophosphatidylcholine (LPC), that decrease the susceptibility of amylose to amylase degradation. This study on the influence of complexation on starch susceptibility to amylase explains the nature of this protective effect. Wheat starch suspensions (9% w/w) containing 0.5-5% LPC were subjected to hydrolysis by porcine pancreatic α-amylase at 37 °C for several digestion times. The digesta were analysed by size-exclusion chromatography (SEC). The molar mass distribution was closely dependent on the digestion time and amount of LPC. This study precisely demonstrates the alteration of the digestion profile of starch on a molecular level, influenced by amylose-LPC complexation; however the effect depends on the digestion time. During 15 and 30 min digestion, inclusion complexes not only protect amylopectin in the initial hydrolysis stage, but also demonstrate lower susceptibility of the molecular amylose complexes to amylase hydrolysis. Digestion for 240 min resulted in a lower oligosaccharide peak concentration, in the presence of a high LPC concentration, which is related to less degradation of complexed amylose fraction. Copyright © 2013 Elsevier Ltd. All rights reserved.

Milk production and composition responds to dietary neutral detergent fiber and starch ratio in dairy cows.

Science.gov (United States)

Zhao, Meng; Bu, Dengpan; Wang, Jiaqi; Zhou, Xiaoqiao; Zhu, Dan; Zhang, Ting; Niu, Junli; Ma, Lu

2016-06-01

This study was designed to investigate whether dietary neutral detergent fiber (NDF) : starch ratio could be considered as a nutritional indicator to evaluate carbohydrate composition and manipulate milk production and composition synthesis. Eight primiparous dairy cows were assigned to four total mixed rations with NDF : starch ratios of 0.86, 1.18, 1.63 and 2.34 from T1 to T4 in a replicated 4 × 4 Latin square design. Dry matter intake and milk production were decreased from T1 to T4. Digestibility of dry matter, organic matter, NDF and crude protein were linearly decreased from T1 to T4. As NDF : starch ratio increased, milk protein content and production, and milk lactose content and production were linearly reduced. However, milk fat content was linearly increased from T1 to T4. Quadratic effect was observed on milk fat production with the highest level in T3. Averaged rumen pH was linearly increased from T1 to T4, and subacute rumen acidosis occurred in T1. Ruminal propionate and butyrate concentration were linearly decreased, and microbial crude protein and metabolizable protein decreased from T1 to T4. It is concluded that NDF : starch ratio can be considered as a potential indicator to evaluate dietary carbohydrate composition and manipulate milk production and composition synthesis. © 2015 Japanese Society of Animal Science.

Screening of traditional antidiabetic medicinal plants of Mauritius for possible alpha-amylase inhibitory effects in vitro.

Science.gov (United States)

Kotowaroo, M I; Mahomoodally, M F; Gurib-Fakim, A; Subratty, A H

2006-03-01

In this study, seven exotic/indigenous medicinal plants of Mauritius, namely Coix lacryma-jobi (Poaceae), Aegle marmelos (Rutaceae), Artocarpus heterophyllus (Moraceae), Vangueria madagascariensis (Rubiaceae), Azadirachta indica (Meliaceae), Eriobotrya japonica (Rosaceae) and Syzigium cumini (Myrtaceae) were studied for possible effects on starch breakdown by alpha-amylase in vitro. The results showed that only Artocarpus heterophyllus significantly (p Artocarpus heterophyllus on alpha-amylase activity using rat plasma in vitro. It was found that the aqueous leaf extract significantly (p Artocarpus heterophyllus behaved as a competitive inhibitor. Results from the present study tend to indicate that Artocarpus heterophyllus could act as a 'starch blocker' thereby reducing post-prandial glucose peaks. Copyright 2006 John Wiley & Sons, Ltd.

Digestibility of gluten proteins is reduced by baking and enhanced by starch digestion.

Science.gov (United States)

Smith, Frances; Pan, Xiaoyan; Bellido, Vincent; Toole, Geraldine A; Gates, Fred K; Wickham, Martin S J; Shewry, Peter R; Bakalis, Serafim; Padfield, Philip; Mills, E N Clare

2015-10-01

Resistance of proteins to gastrointestinal digestion may play a role in determining immune-mediated adverse reactions to foods. However, digestion studies have largely been restricted to purified proteins and the impact of food processing and food matrices on protein digestibility is poorly understood. Digestibility of a total gliadin fraction (TGF), flour (cv Hereward), and bread was assessed using in vitro batch digestion with simulated oral, gastric, and duodenal phases. Protein digestion was monitored by SDS-PAGE and immunoblotting using monoclonal antibodies specific for celiac-toxic sequences (QQSF, QPFP) and starch digestion by measuring undigested starch. Whereas the TGF was rapidly digested during the gastric phase the gluten proteins in bread were virtually undigested and digested rapidly during the duodenal phase only if amylase was included. Duodenal starch digestion was also slower in the absence of duodenal proteases. The baking process reduces the digestibility of wheat gluten proteins, including those containing sequences active in celiac disease. Starch digestion affects the extent of protein digestion, probably because of gluten-starch complex formation during baking. Digestion studies using purified protein fractions alone are therefore not predictive of digestion in complex food matrices. © 2015 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous delivery of antibiotics neomycin and ampicillin in drinking water inhibits fermentation of resistant starch in rats.

Science.gov (United States)

Carvajal-Aldaz, Diana G; Guice, Justin L; Page, Ryan C; Raggio, Anne M; Martin, Roy J; Husseneder, Claudia; Durham, Holiday A; Geaghan, James; Janes, Marlene; Gauthier, Ted; Coulon, Diana; Keenan, Michael J

2017-03-01

Antibiotics ampicillin 1 g/L and neomycin 0.5 g/L were added to drinking water before or during feeding of resistant starch (RS) to rats to inhibit fermentation. In a preliminary study, antibiotics and no RS were given prior to rats receiving a transplant of cecal contents via gavage from donor rats fed RS (without antibiotics) or a water gavage before feeding resistant starch to both groups. Antibiotics given prior to feeding RS did not prevent later fermentation of RS regardless of either type of gavage. In the second study, antibiotics were given simultaneously with feeding of RS. This resulted in inhibition of fermentation of RS with cecal contents pH >8 and low amounts of acetate and butyrate. Rats treated with antibiotics had reduced Bifidobacteria spp., but similar Bacteroides spp. to control groups to reduce acetate and butyrate and preserve the production of propionate. Despite reduced fermentation, rats given antibiotics had increased glucagon-like peptide 1 (GLP-1) and cecum size, measures that are usually associated with fermentation. A simultaneous delivery of antibiotics inhibited fermentation of RS. However, increased GLP-1 and cecum size would be confounding effects in assessing the mechanism for beneficial effects of dietary RS by knocking out fermentation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

THE IMPORTANCE OF DIETARY CARBOHYDRATE IN HUMAN EVOLUTION.

Science.gov (United States)

Hardy, Karen; Brand-Miller, Jennie; Brown, Katherine D; Thomas, Mark G; Copeland, Les

2015-09-01

ABSTRACT We propose that plant foods containing high quantities of starch were essential for the evolution of the human phenotype during the Pleistocene. Although previous studies have highlighted a stone tool-mediated shift from primarily plant-based to primarily meat-based diets as critical in the development of the brain and other human traits, we argue that digestible carbohydrates were also necessary to accommodate the increased metabolic demands of a growing brain. Furthermore, we acknowledge the adaptive role cooking played in improving the digestibility and palatability of key carbohydrates. We provide evidence that cooked starch, a source of preformed glucose, greatly increased energy availability to human tissues with high glucose demands, such as the brain, red blood cells, and the developing fetus. We also highlight the auxiliary role copy number variation in the salivary amylase genes may have played in increasing the importance of starch in human evolution following the origins of cooking. Salivary amylases are largely ineffective on raw crystalline starch, but cooking substantially increases both their energy-yielding potential and glycemia. Although uncertainties remain regarding the antiquity of cooking and the origins of salivary amylase gene copy number variation, the hypothesis we present makes a testable prediction that these events are correlated.

Leucine Affects α-Amylase Synthesis through PI3K/Akt-mTOR Signaling Pathways in Pancreatic Acinar Cells of Dairy Calves.

Science.gov (United States)

Guo, Long; Liang, Ziqi; Zheng, Chen; Liu, Baolong; Yin, Qingyan; Cao, Yangchun; Yao, Junhu

2018-05-23

Dietary nutrient utilization, particularly starch, is potentially limited by digestion in dairy cow small intestine because of shortage of α-amylase. Leucine acts as an effective signal molecular in the mTOR signaling pathway, which regulates a series of biological processes, especially protein synthesis. It has been reported that leucine could affect α-amylase synthesis and secretion in ruminant pancreas, but mechanisms have not been elaborated. In this study, pancreatic acinar (PA) cells were used as a model to determine the cellular signal of leucine influence on α-amylase synthesis. PA cells were isolated from newborn Holstein dairy bull calves and cultured in Dulbecco's modifed Eagle's medium/nutrient mixture F12 liquid media containing four leucine treatments (0, 0.23, 0.45, and 0.90 mM, respectively), following α-amylase activity, zymogen granule, and signal pathway factor expression detection. Rapamycin, a specific inhibitor of mTOR, was also applied to PA cells. Results showed that leucine increased ( p synthesis of α-amylase as well as phosphorylation of PI3K, Akt, mTOR, and S6K1 while reduced ( p synthesis. In addition, the extracellular leucine dosage significantly influenced intracellular metabolism of isoleucine ( p synthesis through promoting the PI3K/Akt-mTOR pathway and reducing the GCN2 pathway in PA cells of dairy calves. These pathways form the signaling network that controls the protein synthesis and metabolism. It would be of great interest in future studies to explore the function of leucine in ruminant nutrition.

Diets high in resistent starch and arabinoxylan modulate digestion processes and SCFA pool size in the large intestine and faecal microbial composition in pigs

DEFF Research Database (Denmark)

Nielsen, Tina Skau; Lærke, Helle Nygaard; Theil, Peter Kappel

2014-01-01

The effects of a high level of dietary fibre (DF) either as arabinoxylan (AX) or resistant starch (RS) on digestion processes, SCFA concentration and pool size in various intestinal segments and on the microbial composition in the faeces were studied in a model experiment with pigs. A total...... resulted in a 3- to 5-fold higher pool size of butyrate compared with WSD feeding, with the RSD being intermediate (P microbial composition towards butyrogenic...

Role of resistant starch on diabetes risk factors in people with prediabetes: Design, conduct, and baseline results of the STARCH trial.

Science.gov (United States)

Marlatt, Kara L; White, Ursula A; Beyl, Robbie A; Peterson, Courtney M; Martin, Corby K; Marco, Maria L; Keenan, Michael J; Martin, Roy J; Aryana, Kayanush J; Ravussin, Eric

2018-02-01

Dietary resistant starch (RS) might alter gastrointestinal tract function in a manner that improves human health, particularly among adults at risk for diabetes. Here, we report the design and baseline results (with emphasis on race differences) from the STARCH trial, the first comprehensive metabolic phenotyping of people with prediabetes enrolled in a randomized clinical trial testing the effect of RS on risk factors for diabetes. Overweight/obese participants (BMI≥27kg/m 2 and weight≤143kg), age 35-75y, with confirmed prediabetes were eligible. Participants were randomized to consume 45g/day of RS (RS=amylose) or amylopectin (Control) for 12weeks. The study was designed to evaluate the effect of RS on insulin sensitivity and secretion, ectopic fat, and inflammatory markers. Secondary outcomes included energy expenditure, substrate oxidation, appetite, food intake, colonic microbial composition, fecal and plasma levels of short-chain fatty acids, fecal RS excretion, and gut permeability. Out of 280 individuals screened, 68 were randomized, 65 started the intervention, and 63 were analyzed at baseline (mean age 55y, BMI 35.6kg/m 2 ); 2 were excluded from baseline analyses due to abnormal insulin and diabetes. Sex and race comparisons at baseline were reported. African-Americans had higher baseline acute insulin response to glucose (AIRg measured by frequently sampled intravenous glucose tolerance test) compared to Caucasians, despite having less visceral adipose tissue mass and intrahepatic lipid; all other glycemic variables were similar between races. Sleep energy expenditure was ~90-100kcal/day lower in African-Americans after adjusting for insulin sensitivity and secretion. This manuscript provides an overview of the strategy used to enroll people with prediabetes into the STARCH trial and describes methodologies used in the assessment of risk factors for diabetes. Clinicaltrials.gov identifier: STARCH (NCT01708694). The present study reference can be

Prebiotic properties of potato starch dextrins

Directory of Open Access Journals (Sweden)

Renata Barczyńska

2015-09-01

Full Text Available The objective of the present study was to compare the prebiotic properties of starch dextrins, that is, resistant dextrins obtained from potato starch in the process of simultaneous thermolysis and chemical modification, which were selected based on previous research. Both prepared dextrins met the definition criterion of dietary fiber and also the basic prebiotic criterion – they were not degraded by the digestive enzymes of the initial sections of the gastrointestinal tract. The growth of probiotic lactobacilli and bifidobacteria, as well as Escherichia coli, Enterococcus, Bacteroides, and Clostridium strains isolated from feces of healthy people, showed that both studied dextrins were utilized as a source of assimilable carbon and energy by the strains. Furthermore, better growth (higher numbers of cells counts of probiotic bacteria than those of fecal isolates indicated that the studied resistant dextrins showed a selective effect. Both dextrins might be considered as substances with prebiotic properties due to their chemical and physical properties and selectivity towards the studied probiotic bacterial strains.

UTILIZATION OF CORN STARCH AS SUBSTRATE FOR Я

African Journals Online (AJOL)

IITA

substrate, 10.1 X102 CFU/ml soluble starch and nutrient broth medium ... enzymatic activity with corresponding maltose yield of 46.4mg/ml and 68.0mg/ml .... stand for 15min at room temperature, the ... order to inactivated the beta amylase.

Preparation of resistant sweet potato starch by steam explosion ...

African Journals Online (AJOL)

resistant sweet potato starch was identified by Fourier transform infrared ... can potentially be used in food or medicine for diabetic patients. ... were suspended in water (1:3.5, w/v), and ..... No conflict of interest associated with this work.

Evaluation of grain nutritional quality and resistant starch content

African Journals Online (AJOL)

USER

contained considerable levels zinc, iron, resistant starch and low levels of the undesirable phytic acid. Key Words: Iron, phytic ... processes, which in turn influence nutrient uptake ..... in diets and level of processing, daily intake can be as high ...

Monte Carlo simulation of the alpha-amylolysis of amylopectin potato starch. 2. alpha-amylolysis of amylopectin

NARCIS (Netherlands)

Marchal, L.M.; Ulijn, R.V.; Gooijer, de C.D.; Franke, G.T.; Tramper, J.

2003-01-01

A model is presented that describes all the saccharides that are produced during the hydrolysis of starch by an alpha-amylase. Potato amylopectin, the substrate of the hydrolysis reaction, was modeled in a computer matrix. The four different subsite maps presented in literature for alpha-amylase

Pancreatic α-Amylase Controls Glucose Assimilation by Duodenal Retrieval through N-Glycan-specific Binding, Endocytosis, and Degradation*

Science.gov (United States)

Date, Kimie; Satoh, Ayano; Iida, Kaoruko; Ogawa, Haruko

2015-01-01

α-Amylase, a major pancreatic protein and starch hydrolase, is essential for energy acquisition. Mammalian pancreatic α-amylase binds specifically to glycoprotein N-glycans in the brush-border membrane to activate starch digestion, whereas it significantly inhibits glucose uptake by Na+/glucose cotransporter 1 (SGLT1) at high concentrations (Asanuma-Date, K., Hirano, Y., Le, N., Sano, K., Kawasaki, N., Hashii, N., Hiruta, Y., Nakayama, K., Umemura, M., Ishikawa, K., Sakagami, H., and Ogawa, H. (2012) Functional regulation of sugar assimilation by N-glycan-specific interaction of pancreatic α-amylase with glycoproteins of duodenal brush border membrane. J. Biol. Chem. 287, 23104–23118). However, how the inhibition is stopped was unknown. Here, we show a new mechanism for the regulation of intestinal glucose absorption. Immunohistochemistry revealed that α-amylase in the duodena of non-fasted, but not fasted, pigs was internalized from the pancreatic fluid and immunostained. We demonstrated that after N-glycan binding, pancreatic α-amylase underwent internalization into lysosomes in a process that was inhibited by α-mannoside. The internalized α-amylase was degraded, showing low enzymatic activity and molecular weight at the basolateral membrane. In a human intestinal Caco-2 cell line, Alexa Fluor 488-labeled pancreatic α-amylase bound to the cytomembrane was transported to lysosomes through the endocytic pathway and then disappeared, suggesting degradation. Our findings indicate that N-glycan recognition by α-amylase protects enterocytes against a sudden increase in glucose concentration and restores glucose uptake by gradual internalization, which homeostatically controls the postprandial blood glucose level. The internalization of α-amylase may also enhance the supply of amino acids required for the high turnover of small intestine epithelial cells. This study provides novel and significant insights into the control of blood sugar during the absorption

Characterization of salivary alpha-amylase binding to Streptococcus sanguis

International Nuclear Information System (INIS)

Scannapieco, F.A.; Bergey, E.J.; Reddy, M.S.; Levine, M.J.

1989-01-01

The purpose of this study was to identify the major salivary components which interact with oral bacteria and to determine the mechanism(s) responsible for their binding to the bacterial surface. Strains of Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans, and Actinomyces viscosus were incubated for 2 h in freshly collected human submandibular-sublingual saliva (HSMSL) or parotid saliva (HPS), and bound salivary components were eluted with 2% sodium dodecyl sulfate. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western transfer, alpha-amylase was the prominent salivary component eluted from S. sanguis. Studies with 125 I-labeled HSMSL or 125 I-labeled HPS also demonstrated a component with an electrophoretic mobility identical to that of alpha-amylase which bound to S. sanguis. Purified alpha-amylase from human parotid saliva was radiolabeled and found to bind to strains of S. sanguis genotypes 1 and 3 and S. mitis genotype 2, but not to strains of other species of oral bacteria. Binding of [ 125 I]alpha-amylase to streptococci was saturable, calcium independent, and inhibitable by excess unlabeled alpha-amylases from a variety of sources, but not by secretory immunoglobulin A and the proline-rich glycoprotein from HPS. Reduced and alkylated alpha-amylase lost enzymatic and bacterial binding activities. Binding was inhibited by incubation with maltotriose, maltooligosaccharides, limit dextrins, and starch

Isolation and partial characterization of starch from banana cultivars grown in Colombia.

Science.gov (United States)

Chávez-Salazar, A; Bello-Pérez, L A; Agama-Acevedo, E; Castellanos-Galeano, F J; Álvarez-Barreto, C I; Pacheco-Vargas, G

2017-05-01

Banana starch is resistant to hydrolysis by digestive enzymes due to its structure and dietary fibre content. Starch was isolated from the following three cultivars of Colombian Musaceae: Gros Michel (dessert), Dominico Harton and FHIA 20 (cooking); also, the amylose and amylopectin contents, morphology of the granules, thermal properties, pasting, molecular characteristics and digestibility were determined. The total starch content, amylose content and digestibility (gelatinized starch) were higher in cooking varieties; the purity and gelatinization temperature were similar for the three varieties, but the enthalpy was higher in the dessert variety. The three varieties showed higher viscosities in the pasting profile compared to commercial maize starch in both acid and neutral conditions. Starch granules presented with heterogeneous sizes and shapes (elongated and ovals) that had birefringence. The Dominico Hartón variety showed the lowest rapidly digestible starch (RDS) value in the gelatinized sample that is in agreement with the greater proportion of long chains. Copyright © 2017 Elsevier B.V. All rights reserved.

Properties and applications of starch-converting enzymes of the α-amylase family

NARCIS (Netherlands)

Maarel, Marc J.E.C. van der; Veen, Bart van der; Uitdehaag, Joost C.M.; Leemhuis, Hans; Dijkhuizen, L.

2002-01-01

Starch is a major storage product of many economically important crops such as wheat, rice, maize, tapioca, and potato. A large-scale starch processing industry has emerged in the last century. In the past decades, we have seen a shift from the acid hydrolysis of starch to the use of

Properties and applications of starch-converting enzymes of the alpha-amylase family

NARCIS (Netherlands)

van der Maarel, MJEC; van der Veen, B; Uitdehaag, JCM; Leemhuis, H; Dijkhuizen, L

2002-01-01

Starch is a major storage product of many economically important crops such as wheat, rice, maize, tapioca, and potato. A large-scale starch processing industry has emerged in the last century. In the past decades, we have seen a shift from the acid hydrolysis of starch to the use of

Genetic Engineering of Cereal Grains with Starch Consisting of More Than 99% Amylase

DEFF Research Database (Denmark)

Hebelstrup, Kim; Carciofi, Massimiliano; Blennow, Andreas

2013-01-01

Numerous textbooks tell us that plant starches are a mix of two starch types: amylopectin and amylose. We recently succeeded in engineering a cereal crop – a barley line – producing grain starch consisting of more than 99% amylose1. This amylose-only starch contains a high residual fraction...

The Effects of Treatments on Batu Banana Flour and Percentage of Wheat Substitution on The Resistant Starch, In Vitro Starch Digestibility Content and Palatability of Cookies Made with Banana (Musa balbisiana Colla) Flour

Science.gov (United States)

Ratnasari, D.; Rustanti, N.; Arifan, F.; Afifah, DN

2018-02-01

Diabetes mellitus (DM) is the most common endocrine disease worldwide. Resistant starch is polysaccharide that is recommended for DM patient diets. One of the staple crops containing resistant starch is banana. It is the fourth most important staple crop in the world and critical for food security, best suited plant in warm, frost-free, and coastal climates area. Among banana varieties, Batu bananas (Musa balbisiana Colla) had the highest content of resistant starch (~39%), but its use as a food ingredient is limited. Inclusion of Batu banana flour into cookies manufacturing would both increase the economic value of Batu bananas and provide alternative snacks for DM patients. Here we sought to examine whether cookies made with modified Batu banana flour would be a suitable snack for DM patients. This study used a completely randomized design with two factors: substitution of Batu banana flour (25%, 50%,75%) for wheat-based flour and Batu banana flour treatment methods (no treatment, autoclaving-cooling, autoclaving-cooling-spontaneous fermentation). The resistant starch and in vitro starch digestibility levels were analyzed using two-way ANOVA and Tukey test, whereas the acceptance level was analyzed by Friedman and Wilcoxon tests. The content of resistant starch and in vitro starch digestibility of the different treatments ranged from 3.10 to 15.79% and 16.03 to 52.59%, respectively. Both factors differed significantly (p0.05). Meanwhile, palatability in terms of color, aroma, texture, and flavor differed significantly among the different treatments and starch contents (ppatients. Keywords: Batu banana, cookies, resistant starch, in vitro starch digestibility

Purification of (potato)-starch manufacture waste water utilizing the residual pulp

Energy Technology Data Exchange (ETDEWEB)

Malcher, J

1956-01-01

Diagrams and procedures are given for fermentation of potato-starch-factory wastes and production of ethanol, butanol, acetone, and amylase. The combined process gives 95% recovery of the total solids of potatoes.

Production, Purification, and Characterization of Thermostable α-Amylase Produced by Bacillus licheniformis Isolate AI20

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Yasser R. Abdel-Fattah

2013-01-01

Full Text Available An optimization strategy, based on statistical experimental design, is employed to enhance the production of thermostable α-amylase by a thermotolerant B. licheniformis AI20 isolate. Using one variant at time (OVAT method, starch, yeast extract, and CaCl2 were observed to influence the enzyme production significantly. Thereafter, the response surface methodology (RSM was adopted to acquire the best process conditions among the selected variables, where a three-level Box-Behnken design was employed to create a polynomial quadratic model correlating the relationship between the three variables and α-amylase activity. The optimal combination of the major constituents of media for α-amylase production was 1.0% starch, 0.75% yeast extract, and 0.02% CaCl2. The predicted optimum α-amylase activity was 384 U/mL/min, which is two folds more than the basal medium conditions. The produced α-amylase was purified through various chromatographic techniques. The estimated enzyme molecular mass was 55 kDa and the α-amylase had an optimal temperature and pH of 60–80°C and 6–7.5, respectively. Values of Vmax and Km for the purified enzyme were 454 mU/mg and 0.709 mg/mL. The α-amylase enzyme showed great stability against different solvents. Additionally, the enzyme activity was slightly inhibited by detergents, sodium dodecyl sulphate (SDS, or chelating agents such as EDTA and EGTA. On the other hand, great enzyme stability against different divalent metal ions was observed at 0.1 mM concentration, but 10 mM of Cu2+ or Zn2+ reduced the enzyme activity by 25 and 55%, respectively.

Partial characterization of chayotextle starch-based films added with ascorbic acid encapsulated in resistant starch.

Science.gov (United States)

Martínez-Ortiz, Miguel A; Vargas-Torres, Apolonio; Román-Gutiérrez, Alma D; Chavarría-Hernández, Norberto; Zamudio-Flores, Paul B; Meza-Nieto, Martín; Palma-Rodríguez, Heidi M

2017-05-01

Chayotextle starch was modified by subjecting it to a dual treatment with acid and heating-cooling cycles. This caused a decrease in the content of amylose, which showed values of 30.22%, 4.80%, 3.27% and 3.57% for native chayotextle starch (NCS), starch modified by acid hydrolysis (CMS), and CMS with one (CMS1AC) and three autoclave cycles (CMS3AC), respectively. The percentage of crystallinity showed an increase of 36.9%-62% for NCS and CMS3AC. The highest content of resistant starch (RS) was observed in CMS3AC (37.05%). The microcapsules were made with CMS3AC due to its higher RS content; the total content of ascorbic acid of the microcapsules was 82.3%. The addition of different concentrations of CMS3AC microcapsules (0%, 2.5%, 6.255% and 12.5%) to chayotextle starch-based films (CSF) increased their tensile strength and elastic modulus. The content of ascorbic acid and RS in CSF was ranged from 0% to 59.4% and from 4.84% to 37.05% in the control film and in the film mixed with CMS3AC microcapsules, respectively. Water vapor permeability (WVP) values decreased with increasing concentrations of microcapsules in the films. Microscopy observations showed that higher concentrations of microcapsules caused agglomerations due their poor distribution in the matrix of the films. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of replacing dietary starch with neutral detergent-soluble fibre on ruminal fermentation, microbial synthesis and populations of ruminal cellulolytic bacteria using the rumen simulation technique (RUSITEC).

Science.gov (United States)

Zhao, X H; Liu, C J; Liu, Y; Li, C Y; Yao, J H

2013-12-01

A rumen simulation technique (RUSITEC) apparatus with eight 800 ml fermenters was used to investigate the effects of replacing dietary starch with neutral detergent-soluble fibre (NDSF) by inclusion of sugar beet pulp in diets on ruminal fermentation, microbial synthesis and populations of ruminal cellulolytic bacteria. Experimental diets contained 12.7, 16.4, 20.1 or 23.8% NDSF substituted for starch on a dry matter basis. The experiment was conducted over two independent 15-day incubation periods with the last 8 days used for data collection. There was a tendency that 16.4% NDSF in the diet increased the apparent disappearance of organic matter (OM) and neutral detergent fibre (NDF). Increasing dietary NDSF level increased carboxymethylcellulase and xylanase activity in the solid fraction and apparent disappearance of acid detergent fibre (ADF) but reduced the 16S rDNA copy numbers of Ruminococcus albus in both liquid and solid fractions and R. flavefaciens in the solid fraction. The apparent disappearance of dietary nitrogen (N) was reduced by 29.6% with increased dietary NDSF. Substituting NDSF for starch appeared to increase the ratios of acetate/propionate and methane/volatile fatty acids (VFA) (mol/mol). Replacing dietary starch with NDSF reduced the daily production of ammonia-N and increased the growth of the solid-associated microbial pellets (SAM). Total microbial N flow and efficiency of microbial synthesis (EMS), expressed as g microbial N/kg OM fermented, tended to increase with increased dietary NDSF, but the numerical increase did not continue as dietary NDSF exceeded 20.1% of diet DM. Results suggested that substituting NDSF for starch up to 16.4% of diet DM increased digestion of nutrients (except for N) and microbial synthesis, and further increases (from 16.4% to 23.8%) in dietary NDSF did not repress microbial synthesis but did significantly reduce digestion of dietary N. © 2012 Blackwell Verlag GmbH.

In vitro Starch Hydrolysis Rate, Physico-chemical Properties and Sensory Evaluation of Butter Cake Prepared Using Resistant Starch Type III Substituted for Wheat Flour.

Science.gov (United States)

Pongjanta, J; Utaipattanaceep, A; Naivikul, O; Piyachomkwan, K

2008-09-01

Resistant starch type III (RS III) derived from enzymatically debranched high amylose rice starch was prepared and used to make butter cake at different levels (0, 5, 10, 15 and 20%) in place of wheat flour. Physico-chemical properties, sensory evaluation, and in vitro starch hydrolysis rate of the developed butter cake were investigated. This study showed that the content of resistant starch in butter cake increased significantly (Pcake with RS III replacement had a significantly lower in vitro starch hydrolysis rate compared to the control cake (0% RS III). The rates of starch hydrolysis from 0 to 180 min digestion time for 0, 5, 10 15, and 20% RS III in place of wheat flour in butter cakes were 3.70 to 67.65%, 2.97 to 64.86%, 2.86 to 59.99%, 2.79 to 55.96 and 2.78 to 53.04% respectively. The physico-chemical properties of 5 to 10% RS III substituted with wheat flour in the butter cake were not significantly different from the control cake and were moderately accepted by panellists in the sensory evaluation test.

Brewing Science in the Chemistry Laboratory: A "Mashing" Investigation of Starch and Carbohydrates

Science.gov (United States)

Pelter, Michael W.; McQuade, Jennifer

2005-01-01

The experiments that mimic the actual brewing process to explain the science to the nonscience majors is performed using malted barley as the source for both the starch and the amylase enzyme. The experiment introduces the concept of monitoring the progress of chemical reaction and was able to show the chemical breakdown of the starch to simple…

Functional Characterization of Bean Zaragoza Starch (Phaseolus Lunatus L. and Quantification of the Resistant Starch

Directory of Open Access Journals (Sweden)

Piedad M. Montero-Castillo

2013-06-01

Full Text Available Legumes are a potential source of starch, representing between 30 and 50% of its dry weight, this is an essential energy source for humans. Currently its use is widespread in the food industry as an additive or raw material in food compounds, due to its nutritional, functional properties as a thickening agent and stabilizer of suspensions and dispersions. We evaluated several functional properties of starch variety zaragoza red bean, was obtained initial gelatinization temperature and final (71°C (81°C respectively, the solubility was 8.3% at 90°C, swelling power was 6.6% at 80°C, and water retention capacity was 4.4% at 80°C. The apparent viscosity was evaluated between 20 and 75 °C giving as results viscosities between 1.096 and 0.98 Cp respectively. The results showed that the tested temperatures significantly affect the solubility, swelling power, water holding capacity and viscosity of the starch. The amylose and amylopectin content was 21.1% and 78.19%. Finally, was obtained 9,24% resistant starch and compared with other conventional non starchy sources in order to acquire new knowledge about this material native to the Colombian Caribbean coast.

Two secondary carbohydrate binding sites on the surface of barley alpha-amylase 1 have distinct functions and display synergy in hydrolysis of starch granules.

Science.gov (United States)

Nielsen, Morten M; Bozonnet, Sophie; Seo, Eun-Seong; Mótyán, János A; Andersen, Joakim M; Dilokpimol, Adiphol; Abou Hachem, Maher; Gyémánt, Gyöngyi; Naested, Henrik; Kandra, Lili; Sigurskjold, Bent W; Svensson, Birte

2009-08-18

Some polysaccharide processing enzymes possess secondary carbohydrate binding sites situated on the surface far from the active site. In barley alpha-amylase 1 (AMY1), two such sites, SBS1 and SBS2, are found on the catalytic (beta/alpha)(8)-barrel and the noncatalytic C-terminal domain, respectively. Site-directed mutagenesis of Trp(278) and Trp(279), stacking onto adjacent ligand glucosyl residues at SBS1, and of Tyr(380) and His(395), making numerous ligand contacts at SBS2, suggested that SBS1 and SBS2 act synergistically in degradation of starch granules. While SBS1 makes the major contribution to binding and hydrolysis of starch granules, SBS2 exhibits a higher affinity for the starch mimic beta-cyclodextrin. Compared to that of wild-type AMY1, the K(d) of starch granule binding by the SBS1 W278A, W279A, and W278A/W279A mutants thus increased 15-35 times; furthermore, the k(cat)/K(m) of W278A/W279A was 2%, whereas both affinity and activity for Y380A at SBS2 were 10% of the wild-type values. Dual site double and triple SBS1/SBS2 substitutions eliminated binding to starch granules, and the k(cat)/K(m) of W278A/W279A/Y380A AMY1 was only 0.4% of the wild-type value. Surface plasmon resonance analysis of mutants showed that beta-cyclodextrin binds to SBS2 and SBS1 with K(d,1) and K(d,2) values of 0.07 and 1.40 mM, respectively. A model that accounts for the observed synergy in starch hydrolysis, where SBS1 and SBS2 bind ordered and free alpha-glucan chains, respectively, thus targeting the enzyme to single alpha-glucan chains accessible for hydrolysis, is proposed. SBS1 and SBS2 also influence the kinetics of hydrolysis for amylose and maltooligosaccharides, the degree of multiple attack on amylose, and subsite binding energies.

Mutational analysis of target enzyme recognition of the beta-trefoil fold barley alpha-amylase/subtilisin inhibitor

DEFF Research Database (Denmark)

Bønsager, Birgit Christine; Nielsen, Per K.; Abou Hachem, Maher

2005-01-01

The barley alpha-amylase/subtilisin inhibitor ( BASI) inhibits alpha-amylase 2 (AMY2) with subnanomolar affinity. The contribution of selected side chains of BASI to this high affinity is discerned in this study, and binding to other targets is investigated. Seven BASI residues along the AMY2-BASI...... interface and four residues in the putative protease-binding loop on the opposite side of the inhibitor were mutated. A total of 15 variants were compared with the wild type by monitoring the alpha-amylase and protease inhibitory activities using Blue Starch and azoalbumin, respectively, and the kinetics...

Immobilization of Trichoderma harzianum α-amylase on PPyAgNp/Fe3O4-nanocomposite: chemical and physical properties.

Science.gov (United States)

Mohamed, Saleh A; Al-Harbi, Majed H; Almulaiky, Yaaser Q; Ibrahim, Ibrahim H; Salah, Hala A; El-Badry, Mohamed O; Abdel-Aty, Azza M; Fahmy, Afaf S; El-Shishtawy, Reda M

2018-03-26

In this study, a new support has been developed by immobilization of α-amylase onto modified magnetic Fe 3 O 4 -nanoparticles. The characterization of soluble and immobilized α-amylases with regards to kinetic parameters, pH, thermal stability and reusability was studied. The effect of polypyrrole/silver nanocomposite (PPyAgNp) percentage on weight of Fe 3 O 4 and pH on the immobilization of α-amylase was studied. The highest immobilization efficiency (75%) was detected at 10% PPyAgNp/Fe 3 O 4 -nanocomposite and pH 7.0. Immobilization of α-amylase on PPyAgNp/Fe 3 O 4 -nanocomposite was characterized by FT-IR spectroscopy and scanning electron microscopy. The reusability of the immobilized enzyme activity was 80% of its initial activity after 10 reuses. The immobilized enzyme was more stable towards pH, temperature and metal ions compared with soluble enzyme. The kinetic study appeared higher affinity of immobilized enzyme (K m 2.5 mg starch) compared with soluble enzyme (K m 3.5 mg starch). In conclusion, the immobilization of α-amylase on PPyAgNp/Fe 3 O 4 -nanocomposite could successfully be used in industrial and medical applications.

Kinetics of α-amylase and α-glucosidase inhibitory potential of Zea mays Linnaeus (Poaceae), Stigma maydis aqueous extract: An in vitro assessment.

Science.gov (United States)

Sabiu, S; O'Neill, F H; Ashafa, A O T

2016-05-13

Corn silk (Zea mays L., Stigma maydis) is an important herb used traditionally in many parts of the world to treat array of diseases including diabetes mellitus. Inhibitors of α-amylase and α-glucosidase offer an effective strategy to modulate levels of post prandial hyperglycaemia via control of starch metabolism. This study evaluated α-amylase and α-glucosidase inhibitory potentials of corn silk aqueous extract. Active principles and antioxidant attributes of the extract were also analysed. The α-amylase inhibitory potential of the extract was investigated by reacting its different concentrations with α-amylase and starch solution, while α-glucosidase inhibition was determined by pre-incubating α-glucosidase with different concentrations of the extract followed by addition of p-nitrophenylglucopyranoside. The mode(s) of inhibition of the enzymes were determined using Lineweaver-Burke plot. In vitro analysis of the extract showed that it exhibited potent and moderate inhibitory potential against α-amylase and α-glucosidase, respectively. The inhibition was concentration-dependent with respective half-maximal inhibitory concentration (IC50) values of 5.89 and 0.93mg/mL. Phytochemical analyses revealed the presence of alkaloids, flavonoids, phenols, saponins, tannins and phytosterols as probable inhibitory constituents. Furthermore, the extract remarkably scavenges reactive oxygen species like DPPH and nitric oxide radicals, elicited good reducing power and a significant metal chelating attributes. Overall, the non-competitive and uncompetitive mechanism of action of corn silk extract is due to its inhibitory effects on α-amylase and α-glucosidase, respectively. Consequently, this will reduce the rate of starch hydrolysis, enhance palliated glucose levels, and thus, lending credence to hypoglycaemic candidature of corn silk. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Cloning and Characterization of an Alpha-amylase Gene from the Hyperthermophilic Archaeon Thermococcus Thioreducens

Science.gov (United States)

Bernhardsdotter, Eva C. M. J.; Pusey, Marc L.; Ng, Joseph D.; Garriott, Owen K.

2004-01-01

The gene encoding an extracellular a-amylase, TTA, from the hyperthermophilic archaeon Thermococcus thioreducens was cloned and expressed in Escherichia coli. Primary structural analysis revealed high similarity with other a-amylases from the Thermococcus and Pyrococcus genera, as well as the four highly conserved regions typical for a-amylases. The 1374 bp gene encodes a protein of 457 amino acids, of which 435 constitute the mature protein preceded by a 22 amino acid signal peptide. The molecular weight of the purified recombinant enzyme was estimated to be 43 kDa by denaturing gel electrophoresis. Maximal enzymatic activity of recombinant TTA was observed at 90 C and pH 5.5 in the absence of exogenous Ca(2+), and the enzyme was considerably stable even after incubation at 90 C for 2 hours. The thermostability at 90 and 102 C was enhanced in the presence of 5 mM Ca(2+). The extraordinarily high specific activity (about 7.4 x 10(exp 3) U/mg protein at 90 C, pH 5.5 with soluble starch as substrate) together with its low pH optimum makes this enzyme an interesting candidate for starch processing applications.

Comprehensive enzymatic analysis of the amylolytic system in the digestive fluid of the sea hare, Aplysia kurodai: Unique properties of two α-amylases and two α-glucosidases

Directory of Open Access Journals (Sweden)

Akihiko Tsuji

2014-01-01

Full Text Available Sea lettuce (Ulva pertusa is a nuisance species of green algae that is found all over the world. East-Asian species of the marine gastropod, the sea hare Aplysia kurodai, shows a clear feeding preference for sea lettuce. Compared with cellulose, sea lettuce contains a higher amount of starch as a storage polysaccharide. However, the entire amylolytic system in the digestive fluid of A. kurodai has not been studied in detail. We purified α-amylases and α-glucosidases from the digestive fluid of A. kurodai and investigated the synergistic action of these enzymes on sea lettuce. A. kurodai contain two α-amylases (59 and 80 kDa and two α-glucosidases (74 and 86 kDa. The 59-kDa α-amylase, but not the 80-kDa α-amylase, was markedly activated by Ca2+ or Cl−. Both α-amylases degraded starch and maltoheptaose, producing maltotriose, maltose, and glucose. Glucose production from starch was higher with 80-kDa α-amylase than with 59-kDa α-amylase. Kinetic analysis indicated that 74-kDa α-glucosidase prefers short α-1,4-linked oligosaccharide, whereas 86-kDa α-glucosidase prefers large α-1,6 and α-1,4-linked polysaccharides such as glycogen. When sea lettuce was used as a substrate, a 2-fold greater amount of glucose was released by treatment with 59-kDa α-amylase and 74-kDa α-glucosidase than by treatment with 45-kDa cellulase and 210-kDa β-glucosidase of A. kurodai. Unlike mammals, sea hares efficiently digest sea lettuce to glucose by a combination of two α-amylases and two α-glucosidases in the digestive fluids without membrane-bound maltase–glucoamylase and sucrase–isomaltase complexes.

Chemical modification with phthalic anhydride and chitosan: Viable options for the stabilization of raw starch digesting amylase from Aspergillus carbonarius.

Science.gov (United States)

Nwagu, Tochukwu Nwamaka; Okolo, Bartholomew; Aoyagi, Hideki; Yoshida, Shigeki

2017-06-01

The raw starch digesting type of amylase (RSDA) presents greater opportunities for process efficiency at cheaper cost and shorter time compared to regular amylases. Chemical modification is a simple and rapid method toward their stabilization for a wider application. RSDA from Aspergillus carbonarius was modified with either phthalic anhydride (PA) or chitosan. Activity retention was 87.3% for PA-modified and 80.9% for chitosan-modified RSDA. Optimum pH shifted from 5 to 7 after PA-modification. Optimum temperature changed from 30°C (native) to 30-40°C and 60°C for PA-modified and chitosan-modified, respectively. Activation energy (kJmol -1 ) for hydrolysis was 13.5, 12.7, and 10.2 while the activation energy for thermal denaturation was 32.8, 80.3, 81.9 for free, PA-modified and chitosan-modified, respectively. The specificity constants (V max /K m ) were 73.2 for PA-modified, 63.1 for chitosan-modified and 77.1 for native RSDA. The half-life (h) of the RSDA at 80°C was increased from 6.1 to 25.7 for the PA-modified and 138.6 for the chitosan derivative. Modification also led to increase in D value, activation enthalpy and Gibbs free energy of enzyme deactivation. Fluorescence spectra showed that center of spectral mass decreased for the PA-modified RSDA but increased for chitosan modified RSDA. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Dietary Fiber and Its Components on Metabolic Health

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Mark D. Haub

2010-12-01

Full Text Available Dietary fiber and whole grains contain a unique blend of bioactive components including resistant starches, vitamins, minerals, phytochemicals and antioxidants. As a result, research regarding their potential health benefits has received considerable attention in the last several decades. Epidemiological and clinical studies demonstrate that intake of dietary fiber and whole grain is inversely related to obesity, type two diabetes, cancer and cardiovascular disease (CVD. Defining dietary fiber is a divergent process and is dependent on both nutrition and analytical concepts. The most common and accepted definition is based on nutritional physiology. Generally speaking, dietary fiber is the edible parts of plants, or similar carbohydrates, that are resistant to digestion and absorption in the small intestine. Dietary fiber can be separated into many different fractions. Recent research has begun to isolate these components and determine if increasing their levels in a diet is beneficial to human health. These fractions include arabinoxylan, inulin, pectin, bran, cellulose, β-glucan and resistant starch. The study of these components may give us a better understanding of how and why dietary fiber may decrease the risk for certain diseases. The mechanisms behind the reported effects of dietary fiber on metabolic health are not well established. It is speculated to be a result of changes in intestinal viscosity, nutrient absorption, rate of passage, production of short chain fatty acids and production of gut hormones. Given the inconsistencies reported between studies this review will examine the most up to date data concerning dietary fiber and its effects on metabolic health.

α-Amylase inhibitors: a review of raw material and isolated compounds from plant source.

Science.gov (United States)

Sales, Paloma Michelle; Souza, Paula Monteiro; Simeoni, Luiz Alberto; Silveira, Damaris

2012-01-01

Inhibition of α-amylase, enzyme that plays a role in digestion of starch and glycogen, is considered a strategy for the treatment of disorders in carbohydrate uptake, such as diabetes and obesity, as well as, dental caries and periodontal diseases. Plants are an important source of chemical constituents with potential for inhibition of α-amylase and can be used as therapeutic or functional food sources. A review about crude extracts and isolated compounds from plant source that have been tested for α-amylase inhibitory activity has been done. The analysis of the results shows a variety of crude extracts that present α-amylase inhibitory activity and some of them had relevant activity when compared with controls used in the studies. Amongst the phyto-constituents that have been investigated, flavonoids are one of them that demonstrated the highest inhibitory activities with the potential of inhibition related to number of hydroxyl groups in the molecule of the compound. Several phyto-constituents and plant species as α-amylase inhibitors are being reported in this article. Majority of studies have focused on the anti-amylase phenolic compounds.

Amylase production by endophytic fungi Cylindrocephalum sp. isolated from medicinal plant Alpinia calcarata (Haw. Roscoe

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V. H. Sunitha.

2012-09-01

Full Text Available Amylases are among the most important enzymes used in modern biotechnology particularly in the process involving starch hydrolysis. Fungal amylase has large applications in food and pharmaceutical industries. Considering these facts, endophytic fungi isolated from the plant Alpinia calcarata (Haw. Roscoe were screened for amylolytic activity on glucose yeast extract peptone agar (GYP medium. Among thirty isolates of endophytic fungi, isolate number seven identified as Cylindrocephalum sp. (Ac-7 showed highest amylolytic activity and was taken for further study. Influence of various physical and chemical factors such as pH, temperature, carbon and nitrogen sources on amylase production in liquid media were studied. The maximal amylase production was found to be at 30ºC and at pH 7.0 of the growth medium. Among the various carbon and nitrogen sources tested, maltose at 1.5% and Sodium nitrate at 0.3% respectively gave optimum amylase production.

Response surface optimization of low-fat ice cream production by using resistant starch and maltodextrin as a fat replacing agent.

Science.gov (United States)

Azari-Anpar, Mojtaba; Khomeiri, Morteza; Ghafouri-Oskuei, Hamed; Aghajani, Narjes

2017-04-01

In this research, maltodextrin (0, 1 and 2% w/w) and resistant starch (0, 1 and 2% w/w) were used in the formulation of low-fat ice cream (4% fat) and their effects on the physicochemical and sensory properties were investigated. The optimum levels of maltodextrin and resistant starch were determined by response surface methodology. Increment of maltodextrin and resistant starch increased acidity, viscosity, melting rate, time of dripping and overrun but decreased melting rate of ice cream. Results showed that the incorporation of maltodextrin and resistant starch at 0 and 2% w/w respectively, resulted into ice cream with suitable viscosity, melting rate, first dripping time, overrun and acidity.

Inhibition by natural dietary substances of gastrointestinal absorption of starch and sucrose in rats and pigs: 1. Acute studies.

Science.gov (United States)

Preuss, Harry G; Echard, Bobby; Bagchi, Debasis; Stohs, Sidney

2007-08-06

Rapid gastrointestinal absorption of refined carbohydrates (CHO) is linked to perturbed glucose-insulin metabolism that is, in turn, associated with many chronic health disorders. We assessed the ability of various natural substances, commonly referred to as "CHO blockers," to influence starch and sucrose absorption in vivo in ninety-six rats and two pigs. These natural enzyme inhibitors of amylase/sucrase reportedly lessen breakdown of starches and sucrose in the gastrointestinal tract, limiting their absorption. To estimate absorption, groups of nine SD rats were gavaged with water or water plus rice starch and/or sucrose; and circulating glucose was measured at timed intervals thereafter. For each variation in the protocol a total of at least nine different rats were studied with an equal number of internal controls on three different occasions. The pigs rapidly drank CHO and inhibitors in their drinking water. In rats, glucose elevations above baseline over four hours following rice starch challenge as estimated by area-under-curve (AUC) were 40%, 27%, and 85% of their internal control after ingesting bean extract, hibiscus extract, and l-arabinose respectively in addition to the rice starch. The former two were significantly different from control. L-Arabinose virtually eliminated the rising circulating glucose levels after sucrose challenge, whereas hibiscus and bean extracts were associated with lesser decreases than l-arabinose that were still significantly lower than control. The glucose elevations above baseline over four hours in rats receiving sucrose (AUC) were 51%, 43% and 2% of control for bean extract, hibiscus extract, and L-arabinose, respectively. Evidence for dose-response of bean and hibiscus extracts is reported. Giving the natural substances minus CHO challenge caused no significant changes in circulating glucose concentrations, indicating no major effects on overall metabolism. A formula combining these natural products significantly

Heterocyclic Compounds: Effective α-Amylase and α-Glucosidase Inhibitors.

Science.gov (United States)

Saeedi, Mina; Hadjiakhondi, Abbas; Nabavi, Seyed Mohammad; Manayi, Azadeh

2017-01-01

Diabetes Mellitus (DM) is a metabolic disease characterized by high blood sugar levels. Recently, it has emerged as an important and global health problem with long-term complications and high economic burden. α-Amylase (α-Amy) and α-glucosidase (α-Gls) are two enzymes which are involved in the hydrolysis of starch into sugars and disaccharides leading to the increase of blood glucose level. Hence, inhibition of α-amylase and α-glucosidase plays key role in the treatment of type 2 diabetes. Heterocyclic compounds -both synthetic and naturally occurring derivatives- possess efficient biological properties. At this juncture, they have demonstrated potent inhibitory activity against α-Amy and α-Gls and were found to be versatile tools for the development of novel anti-diabetic agents.

Effect of increasing dietary nonfiber carbohydrate with starch, sucrose, or lactose on rumen fermentation and productivity of lactating dairy cows.

Science.gov (United States)

Gao, X; Oba, M

2016-01-01

The objective of this study was to investigate effects of increasing dietary nonfiber carbohydrate (NFC) with starch, sucrose, or lactose on rumen fermentation, volatile fatty acid absorption, and milk production of lactating dairy cows. Twenty-eight multiparous, lactating Holstein cows (141 ± 50 d in milk; 614 ± 53 kg of body weight) including 8 ruminally cannulated cows were used in this study. Cows were assigned to 4 dietary treatments in a 4 × 4 Latin square design with 21-d periods. The treatments were control [27% starch and 4% sugar on a dry matter (DM) basis], a high-NFC diet by increasing dietary starch content (STA; 32% starch and 4% sugar on a DM basis), and 2 more high-NFC diets by increasing dietary sugar content (27% starch and 9% sugar on a DM basis) in which sucrose (SUC) or lactose (LAC) was supplemented. Dry matter intake was greater for cows fed high-NFC diets compared with control diet (27.1 vs. 26.3 kg/d), but rumen pH and milk production did not differ between cows fed control and high-NFC diets. However, cows fed high-disaccharide diets had lower mean rumen pH than those fed STA diet (6.19 vs. 6.32). Although molar proportion of butyrate was greater for high-disaccharide treatments than STA treatment (15.2 vs. 13.7 mol/100 mol), absorption rate of volatile fatty acid in the rumen was not affected by treatment. In addition, cows fed high-disaccharide diets had higher energy-corrected milk yield than cows fed STA diet (39.6 vs. 38.0 kg/d). Dry matter intake did not differ between cows fed 2 high-disaccharide diets. Although cows fed the SUC diet had lower molar proportion of butyrate in the rumen compared with those fed the LAC diet (14.4 vs. 15.9 mol/100 mol), the SUC diet did not decrease rumen pH. In addition, cows fed the SUC diet had lower nutrient digestibility of organic matter than did those fed the LAC diet (59.7 vs. 64.4%), but milk component yields did not differ between the 2 high-disaccharide diet treatments. The results of the

Black leaf streak disease affects starch metabolism in banana fruit.

Science.gov (United States)

Saraiva, Lorenzo de Amorim; Castelan, Florence Polegato; Shitakubo, Renata; Hassimotto, Neuza Mariko Aymoto; Purgatto, Eduardo; Chillet, Marc; Cordenunsi, Beatriz Rosana

2013-06-12

Black leaf streak disease (BLSD), also known as black sigatoka, represents the main foliar disease in Brazilian banana plantations. In addition to photosynthetic leaf area losses and yield losses, this disease causes an alteration in the pre- and postharvest behavior of the fruit. The aim of this work was to investigate the starch metabolism of fruits during fruit ripening from plants infected with BLSD by evaluating carbohydrate content (i.e., starch, soluble sugars, oligosaccharides, amylose), phenolic compound content, phytohormones, enzymatic activities (i.e., starch phosphorylases, α- and β-amylase), and starch granules. The results indicated that the starch metabolism in banana fruit ripening is affected by BLSD infection. Fruit from infested plots contained unusual amounts of soluble sugars in the green stage and smaller starch granules and showed a different pattern of superficial degradation. Enzymatic activities linked to starch degradation were also altered by the disease. Moreover, the levels of indole-acetic acid and phenolic compounds indicated an advanced fruit physiological age for fruits from infested plots.

In-vitro starch hydrolysis of chitosan incorporating whey protein and wheat starch composite gels

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Natasha Yang

2017-10-01

Full Text Available The study examined the influence of chitosan, incorporated into whey protein and wheat starch thermo gels, on the in-vitro hydrolysis of the polysaccharide. Gels were subjected to the following external conditions containing α-amylase at constant incubation temperature of 37 °C: In the first procedure, they were immersed in phosphate buffer (0.05 M and maintained at pH 6.9 throughout the entire digestion. In the second instance, they were introduced into a salt solution, with pH and total volume adjusted at times in sync with the human gastrointestinal tract. Results indicate that low and medium molecular weight chitosan, in combination with whey protein, were effective at enhancing the protective barrier against starch degradation. Less maltose was liberated from gels containing medium molecular weight chitosan, as opposed to the low molecular weight counterpart, and results compare favorably with the outcome of the in-vitro digestion of binary whey protein and wheat starch composites. Keywords: Food science

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. Copyright © 2015 Elsevier B.V. All rights reserved.

In vitro fermentability of differently digested resistant starch preparations

NARCIS (Netherlands)

Fässler, C.; Arrigoni, E.; Venema, K.; Brouns, F.; Amadò, R.

2006-01-01

The in vitro fermentability of two resistant starch preparations type 2 (RS2) and type 3 (RS3) was investigated using human colonic microbiota. Prior to the fermentation experiments, samples were digested using two in vitro models, a batch (ba) and a dynamic (dy), as well as an in vivo method (il)

Chemical characteristic and functional properties of arenga starch-taro (Colocasia esculanta L.) flour noodle with turmeric extracts addition

Science.gov (United States)

Ervika Rahayu N., H.; Ariani, Dini; Miftakhussolikhah, E., Maharani P.; Yudi, P.

2017-01-01

Arenga starch-taro (Colocasia esculanta L.) flour noodle is an alternative carbohydrate source made from 75% arenga starch and 25% taro flour, but it has a different color with commercial noodle product. The addition of natural color from turmeric may change the consumer preference and affect chemical characteristic and functional properties of noodle. This research aims to identify chemical characteristic and functional properties of arenga starch-taro flour noodle with turmeric extract addition. Extraction was performed using 5 variances of turmeric rhizome (0.06; 0.12; 0.18; 0.24; and 0.30 g (fresh weight/ml water). Then, noodle was made and chemical characteristic (proximate analysis) as well as functional properties (amylose, resistant starch, dietary fiber, antioxidant activity) were then evaluated. The result showed that addition of turmeric extract did not change protein, fat, carbohydrate, amylose, and resistant starch content significantly, while antioxidant activity was increased (23,41%) with addition of turmeric extract.

Enzymatic Properties of an Alkaline and Chelator Resistant alpha-amylase from the Alkaliphilic Bacillus sp. Isolate L1711

Science.gov (United States)

Bernhardsdotter, Eva C. M. J.; Pusey, Marc L.; Ng, Joseph D.; Garriott, Owen K.

2004-01-01

An alkaliphilic amylase producing bacterium, Bacillus sp. strain L 711, was selected among 13 soda lakes isolates. When grown at pH 10.5 and 37 C, strain L711 produced multiple forms of amylases in the culture broth. One of these, BAA, was purified from the culture supernatant by QAE column chromatography and preparative native gel electrophoresis. The molecular weight of BAA was determined to be 51 kDa by denaturing gel electrophoresis. The pH optima for activity below and above 40 C were 9.5 - 10.0 and 7.0 - 7.5 respectively. BAA was stable in the pH range 6-11 and was completely inactivated at 55 C. The thermostability was not increased in the presence of Ca(2+). The enzyme was strongly inhibited by Ca(2+), Zn(2+), Mg(2+), Mn(2+), Ba(2+) and Cu(2+), whereas the presence of Na(+), Co(2+) and EDTA (10 mM) enhanced enzymatic activity. The K(sub m), and specific activity of BAA on soluble starch were 1.9 mg/ml and 18.5 U/mg respectively. The main end products of hydrolysis were maltotetraose, maltose and glucose.

Effect of gamma radiation on the activity of alpha and beta amylases in germinating fenugreek (Trigonella foenum-Graceum, L.) beans

International Nuclear Information System (INIS)

Yacoub, N.J.

1978-01-01

In previous experiments, three weeks old cotyledons from gamma irradiated seeds of fenugreek beans were observed to be healthier and heavier than their non-irradiated controls. A hypothesis was set that this phenomenon was due to the accumulation of carbohydrate in the cotyledons. To test this hypothesis an experiment was designed to determine the sugars and starch contents in the cotyledons of an irradiated and nonirradiated groups at different stages of development. At the same time the amylases activities in the same groups were assayed. Results indicated that there was actually increased amount of sugars ad starch in the two and three week old cotyledons of the irradiated as compared to their controls group. These findings support the above hypothesis. The amylase activities were also higher in the irradiated groups as compared to their non-irradiated controls. These results suggest that irradiation induced stimulation of the photosynthetic rate, and amylases' activities, meanwhile, slowed the translocation of carbohydrate nutrients from the cotyledons into the growing seedlings

Survival of resistant starch during the processing of atmospheric and vacuum fried instant noodles

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Maria Gabriela VERNAZA

Full Text Available Abstract The objective was to develop instant noodles (IN made by atmospheric and vacuum frying processes, with addition of 10% of three different sources of resistant starch: resistant starch type 2 (RS2, resistant starch type 3 (RS3 and green banana flour (GBF aiming the increasing of the fibre content. The IN obtained by atmospheric frying lost water faster and absorbed more fat. However, for both frying treatments, the RS3 noodles absorbed the least amount of oil. The greatest loss of RS occurred during the cooking stage. RS2 and GBF noodles presented a loss of RS of around 30% during steam cooking, while the RS3 approximately 18%. The frying process decreased RS content of noodles, however, during both frying process, the samples with the highest RS content at all frying times were noodles containing RS3. When comparing products obtained after 90 and 120 s of atmospheric and vacuum frying, respectively, it was observed that, although the frying time in vacuum process was longer, higher RS values were obtained for the three different formulations. The vacuum frying process has advantages due to the lower fat absorption (3% less, lighter colour and a reduced conversion of RS to digestible starch, compared to atmospheric frying.

Nutritional strategies to combat physiological imbalance of dairy cows during early lactation: The effect of changes in dietary protein to starch-ratios

DEFF Research Database (Denmark)

Moyes, Kasey; Friggens, Nic; Ingvartsen, Klaus Lønne

2010-01-01

Thirty Danish Holstein cows were used to determine how cows in early lactation adapt to changes in protein to starch supply in order to manipulate metabolism to combat physiological imbalance. During weeks 4 through 6 of lactation, 10 cows were fed either a high protein to starch ratio (high) diet...... for the low, control and high diets, respectively. Besides milk urea nitrogen, no other production or metabolic parameters were affected by treatment. In conclusion, manipulation of dietary protein to starch is not a potential strategy to combat physiological imbalance during early lactation...

Antimicrobial lysozyme-containing starch microgel to target and inhibit amylase-producing microorganisms

NARCIS (Netherlands)

Li, Y.; Kadam, S.; Abee, T.; Slaghek, T.M.; Timmermans, J.W.; Cohen Stuart, M.A.; Norde, W.; Kleijn, M.J.

2012-01-01

The aim of this study is to determine the release of lysozyme from oxidized starch microgels and subsequently test its antimicrobial activity. The gels are made of oxidized potato starch polymers, which are chemically cross-linked by sodium trimetaphosphate (STMP). The microgel is negatively charged

Effect of aspirin or resistant starch on colorectal neoplasia in the Lynch syndrome.

Science.gov (United States)

Burn, John; Bishop, D Timothy; Mecklin, Jukka-Pekka; Macrae, Finlay; Möslein, Gabriela; Olschwang, Sylviane; Bisgaard, Marie-Luise; Ramesar, Raj; Eccles, Diana; Maher, Eamonn R; Bertario, Lucio; Jarvinen, Heikki J; Lindblom, Annika; Evans, D Gareth; Lubinski, Jan; Morrison, Patrick J; Ho, Judy W C; Vasen, Hans F A; Side, Lucy; Thomas, Huw J W; Scott, Rodney J; Dunlop, Malcolm; Barker, Gail; Elliott, Faye; Jass, Jeremy R; Fodde, Ricardo; Lynch, Henry T; Mathers, John C

2008-12-11

Observational and epidemiologic data indicate that the use of aspirin reduces the risk of colorectal neoplasia; however, the effects of aspirin in the Lynch syndrome (hereditary nonpolyposis colon cancer) are not known. Resistant starch has been associated with an antineoplastic effect on the colon. In a randomized, placebo-controlled trial, we used a two-by-two design to investigate the effects of aspirin, at a dose of 600 mg per day, and resistant starch (Novelose), at a dose of 30 g per day, in reducing the risk of adenoma and carcinoma among persons with the Lynch syndrome. Among 1071 persons in 43 centers, 62 were ineligible to participate in the study, 72 did not enter the study, and 191 withdrew from the study. These three categories were equally distributed across the study groups. Over a mean period of 29 months (range, 7 to 74), colonic adenoma or carcinoma developed in 141 participants. Of 693 participants randomly assigned to receive aspirin or placebo, neoplasia developed in 66 participants receiving aspirin (18.9%), as compared with 65 receiving placebo (19.0%) (relative risk, 1.0; 95% confidence interval [CI], 0.7 to 1.4). There were no significant differences between the two groups with respect to the development of advanced neoplasia (7.4% and 9.9%, respectively; P=0.33). Among the 727 participants receiving resistant starch or placebo, neoplasia developed in 67 participants receiving starch (18.7%), as compared with 68 receiving placebo (18.4%) (relative risk, 1.0; 95% CI, 0.7 to 1.4). Advanced adenomas and colorectal cancers were evenly distributed in the two groups. The prevalence of serious adverse events was low, and the events were evenly distributed. The use of aspirin, resistant starch, or both for up to 4 years has no effect on the incidence of colorectal adenoma or carcinoma among carriers of the Lynch syndrome. (Current Controlled Trials number, ISRCTN59521990.) 2008 Massachusetts Medical Society

Enzymatic Production of Ethanol from Cassava Starch Using Two ...

African Journals Online (AJOL)

Cassava starch from TMS 30572 and Idileru were hydrolyzed with ƒ¿-amylase and amylo-glucosidase before fermentation using two strains of Saccharomyces cerevisiae from palm wine and bakersf yeast. The per cent yield of sugars and total dissolved solids were 66 % and 26% respectively while pH was 7.

Evaluation of Traditional Indian Antidiabetic Medicinal Plants for Human Pancreatic Amylase Inhibitory Effect In Vitro

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Sudha Ponnusamy

2011-01-01

Full Text Available Pancreatic α-amylase inhibitors offer an effective strategy to lower the levels of post prandial hyperglycemia via control of starch breakdown. Eleven Ayurvedic Indian medicinal plants with known hypoglycemic properties were subjected to sequential solvent extraction and tested for α-amylase inhibition, in order to assess and evaluate their inhibitory potential on pancreatic α-amylase. Analysis of 91 extracts, showed that 10 exhibited strong Human Pancreatic Amylase (HPA inhibitory potential. Of these, 6 extracts showed concentration dependent inhibition with IC50 values, namely, cold and hot water extracts from Ficus bengalensis bark (4.4 and 125 μgmL-1, Syzygium cumini seeds (42.1 and 4.1 μgmL-1, isopropanol extracts of Cinnamomum verum leaves (1.0 μgmL-1 and Curcuma longa rhizome (0.16 μgmL-1. The other 4 extracts exhibited concentration independent inhibition, namely, methanol extract of Bixa orellana leaves (49 μgmL-1, isopropanol extract from Murraya koenigii leaves (127 μgmL-1, acetone extracts from C. longa rhizome (7.4 μgmL-1 and Tribulus terrestris seeds (511 μgmL-1. Thus, the probable mechanism of action of the above fractions is due to their inhibitory action on HPA, thereby reducing the rate of starch hydrolysis leading to lowered glucose levels. Phytochemical analysis revealed the presence of alkaloids, proteins, tannins, cardiac glycosides, flavonoids, saponins and steroids as probable inhibitory compounds.

Wheat bran as a substrate for thermo stable alpha-amylase production by gamma irradiated bacillus megaterium in solid state fermentation

International Nuclear Information System (INIS)

ElVatal, A.I.; Khalaf, M.A.

2003-01-01

Thermo stable alpha-amylase (EC 3.2.1.1) production from cheap agriculture-industrial waste wheat bran (WB) medium by superior potent gamma irradiated locally isolated strain of Bacillus megaterium in solid state fermentation (SSF) was studied. A highly yielding, stable enhanced isolated strain of bacillus megaterium in solid state fermentation (SSF) was studied. A highly yielding stable enhanced isolate B. megaterium- gamma 21F derived from the 10 kGy, treatment, exhibited the highest alpha-amylase activity under SSF, with 2.8 fold more enzyme titer as compared to the unirradiated wild strain. A vancomycin (Vm) resistant gamma irradiated enhanced isolate B. megaterium-gamma 21F2 (which was selected throughout the subsequent work) secreted (1.27 and 3.58) folds superior titers of alpha-amylase than the gamma irradiated parent isolate (B.megaterium -gamma21F) and unirradiated wild strain, respectively under SSF process. The effects of various parameters, such as moistening agent, initial moisture content level, initial ph, incubation temperature, inoculum size and incubation time on thermo stable alpha-amylase production by B.megaterium-gamma 21F2 under SSF were studied. Maximum enzyme production was recorded in WB medium moistened with (1:2, w/v) distilled water at initial ph (7.0) and inoculated with (2.24 x 10 8 cells/g WB) after 48 h incubation at 40 C degree. Between different solvents used for enzyme extraction from fermented WB mass, distilled water at ph (7.0) was the superior efficient leaching solvent. The specific activity of the precipitated partially purified crude thermo stable enzyme was (258.7 U/mg protein) with ph optima (6.5-7.0), at optimal temperatures (65-70 c degree) and it retained about 53% of its maximum activity after 12 h incubation at 70 c degree. The partially purified crude enzyme was used for starch digestion (5%0 under optimized reaction conditions, wherein (98.2%) starch hydrolysis was attained after 6 h

[Effect of extrusion on protein and starch bioavailability in corn and lima bean flour blends].

Science.gov (United States)

Pérez-Navarrete, Cecilia; Betancur-Ancona, David; Casotto, Meris; Carmona, Andrés; Tovar, Juscelino

2007-09-01

Extrusion is used to produce crunchy expanded foods, such as snacks. The nutritional impact of this process has not been studied sufficiently. In this study, in vitro and in vivo protein and starch bioavailability was evaluated in both raw and extruded corn (Zea mays)(C) and lima bean (Phaseolus lunatus)(B) flour blends, prepared in 75C/25B and 50C/ 50B (p/p) proportions. These were processed with a Brabender extruder at 160 degrees C, 100 rpm and 15.5% moisture content. Proximate composition showed that in the extruded products protein and ash contents increased whereas the fat level decreased. In vitro protein digestibility was higher in the extrudates (82%) than in the raw flours (77%). Potentially available starch and resistant starch contents decreased with extrusion. The in vitro assays indicated that extrusion improved protein and starch availability in the studied blends. In vivo bioavailability was evaluated using the rice weevil (Sithophilus oryzae) as a biological model. The most descriptive biomarkers of the changes suggested by the in vivo tests were body protein content (increased by extrusion) and intestinal a-amylase activity (decreased by processing). Overall, results suggest that extrusion notably increases the nutritional quality of corn and lima bean flour blends.

Starch bioengineering

DEFF Research Database (Denmark)

Blennow, Andreas

2018-01-01

Application of starch in industry frequently requires extensive modification. This is usually achieved by chemical and/or physical modification that is time-consuming and often expensive and polluting. To impart functionality as early as possible in the starch production chain, modification can...... be achieved directly as part of the developing starch storage roots, tubers, and seeds and grains of the crop. Starch has been a strong driver for human development and is now the most important energy provider in the diet forcing the development of novel and valuable starch qualities for specific...... applications. Among the most important structures that can be targeted include starch phosphorylation chain transfer/branching generating chemically substituted and chain length-modified starches such as resistant and health-promoting high-amylose starch. Starch bioengineering has been employed for more than...

Inhibitory effects of edible seaweeds, polyphenolics and alginates on the activities of porcine pancreatic α-amylase

DEFF Research Database (Denmark)

Zaharudin, Nazikussabah Binti; Asunción Salmeán, Armando; Dragsted, Lars Ove

2018-01-01

Edible seaweeds are valuable because of their organoleptic properties and complex polysaccharide content. A study was conducted to investigate the potential of dried edible seaweed extracts, its potential phenolic compounds and alginates for α-amylase inhibitory effects. The kinetics of inhibition......,5-dihydroxybenzoic acid was found to be a potent inhibitor of α-amylase with an IC50 value of 0.046 ± 0.004 mg/ml. Alginates found in brown seaweeds appeared to be potent inhibitors of α-amylase activity with an IC50 of (0.075 ± 0.010–0.103 ± 0.017) mg/ml, also a mixed-type inhibition. Overall, the findings provide...... information that crude extracts of brown edible seaweeds, phenolic compounds and alginates are potent α-amylase inhibitors, thereby potentially retarding glucose liberation from starches and alleviation of postprandial hyperglycaemia....

Interaction of Salivary alpha-Amylase and Amylase-Binding-Protein A (AbpA of Streptococcus gordonii with Glucosyltransferase of S. gordonii and Streptococcus mutans

Directory of Open Access Journals (Sweden)

Tanzer Jason M

2007-06-01

Full Text Available Abstract Background Glucosyltransferases (Gtfs, enzymes that produce extracellular glucans from dietary sucrose, contribute to dental plaque formation by Streptococcus gordonii and Streptococcus mutans. The alpha-amylase-binding protein A (AbpA of S. gordonii, an early colonizing bacterium in dental plaque, interacts with salivary amylase and may influence dental plaque formation by this organism. We examined the interaction of amylase and recombinant AbpA (rAbpA, together with Gtfs of S. gordonii and S. mutans. Results The addition of salivary alpha-amylase to culture supernatants of S. gordonii precipitated a protein complex containing amylase, AbpA, amylase-binding protein B (AbpB, and the glucosyltransferase produced by S. gordonii (Gtf-G. rAbpA was expressed from an inducible plasmid, purified from Escherichia coli and characterized. Purified rAbpA, along with purified amylase, interacted with and precipitated Gtfs from culture supernatants of both S. gordonii and S. mutans. The presence of amylase and/or rAbpA increased both the sucrase and transferase component activities of S. mutans Gtf-B. Enzyme-linked immunosorbent assay (ELISA using anti-Gtf-B antibody verified the interaction of rAbpA and amylase with Gtf-B. A S. gordonii abpA-deficient mutant showed greater biofilm growth under static conditions than wild-type in the presence of sucrose. Interestingly, biofilm formation by every strain was inhibited in the presence of saliva. Conclusion The results suggest that an extracellular protein network of AbpA-amylase-Gtf may influence the ecology of oral biofilms, likely during initial phases of colonization.

Enzymatic Modification of Corn Starch Influences Human Fecal Fermentation Profiles.

Science.gov (United States)

Dura, Angela; Rose, Devin J; Rosell, Cristina M

2017-06-14

Enzymatically modified starches have been widely used in food applications to develop new products, but information regarding digestion and fecal fermentation of these products is sparse. The objective of this study was to determine the fermentation properties of corn starch modified with α-amylase, amyloglucosidase, or cyclodextrin glycosyltransferase and the possible role of hydrolysis products. Samples differed in their digestibility and availability to be fermented by the microbiota, resulting in differences in microbial metabolites produced during in vitro fermentation. The presence or absence of hydrolysis products and gelatinization affected starch composition and subsequent metabolite production by the microbiota. Amyloglucosidase-treated starch led to the greatest production of short- and branched-chain fatty acid production by the microbiota. Results from this study could be taken into consideration to confirm the possible nutritional claims and potential health benefits of these starches as raw ingredients for food development.

Lactucaxanthin - a potential anti-diabetic carotenoid from lettuce (Lactuca sativa) inhibits α-amylase and α-glucosidase activity in vitro and in diabetic rats.

Science.gov (United States)

Gopal, Sowmya Shree; Lakshmi, Magisetty Jhansi; Sharavana, Gurunathan; Sathaiah, Gunaseelan; Sreerama, Yadahally N; Baskaran, Vallikannan

2017-03-22

Intestinal and pancreatic α-amylase and α-glucosidase inhibitors offer an approach to lower the levels of post-prandial hyperglycemia through the control of dietary starch breakdown in digestion. This study hypothesized that lactucaxanthin (Lxn) in lettuce (Lactuca sativa) inhibits the activity of α-amylase and α-glucosidase. In this study, the interaction of Lxn with α-amylase and α-glucosidase in silico and its inhibitory effect on these enzymes were studied using in vitro and STZ-induced diabetic rat models. Lxn was isolated from lettuce with 96% purity confirmed by HPLC and LCMS. The in silico analysis showed that Lxn has a lower binding energy (-6.05 and -6.34 kcal mol -1 ) with α-amylase and α-glucosidase compared to their synthetic inhibitors, acarbose (-0.21 kcal mol -1 ) and miglitol (-2.78 kcal mol -1 ), respectively. In vitro α-amylase and α-glucosidase inhibition assays revealed that Lxn had IC 50 values of 435.5 μg mL -1 and 1.84 mg mL -1 , but acarbose has values of 2.5 and 16.19 μg mL -1 . The in vivo results showed an increased activity for α-amylase and α-glucosidase in the intestine (4.7 and 1.30 fold, p < 0.05) and pancreas (1.3 and 1.48 fold, p < 0.05) of STZ induced diabetic rats compared to normal rats. Whereas the activity decreased (p < 0.05) in the Lxn fed diabetic rats, except for the intestinal α-glucosidase activity (1.69 ± 0.12 PNP per min per mg protein). This was confirmed by the low blood glucose level (239.4 ± 18.2 mg dL -1 ) in diabetic rats fed Lxn compared to the diabetic group (572.2 ± 30.5 mg dL -1 , p < 0.05). Lxn significantly inhibited (p < 0.05) the activity of α-amylase and α-glucosidase and could be of medical and nutritional relevance in the treatment of diabetes.

Selective sweep on human amylase genes postdates the split with Neanderthals

Science.gov (United States)

Inchley, Charlotte E.; Larbey, Cynthia D. A.; Shwan, Nzar A. A.; Pagani, Luca; Saag, Lauri; Antão, Tiago; Jacobs, Guy; Hudjashov, Georgi; Metspalu, Ene; Mitt, Mario; Eichstaedt, Christina A.; Malyarchuk, Boris; Derenko, Miroslava; Wee, Joseph; Abdullah, Syafiq; Ricaut, François-Xavier; Mormina, Maru; Mägi, Reedik; Villems, Richard; Metspalu, Mait; Jones, Martin K.; Armour, John A. L.; Kivisild, Toomas

2016-01-01

Humans have more copies of amylase genes than other primates. It is still poorly understood, however, when the copy number expansion occurred and whether its spread was enhanced by selection. Here we assess amylase copy numbers in a global sample of 480 high coverage genomes and find that regions flanking the amylase locus show notable depression of genetic diversity both in African and non-African populations. Analysis of genetic variation in these regions supports the model of an early selective sweep in the human lineage after the split of humans from Neanderthals which led to the fixation of multiple copies of AMY1 in place of a single copy. We find evidence of multiple secondary losses of copy number with the highest frequency (52%) of a deletion of AMY2A and associated low copy number of AMY1 in Northeast Siberian populations whose diet has been low in starch content. PMID:27853181

Solid-state fermentation of cornmeal with the basidiomycete Hericium erinaceum for degrading starch and upgrading nutritional value.

Science.gov (United States)

Han, Jianrong

2003-01-15

The ability of the basidiomycete Hericium erinaceum to degrade starch and upgrade nutritional value of cornmeal during solid-state fermentation was studied. On the basal medium which consisted of cornmeal and salt solution, H. erinaceum produced a strong alpha-amylase on the 15th day after inoculation, which resulted in a 52% degradation of the starch. By supplementation with 5-15 g soybean meal per 100 g cornmeal the alpha-amylase activity and degradation rate of starch was raised significantly (P cornmeal, the starch content in the product decreased from 63% to 22% (P < 0.001) and protein content increased from 12% to 17% (P < 0.01). In the protein in the product, the lysine content was increased from 36 to 56 mg/ g and tryptophan from 9 to 13 mg/g. Using egg protein as a standard, an evaluation on the protein quality of the fermented product showed that it was superior to that of the nonfermented control and to other cereals, was close to that of soybean and chicken, but was inferior to that of milk and red meats.

Hydrolysis of wheat B-starch and characterisation of acetylated maltodextrin

Czech Academy of Sciences Publication Activity Database

Smrčková, P.; Horský, Jiří; Šárka, E.; Koláček, J.; Netopilík, Miloš; Walterová, Zuzana; Kruliš, Zdeněk; Synytsya, A.; Hrušková, K.

2013-01-01

Roč. 98, č. 1 (2013), s. 43-49 ISSN 0144-8617 R&D Projects: GA ČR GA525/09/0607 Institutional research plan: CEZ:AV0Z40500505 Keywords : wheat B-starch * α-amylase * acetylated maltodextrin Subject RIV: JI - Composite Materials Impact factor: 3.916, year: 2013

Alternative method for quantification of alfa-amylase activity Alternativa para quantificação de alfa-amilase

OpenAIRE

DF. Farias; AFU. Carvalho; CC. Oliveira; NM. Sousa; LCB. Rocha-Bezerrra; PMP. Ferreira; GPG. Lima; DC. Hissa

2010-01-01

A modification of the sensitive agar diffusion method was developed for macro-scale determination of alfa-amylase. The proposed modifications lower costs with the utilisation of starch as substrate and agar as supporting medium. Thus, a standard curve was built using alfa-amylase solution from Aspergillus oryzae, with concentrations ranging from 2.4 to 7,500 U.mL-1. Clear radial diffusion zones were measured after 4 hours of incubation at 20 °C. A linear relationship between the logarithm of...

Effects of microbial enzymes on starch and hemicellulose degradation in total mixed ration silages

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Tingting Ning

2017-02-01

Full Text Available Objective This study investigated the association of enzyme-producing microbes and their enzymes with starch and hemicellulose degradation during fermentation of total mixed ration (TMR silage. Methods The TMRs were prepared with soybean curd residue, alfalfa hay (ATMR or Leymus chinensis hay (LTMR, corn meal, soybean meal, vitamin-mineral supplements, and salt at a ratio of 25:40:30:4:0.5:0.5 on a dry matter basis. Laboratory-scale bag silos were randomly opened after 1, 3, 7, 14, 28, and 56 days of ensiling and subjected to analyses of fermentation quality, carbohydrates loss, microbial amylase and hemicellulase activities, succession of dominant amylolytic or hemicellulolytic microbes, and their microbial and enzymatic properties. Results Both ATMR and LTMR silages were well preserved, with low pH and high lactic acid concentrations. In addition to the substantial loss of water soluble carbohydrates, loss of starch and hemicellulose was also observed in both TMR silages with prolonged ensiling. The microbial amylase activity remained detectable throughout the ensiling in both TMR silages, whereas the microbial hemicellulase activity progressively decreased until it was inactive at day 14 post-ensiling in both TMR silages. During the early stage of fermentation, the main amylase-producing microbes were Bacillus amyloliquefaciens (B. amyloliquefaciens, B. cereus, B. licheniformis, and B. subtilis in ATMR silage and B. flexus, B. licheniformis, and Paenibacillus xylanexedens (P. xylanexedens in LTMR silage, whereas Enterococcus faecium was closely associated with starch hydrolysis at the later stage of fermentation in both TMR silages. B. amyloliquefaciens, B. licheniformis, and B. subtilis and B. licheniformis, B. pumilus, and P. xylanexedens were the main source of microbial hemicellulase during the early stage of fermentation in ATMR and LTMR silages, respectively. Conclusion The microbial amylase contributes to starch hydrolysis during the

Copy number variation in salivary amylase: A participant-based study on genetic variation.

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Phillips, E.

2017-07-01

Full Text Available Amylase (AMY1 is an enzyme found in the mouth that is used to help digest carbohydrates. It has been found that the copy number of AMY1 has been positively associated with protein levels within an individual and also that individual’s population. This information can correspond to the positive ancestral linkage of high starch consumption within agricultural and hunter-gatherer societies. A high starch consumption means that the AMY1 enzyme will be more prevalent within their bodies, and the presence of AMY1 could both help bodies process starches better and prevent future conditions or intestinal diseases. The amylase gene is conclusively connected to the AMY1 copy number production. I hypothesized that individuals within a population will have a similar copy number of the AMY1 gene to each other. Twenty-five high school students located in Norman, Oklahoma were asked to retrieve buccal swabs from the inside of their cheek. DNA then was abstracted from these samples, and a quantitative polymerase chain reaction (qPCR, a machine used to detect the amount of genetic material found in the DNA, was completed in order to determine the copy number within each salivary sample. The qPCR was completed two different times in order to ensure correct results when the data was presented. Results indicated that the copy number within the population were similar to each other, and ranged from 1-12. This means that individuals located in this population have a lower production of amylase, and this provides indication that they are more likely to become obese than in previous research papers located in Arizona. Research shows that a smaller production of AMY1 may contribute to the chances of obesity in the future.

Lytic polysaccharide monooxygenases and other oxidative enzymes are abundantly secreted by Aspergillus nidulans grown on different starches

DEFF Research Database (Denmark)

Nekiunaite, Laura; Arntzen, Magnus Ø.; Svensson, Birte

2016-01-01

of Aspergillus nidulans grown on cereal starches from wheat and high-amylose (HA) maize, as well as legume starch from pea for 5 days. Aspergillus nidulans grew efficiently on cereal starches, whereas growth on pea starch was poor. The secretomes at days 3-5 were starch-type dependent as also reflected...... by amylolytic activity measurements. Nearly half of the 312 proteins in the secretomes were carbohydrate-active enzymes (CAZymes), mostly glycoside hydrolases (GHs) and oxidative auxiliary activities (AAs). The abundance of the GH13 α-amylase (AmyB) decreased with time, as opposed to other starch...

Salivary alpha-amylase : a measure associated with satiety and subsequent food intake in humans

NARCIS (Netherlands)

Harthoorn, L.F.

2008-01-01

Food intake regulation in humans involves various central and peripheral mechanisms. In this study salivary -amylase was examined for functioning as a measure of satiety and food intake. In a 1.25-h session, 32 fasted subjects were given a preload of starch-based custard (849 kJ) followed by ad

Intake of total dietary sugar and fibre is associated with insulin resistance among Danish 8-10- and 14-16-year-old girls but not boys. European Youth Heart Studies I and II

DEFF Research Database (Denmark)

Kynde, Iben; Johnsen, Nina Føns; Wedderkopp, Niels

2010-01-01

Objective: To examine the dietary intake of total sugar, added sugar, non-added sugar and starch as well as dietary fibre and glycaemic index (GI) and their respective associations with insulin resistance. Design: Mixed linear models were used to study both cross-sectional and prospective...... associations between carbohydrate components and insulin resistance separately in girls and boys. Diet was assessed by a single 24 h recall interview and insulin resistance was calculated using the homoestasis model assessment (HOMA). Setting: The Danish part of the European Youth Heart Studies (EYHS) I and II....... Subjects: Girls and boys at 8–10 and 14–16 years from EYHS I (n 651) and 8–10-year olds from baseline followed up 6 years later in EYHS II (n 233). Results: Among girls, a difference in dietary total sugar of 43 g/MJ was associated with a 1 SD difference of HOMA and a difference in dietary fibre of 28g...

Starches, Sugars and Obesity

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Erik E. J. G. Aller

2011-03-01

Full Text Available The rising prevalence of obesity, not only in adults but also in children and adolescents, is one of the most important public health problems in developed and developing countries. As one possible way to tackle obesity, a great interest has been stimulated in understanding the relationship between different types of dietary carbohydrate and appetite regulation, body weight and body composition. The present article reviews the conclusions from recent reviews and meta-analyses on the effects of different starches and sugars on body weight management and metabolic disturbances, and provides an update of the most recent studies on this topic. From the literature reviewed in this paper, potential beneficial effects of intake of starchy foods, especially those containing slowly-digestible and resistant starches, and potential detrimental effects of high intakes of fructose become apparent. This supports the intake of whole grains, legumes and vegetables, which contain more appropriate sources of carbohydrates associated with reduced risk of cardiovascular and other chronic diseases, rather than foods rich in sugars, especially in the form of sugar-sweetened beverages.

Influence of dietary starch and cellulose levels on the metabolic profile and apparent digestibility in penaeoid shrimp Influencia del nivel de almidón y celulosa en la dieta sobre el perfil metabólico y digestibilidad aparente en camarones penaeoideos

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Susana María Velurtas

2011-07-01

Full Text Available The present study compared the effect of different starch/cellulose ratios (30/0, 20/10, 10/20, 0/30 on the metabolic response and apparent digestibility in two species of penaeoids: Artemesia longinaris and Pleoticus muelleri. Adult animals were used in order to obtain sufficient quantities of haemolymph and faecal material for analysis. No significant differences were found in levels of plasma metabolites in P. muelleri, but in A. longinaris, a significant increase was observed in glucose, total protein, and cholesterol in correlation with increased dietary starch. The apparent digestibility coefficients decreased from 83.7% to 51.2% (A. longinaris and from 71.9% to 7.6% (P. muelleri as the dietary starch levels increased. The ratio of amylase activity to protease activity (A/P ratio declined in A. longinaris when the percentage of dietary starch increased. In contrast, the A/P ratio for P. muelleri increased with higher starch concentrations. These results demonstrated a close relationship between the feeding habits and digestive physiology of the two species studied; they also suggest a more herbivorous behavior for A. longinaris and more omnivorous habits for P. muelleri.En el presente estudio se comparó el efecto de diferentes concentraciones de almidón/celulosa (30/0; 20/10; 10/20; 0/30 sobre la respuesta metabólica y la digestibilidad aparente en dos especies de peneidos, Artemesia longinaris y Pleoticus muelleri. Se utilizaron animales adultos a fin de obtener cantidades suficientes de hemolinfa y heces para los análisis. No hubo diferencias significativas en los niveles de metabolitos plasmáticos en P. muelleri, en cambio en A. longinaris se observó un incremento significativo de la glucosa, proteínas totales y colesterol en relación con el aumento del almidón en la dieta. Los coeficientes de digestibilidad aparente disminuyeron de 83,7% a 51,2% (A. longinaris y de 71,9% a 7,6% (P. muelleri a medida que los porcentajes de

Production of starch with antioxidative activity by baking starch with organic acids.

Science.gov (United States)

Miwa, Shoji; Nakamura, Megumi; Okuno, Michiko; Miyazaki, Hisako; Watanabe, Jun; Ishikawa-Takano, Yuko; Miura, Makoto; Takase, Nao; Hayakawa, Sachio; Kobayashi, Shoichi

2011-01-01

A starch ingredient with antioxidative activity, as measured by the DPPH method, was produced by baking corn starch with an organic acid; it has been named ANOX sugar (antioxidative sugar). The baking temperature and time were fixed at 170 °C and 60 min, and the organic acid used was selected from preliminary trials of various kinds of acid. The phytic acid ANOX sugar preparation showed the highest antioxidative activity, but the color of the preparation was almost black; we therefore selected L-tartaric acid which had the second highest antioxidative activity. The antioxidative activity of the L-tartaric acid ANOX sugar preparation was stable against temperature, light, and enzyme treatments (α-amylase and glucoamylase). However, the activity was not stable against variations in water content and pH value. The antioxidative activity of ANOX sugar was stabilized by treating with boiled water or nitrogen gas, or by pH adjustment.

Effect of aspirin or resistant starch on colorectal neoplasia in the Lynch syndrome

DEFF Research Database (Denmark)

Burn, John; Bishop, D Timothy; Mecklin, Jukka-Pekka

2008-01-01

BACKGROUND: Observational and epidemiologic data indicate that the use of aspirin reduces the risk of colorectal neoplasia; however, the effects of aspirin in the Lynch syndrome (hereditary nonpolyposis colon cancer) are not known. Resistant starch has been associated with an antineoplastic effect...... on the colon. METHODS: In a randomized, placebo-controlled trial, we used a two-by-two design to investigate the effects of aspirin, at a dose of 600 mg per day, and resistant starch (Novelose), at a dose of 30 g per day, in reducing the risk of adenoma and carcinoma among persons with the Lynch syndrome...... on the incidence of colorectal adenoma or carcinoma among carriers of the Lynch syndrome. (Current Controlled Trials number, ISRCTN59521990.)...

Effects of ruminally degradable starch levels on performance, nitrogen balance, and nutrient digestibility in dairy cows fed low corn-based starch diets

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Guobin Luo

2017-05-01

Full Text Available Objective This trial was performed to examine the effects of ruminally degradable starch (RDS levels in total mixed ration (TMR with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Methods Eight multiparous Holstein cows (body weight [BW]: 717±63 kg; days in milk [DIM]: 169±29 were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS or 72.1% ruminally degradable starch (% of total starch, high RDS. Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component. Results The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR. Conclusion Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.

High amylose resistant starch diet ameliorates oxidative stress, inflammation, and progression of chronic kidney disease.

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Nosratola D Vaziri

Full Text Available Inflammation is a major mediator of CKD progression and is partly driven by altered gut microbiome and intestinal barrier disruption, events which are caused by: urea influx in the intestine resulting in dominance of urease-possessing bacteria; disruption of epithelial barrier by urea-derived ammonia leading to endotoxemia and bacterial translocation; and restriction of potassium-rich fruits and vegetables which are common sources of fermentable fiber. Restriction of these foods leads to depletion of bacteria that convert indigestible carbohydrates to short chain fatty acids which are important nutrients for colonocytes and regulatory T lymphocytes. We hypothesized that a high resistant starch diet attenuates CKD progression. Male Sprague Dawley rats were fed a chow containing 0.7% adenine for 2 weeks to induce CKD. Rats were then fed diets supplemented with amylopectin (low-fiber control or high fermentable fiber (amylose maize resistant starch, HAM-RS2 for 3 weeks. CKD rats consuming low fiber diet exhibited reduced creatinine clearance, interstitial fibrosis, inflammation, tubular damage, activation of NFkB, upregulation of pro-inflammatory, pro-oxidant, and pro-fibrotic molecules; impaired Nrf2 activity, down-regulation of antioxidant enzymes, and disruption of colonic epithelial tight junction. The high resistant starch diet significantly attenuated these abnormalities. Thus high resistant starch diet retards CKD progression and attenuates oxidative stress and inflammation in rats. Future studies are needed to explore the impact of HAM-RS2 in CKD patients.

Enzymatic conversion of starch in twin-screw HTST-extruder

Energy Technology Data Exchange (ETDEWEB)

Hakulin, S; Linko, Y Y; Linko, P; Seiler, K; Seibel, W

1983-12-01

Wheat starch was liquefied to DE 25-30 employing heat stable ..cap alpha..-amylase and twin-screw Werner and Pfleiderer Continua 58 HTST-extruder. Most significant reduction in batch saccharification time was obtained when starch was liquefied as a slurry containing 60% water at 120/sup 0/C mass temperature, feed rate 1 500 g min/sup -1/, screw rotation rate 250 min/sup -1/, and 0.9% (w/w, d.s.) Novo Termamyl 120 L ..cap alpha..-amylase was added immediately after initiation of gelatinization in the extruder. Saccharification was carried out at 60/sup 0/C employing 0.36 (w/w, d.s.) Novo glucoamylase 150 L to reach a DE 96 in 22 h. Best total conversion was, however, obtained when also saccharification was initiated in the extruder by adding glucoamylase just before the die element, after lowering mass temperature to 60/sup 0/C, and by allowing the saccharification to continue at 60/sup 0/C after extrusion processing to reach a DE 94 in 5 h and DE 97 in 21 h.

Resistant starch and protein intake enhances fat oxidation and feelings of fullness in lean and overweight/obese women

DEFF Research Database (Denmark)

Gentile, Christopher L; Ward, Emery; Holst, Jens Juul

2015-01-01

and overweight/obese women. METHODS: Women of varying levels of adiposity consumed one of four pancake test meals in a single-blind, randomized crossover design: 1) waxy maize (control) starch (WMS); 2) waxy maize starch and whey protein (WMS+WP); 3) resistant starch (RS); or 4) RS and whey protein (RS...

Long branch-chains of amylopectin with B-type crystallinity in rice seed with inhibition of starch branching enzyme I and IIb resist in situ degradation and inhibit plant growth during seedling development : Degradation of rice starch with inhibition of SBEI/IIb during seedling development.

Science.gov (United States)

Pan, Ting; Lin, Lingshang; Wang, Juan; Liu, Qiaoquan; Wei, Cunxu

2018-01-08

Endosperm starch provides prime energy for cereal seedling growth. Cereal endosperm with repression of starch branching enzyme (SBE) has been widely studied for its high resistant starch content and health benefit. However, in barley and maize, the repression of SBE changes starch component and amylopectin structure which affects grain germination and seedling establishment. A high resistant starch rice line (TRS) has been developed through inhibiting SBEI/IIb, and its starch has very high resistance to in vitro hydrolysis and digestion. However, it is unclear whether the starch resists in situ degradation in seed and influences seedling growth after grain germination. In this study, TRS and its wild-type rice cultivar Te-qing (TQ) were used to investigate the seedling growth, starch property changes, and in situ starch degradation during seedling growth. The slow degradation of starch in TRS seed restrained the seedling growth. The starch components including amylose and amylopectin were simultaneously degraded in TQ seeds during seedling growth, but in TRS seeds, the amylose was degraded faster than amylopectin and the amylopectin long branch-chains with B-type crystallinity had high resistance to in situ degradation. TQ starch was gradually degraded from the proximal to distal region of embryo and from the outer to inner in endosperm. However, TRS endosperm contained polygonal, aggregate, elongated and hollow starch from inner to outer. The polygonal starch similar to TQ starch was completely degraded, and the other starches with long branch-chains of amylopectin and B-type crystallinity were degraded faster at the early stage of seedling growth but had high resistance to in situ degradation during TRS seedling growth. The B-type crystallinity and long branch-chains of amylopectin in TRS seed had high resistance to in situ degradation, which inhibited TRS seedling growth.

Quantitative digital image analysis of chromogenic assays for high throughput screening of alpha-amylase mutant libraries.

Science.gov (United States)

Shankar, Manoharan; Priyadharshini, Ramachandran; Gunasekaran, Paramasamy

2009-08-01

An image analysis-based method for high throughput screening of an alpha-amylase mutant library using chromogenic assays was developed. Assays were performed in microplates and high resolution images of the assay plates were read using the Virtual Microplate Reader (VMR) script to quantify the concentration of the chromogen. This method is fast and sensitive in quantifying 0.025-0.3 mg starch/ml as well as 0.05-0.75 mg glucose/ml. It was also an effective screening method for improved alpha-amylase activity with a coefficient of variance of 18%.

Molecular cloning and characterization of an α-amylase cDNA highly expressed in major feeding stages of the coffee berry borer, Hypothenemus hampei.

Science.gov (United States)

Bezerra, C A; Macedo, L L P; Amorim, T M L; Santos, V O; Fragoso, R R; Lucena, W A; Meneguim, A M; Valencia-Jimenez, A; Engler, G; Silva, M C M; Albuquerque, E V S; Grossi-de-Sa, M F

2014-12-10

α-Amylases are common enzymes responsible for hydrolyzing starch. Insect-pests, whose larvae develop in seeds, rely obligatorily on α-amylase activity to digest starch, as their major food source. Considering the relevance of insect α-amylases and the natural α-amylase inhibitors present in seeds to protect from insect damage, we report here the molecular cloning and nucleotide sequence of the full-length AmyHha cDNA of the coffee berry borer, Hypothenemus hampei, a major insect-pest of coffee crops. The AmyHha sequence has 1879 bp, containing a 1458 bp open reading frame, which encodes a predicted protein with 485 amino acid residues, with a predicted molecular mass of 51.2 kDa. The deduced protein showed 55-79% identity to other insect α-amylases, including Anthonomus grandis, Ips typographus and Sitophilus oryzae α-amylases. In depth analysis revealed that the highly conserved three amino acid residues (Asp184, Glu220, and Asp285), which compose the catalytic site are also presented in AmyHha amylase. The AmyHha gene seems to be a single copy in the haploid genome and AmyHha transcription levels were found higher in L2 larvae and adult insects, both corresponding to major feeding phases. Modeling of the AmyHha predicted protein uncovered striking structural similarities to the Tenebrio molitor α-amylase also displaying the same amino acid residues involved in enzyme catalysis (Asp184, Glu220 and Asp285). Since AmyHha gene was mostly transcribed in the intestinal tract of H. hampei larvae, the cognate α-amylase could be considered a high valuable target to coffee bean insect control by biotechnological strategies. Copyright © 2014. Published by Elsevier B.V.

Sixth taste – starch taste?

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Zygmunt Zdrojewicz

2017-06-01

Full Text Available Scientists from Oregon State University, USA, came up with the newest theory of the sixth taste – starch taste that might soon join the basic five tastes. This argument is supported by studies done on both animals and humans, the results of which seem to indicate the existence of separate receptors for starch taste, others than for sweet taste. Starch is a glucose homopolymer that forms an α-glucoside chain called glucosan or glucan. This polysaccharide constitutes the most important source of carbohydrates in food. It can be found in groats, potatoes, legumes, grains, manioc and corn. Apart from its presence in food, starch is also used in textile, pharmaceutical, cosmetic and stationery industries as well as in glue production. This polysaccharide is made of an unbranched helical structure – amylose (15–20%, and a structure that forms branched chains – amylopectin (80–85%. The starch structure, degree of its crystallisation or hydration as well as its availability determine the speed of food-contained starch hydrolysis by amylase. So far, starch has been considered tasteless, but the newest report shows that for people of different origins it is associated with various aliments specific for each culture. Apart from a number of scientific experiments using sweet taste inhibitors, the existence of the sixth taste is also confirmed by molecular studies. However, in order to officially include starch taste to the basic human tastes, it must fulfil certain criteria. The aim of the study is to present contemporary views on starch.

Optimization of maltodextrin production from avocado seed starch by response surface methodology

Science.gov (United States)

Nguyen, Thanh Viet; Ma, Tuyen-Hoang Nguyen; Nguyen, Tha Thi; Ho, Vinh-Nghi Kim; Vo, Hau Tan

2018-04-01

A process for maltodextrin production from avocado seed starch was reported in this study. Response surface methodology was used to investigate the effects of three independent variables for hydrolysis of the starch using a commercial food-grade α-amylase, Termamyl SC. These variables included enzyme concentration (0.05 - 0.15% starch), pH (5.0 - 6.0) and hydrolysis time (1.0 - 3.0 h), while the temperature fixed at 95°C. The result showed that the optimum conditions were using enzyme concentration at 0.12%, pH at 5.5 and 2.75 h of the incubation time. Under the optimum conditions, the recovered starch yield was 79.8% and the maltodextrin powder had 15.8 of dextrose equivalent.

Effects of a diet rich in arabinoxylan and resistant starch compared with a diet rich in refined carbohydrates on postprandial metabolism and features of the metabolic syndrome.

Science.gov (United States)

Schioldan, Anne Grethe; Gregersen, Søren; Hald, Stine; Bjørnshave, Ann; Bohl, Mette; Hartmann, Bolette; Holst, Jens Juul; Stødkilde-Jørgensen, Hans; Hermansen, Kjeld

2018-03-01

Low intake of dietary fibre is associated with the development of type 2 diabetes. Dyslipidaemia plays a key role in the pathogenesis of type 2 diabetes. Knowledge of the impact of dietary fibres on postprandial lipaemia is, however, sparse. This study aimed in subjects with metabolic syndrome to assess the impact on postprandial lipaemia and features of the metabolic syndrome of a healthy carbohydrate diet (HCD) rich in cereal fibre, arabinoxylan and resistant starch compared to a refined-carbohydrate western-style diet (WSD). Nineteen subjects completed the randomised, crossover study with HCD and WCD for 4-week. Postprandial metabolism was evaluated by a meal-challenge test and insulin sensitivity was assessed by HOMA-IR and Matsuda index. Furthermore, fasting cholesterols, serum-fructosamine, circulating inflammatory markers, ambulatory blood pressure and intrahepatic lipid content were measured. We found no diet effects on postprandial lipaemia. However, there was a significant diet × statin interaction on total cholesterol (P = 0.02) and LDL cholesterol (P = 0.002). HCD decreased total cholesterol (-0.72 mmol/l, 95% CI (-1.29; -0.14) P = 0.03) and LDL cholesterol (-0.61 mmol/l, 95% CI (-0.86; -0.36) P = 0.002) compared with WSD in subjects on but not without statin treatment. We detected no other significant diet effects. In subjects with metabolic syndrome on statins a 4-week diet rich in arabinoxylan and resistant starch improved fasting LDL and total cholesterol compared to subjects not being on statins. However, we observed no diet related impact on postprandial lipaemia or features of the metabolic syndrome. The dietary fibre x statin interaction deserves further elucidation.

Improvement of raw starch digestibility by ion-beam mutation of Aspergillus awamori

Energy Technology Data Exchange (ETDEWEB)

Amsal, Aryanti [National Atomic Energy Agency, Jakarta (Indonesia); Takigami, Machiko; Ito, Hitoshi

1998-09-01

Aspergillus awamori possess the ability to express raw starch digestibility. For the effective utilization of starchy crops produced in South-Asian countries, it is important to achieve the digestion of raw starchs for industrial fermentation process. In this study, higher ratio of mutant strains of Aspergillus awamori IFO4033 were isolated by irradiation of C{sup 5+} ion-beam on freeze dried spores with improvement of enzyme production for two-to threefold in the extracellular {alpha}-amylase compared with gamma-irradiation. The digestibility of raw starch from cassava, sago and sukun increased remarkably about two-to threefold by some mutant strains obtained from irradiation of C{sup 5+} ion-beam. (author)

Improvement of raw starch digestibility by ion-beam mutation of Aspergillus awamori

International Nuclear Information System (INIS)

Amsal, Aryanti; Takigami, Machiko; Ito, Hitoshi

1998-01-01

Aspergillus awamori possess the ability to express raw starch digestibility. For the effective utilization of starchy crops produced in South-Asian countries, it is important to achieve the digestion of raw starchs for industrial fermentation process. In this study, higher ratio of mutant strains of Aspergillus awamori IFO4033 were isolated by irradiation of C 5+ ion-beam on freeze dried spores with improvement of enzyme production for two-to threefold in the extracellular α-amylase compared with gamma-irradiation. The digestibility of raw starch from cassava, sago and sukun increased remarkably about two-to threefold by some mutant strains obtained from irradiation of C 5+ ion-beam. (author)

Biological studies on albino rats fed with Sorghum bicolor starch ...

African Journals Online (AJOL)

Partially purified amylase was extracted from the culture medium of Rhizopus sp. grown in potato dextrose broth for 48 h at room temperature by precipitation with 96.9% ethanol. The enzyme was used to hydrolyze sorghum starch. The hydrolyzed product was afterwards formulated into rat feed, which was fed to albino rats ...

Bacterial and Archaeal α-Amylases: Diversity and Amelioration of the Desirable Characteristics for Industrial Applications.

Science.gov (United States)

Mehta, Deepika; Satyanarayana, Tulasi

2016-01-01

Industrial enzyme market has been projected to reach US$ 6.2 billion by 2020. Major reasons for continuous rise in the global sales of microbial enzymes are because of increase in the demand for consumer goods and biofuels. Among major industrial enzymes that find applications in baking, alcohol, detergent, and textile industries are α-amylases. These are produced by a variety of microbes, which randomly cleave α-1,4-glycosidic linkages in starch leading to the formation of limit dextrins. α-Amylases from different microbial sources vary in their properties, thus, suit specific applications. This review focuses on the native and recombinant α-amylases from bacteria and archaea, their production and the advancements in the molecular biology, protein engineering and structural studies, which aid in ameliorating their properties to suit the targeted industrial applications.

Enzymatic Properties of an Alkaline and Chelator Resistant Proportional to alpha-Amylase from the Alkaliphilic Bacillus sp. Isolate L1711

Science.gov (United States)

Bernhardsdotter, Eva C. M. J.; Pusey, Marc L.; Ng, Joseph D.; Garriott, Owen K.

2004-01-01

An alkaliphilic amylase producing bacterium, Bacillus sp. strain L1711, was selected among 13 soda lakes isolates. When grown at pH 10.5 and 370 C, strain L1711 produced multiple forms of amylases in the culture broth. One of these, BAA, was purified from the culture supernatant by QAE column chromatography and preparative native gel electrophoresis. The molecular weight of BAA was determined to be 51 kDa by denaturing gel electrophoresis. The pH optima for activity below and above 40 C were 9.5-10.0 and 7.0-7.5 respectively. BAA was stable in the pH range 6-11 and was completely inactivated at 55?C. The thermostability was not increased in the presence of Ca(2+). The enzyme was strongly inhibited by Ca(2+), Zn(2+), Mg(2+), Mn(2+), Ba(2+) and Cu(2+), whereas the presence of Na(+), Co2+ and EDTA (10 mM) enhanced enzymatic activity. The K(sub m) and specific activity of BAA on soluble starch were 1.9 mg/ml and 18.5 U/mg respectively. The main end products of hydrolysis were maltotetraose, maltose and glucose .

Optimization of the growth conditions for amylase production by bacillus licheniformis 208 isolated from local hotsprings of karachi

International Nuclear Information System (INIS)

Asad, W.; Saleem, F.; Ajaz, M.; Rasool, S.A.

2014-01-01

Studies on the optimum conditions for the production of extracellular amylase were carried out with a newly isolated strain of Bacillus 208 from the hotsprings in Karachi. The optimum temperature, initial medium pH and incubation period for amylase production were 50 degree C, 7.0 and 24 hrs respectively. Furthermore, cells when grown in the complex media showed high amylase production compared to the minimal medium. Effect of different carbon sources revealed that soluble starch (1%) increased the amylase yield significantly. Peptone (as nitrogen source) gave higher yield as compared to other nitrogen sources tested. Under optimized conditions, the organism entered the stationary phase after 12 hrs and amylase production was observed to be maximum at 24th hrs of cultivation. Enzyme production regulation is influenced by catabolite repression. Reduction in enzyme production was observed in the presence of EDTA while addition of tween 20 and CaCl/sub 2/ helped to enhance the enzyme production. (author)

Production of Amylase by Bacillus polymyxa NCIM No. 2539 from Agroindustrial Wastes

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Abhishek Dutt Tripathi

2017-04-01

Full Text Available Background and Objective: In the present study, Bacillus polymyxa NCIM No. 2539 was selected to utilize agro-industrial byproduct (orange peel for amylase production under submergedfermentation conditions.Material and Methods: Different agro-industrial byproducts like cane molasses, wheat bran, rice bran and orange peel were screened for maximum amylase production. Amylase activitiy of Bacillus polymyxa was studied using starch-agar plate method. MINITAB software Version 17 and central composite design were applied to evaluate effect of supplementation of substrate with different sulphur containing amino acids (cysteine, methionine and cystine and vitamin thiamine on enzyme activity. Further optimization of the parameters viz. amount of substrate, concentration of amino acid and vitamin for maximum amylase production was studied by central composite rotatable design.Results and Conclusion: Among 4 different agro-industrial substrates applied, orange peel showed maximum enzyme production (activity: 492.31 IU g-1 sample. Supplementation of the production media with cysteine showed maximum amylaseproduction (515.38 IU g-1 sample among all three amino acids and control. Supplementation with thiamine also showed more amylase production (469.23 IU g-1 sample as compared to control (415.38 IU g-1. Cysteine and thiamine proved to increaseamylase production significantly. Maximum amylase production was obtained at 7.7 g orange peel, 37.29 mg cysteine and 34.23 mg per 10 ml thiamine.Conflict of interest: The authors declare no conflict of interest.

Preliminary insights into the impact of dietary starch on the ciliate, Neobalantidium coli, in captive chimpanzees.

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Kateřina Schovancová

Full Text Available Infections caused by the intestinal ciliate Neobalantidium coli are asymptomatic in most hosts. In humans and captive African great apes clinical infections occasionally occur, manifested mainly by dysentery; however, factors responsible for development of clinical balantidiasis have not been fully clarified. We studied the effect of dietary starch on the intensities of infection by N. coli in two groups of captive chimpanzees. Adult chimpanzees infected by N. coli from the Hodonín Zoo and from the Brno Zoo, Czech Republic, were fed with a high starch diet (HSD (average 14.7% of starch for 14 days, followed by a five-day transition period and subsequently with a period of low starch diet (LoSD (average 0.1% of starch for another 14 days. We collected fecal samples during the last seven days of HSD and LoSD and fixed them in 10% formalin. We quantified trophozoites of N. coli using the FLOTAC method. The numbers of N. coli trophozoites were higher during the HSD (mean ± SD: 49.0 ± 134.7 than during the LoSD (3.5 ± 6.8. A generalized linear mixed-effects model revealed significantly lower numbers of the N. coli trophozoites in the feces during the LoSD period in comparison to the HSD period (treatment contrast LoSD vs. HSD: 2.7 ± 0.06 (SE, z = 47.7; p<<0.001. We conclude that our data provide a first indication that starch-rich diet might be responsible for high intensities of infection of N. coli in captive individuals and might predispose them for clinically manifested balantidiasis. We discuss the potential nutritional modifications to host diets that can be implemented in part to control N. coli infections.

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.

Amylase activity of a starch degrading bacteria isolated from soil ...

African Journals Online (AJOL)

STORAGESEVER

2008-09-17

Sep 17, 2008 ... was maximum in the temperature range of 50 - 70oC, whereas this temperature range was deleterious for this ... The starch nutrient medium was inoculated with a single isolated .... (1983) high temperature may inactivate the.

Thermoplastic starch materials prepared from rice starch

International Nuclear Information System (INIS)

Pontes, Barbara R.B.; Curvelo, Antonio A.S.

2009-01-01

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)

Lack of effect of dietary fiber on serum lipids, glucose, and insulin in healthy young men fed high starch diets.

Science.gov (United States)

Ullrich, I H; Albrink, M J

1982-07-01

Eight healthy young men were fed a 72% carbohydrate high starch diet either high or low in dietary fiber for 4 days in a double cross-over design. Both groups showed a slight transient increase in plasma triglyceride level and a decrease in total and high-density lipoprotein cholesterol. There were few differences in glucose and insulin levels after glucose and meal tolerance tests after each diet. Fasting triglycerides and high-density lipoprotein cholesterol were inversely related at base-line; insulin response to oral glucose was inversely related to high-density lipoprotein cholesterol levels at the end of the study. We conclude that a high carbohydrate high starch diet, whether high or low in fiber, caused little increase in triglycerides, with little difference between the high and low fiber diets. Dietary fiber did not influence the fall in plasma cholesterol or high-density lipoprotein cholesterol concentrations over and above that seen after the low fiber diet.

Chemical Composition, Starch Digestibility and Antioxidant Capacity of Tortilla Made with a Blend of Quality Protein Maize and Black Bean

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Luis A. Bello-Pérez

2011-12-01

Full Text Available Tortilla and beans are the basic components in the diet of people in the urban and rural areas of Mexico. Quality protein maize is suggested for tortilla preparation because it presents an increase in lysine and tryptophan levels. Beans contain important amounts of dietary fiber. The objective of this study was to prepare tortilla with bean and assesses the chemical composition, starch digestibility and antioxidant capacity using a quality protein maize variety. Tortilla with bean had higher protein, ash, dietary fiber and resistant starch content, and lower digestible starch than control tortilla. The hydrolysis rate (60 to 50% and the predicted glycemic index (88 to 80 of tortilla decreased with the addition of bean in the blend. Extractable polyphenols and proanthocyanidins were higher in the tortilla with bean than control tortilla. This pattern produced higher antioxidant capacity of tortilla with bean (17.6 μmol Trolox eq/g than control tortilla (7.8 μmol Trolox eq/g. The addition of bean to tortilla modified the starch digestibility and antioxidant characteristics of tortilla, obtaining a product with nutraceutical characteristics.

Addition of Amylase from Aspergillus Awamori to the Diet of Broiler Chickens

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HS Morgado

Full Text Available ABSTRACT Two experiments were performed to evaluate the hematological and blood biochemistry parameters, biometry of digestive organs, enzyme activities, protein content and absolute weight of the pancreas of broilers fed pre-starter and pre-starter diets supplemented or not with amylase from Aspergillus awamori. In total, 120 male Cobb chicks were housed in heated cages in each experiment. A completely randomized experimental design, with two treatments (feed with and without amylase and six replicates per treatment of 10 birds each was applied. The data were subjected to analysis of variance using the F-test at 5% probability level. The dietary amylase addition did not affect hematological and blood biochemistry parameters and the biometry of the gastrointestinal tract of 7- and 21-d-old broilers, nor the absolute weight, enzyme activities or protein concentration of the pancreas of 7-d-old broilers. However, the inclusion of amylase in the diet reduced amylase activity and pancreatic protein concentration in 21-d-old broilers. The application of amylase to broiler chicken pre-starter and starter feeds is not justified given the pancreatic amylase activity and protein concentrations.

Beneficial effect of a high number of copies of salivary amylase AMY1 gene on obesity risk in Mexican children.

Science.gov (United States)

Mejía-Benítez, María A; Bonnefond, Amélie; Yengo, Loïc; Huyvaert, Marlène; Dechaume, Aurélie; Peralta-Romero, Jesús; Klünder-Klünder, Miguel; García Mena, Jaime; El-Sayed Moustafa, Julia S; Falchi, Mario; Cruz, Miguel; Froguel, Philippe

2015-02-01

Childhood obesity is a major public health problem in Mexico, affecting one in every three children. Genome-wide association studies identified genetic variants associated with childhood obesity, but a large missing heritability remains to be elucidated. We have recently shown a strong association between a highly polymorphic copy number variant encompassing the salivary amylase gene (AMY1 also known as AMY1A) and obesity in European and Asian adults. In the present study, we aimed to evaluate the association between AMY1 copy number and obesity in Mexican children. We evaluated the number of AMY1 copies in 597 Mexican children (293 obese children and 304 normal weight controls) through highly sensitive digital PCR. The effect of AMY1 copy number on obesity status was assessed using a logistic regression model adjusted for age and sex. We identified a marked effect of AMY1 copy number on reduced risk of obesity (OR per estimated copy 0.84, with the number of copies ranging from one to 16 in this population; p = 4.25 × 10(-6)). The global association between AMY1 copy number and reduced risk of obesity seemed to be mostly driven by the contribution of the highest AMY1 copy number. Strikingly, all children with >10 AMY1 copies were normal weight controls. Salivary amylase initiates the digestion of dietary starch, which is highly consumed in Mexico. Our current study suggests putative benefits of high number of AMY1 copies (and related production of salivary amylase) on energy metabolism in Mexican children.

Production of surfactant and detergent-stable, halophilic, and alkalitolerant alpha-amylase by a moderately halophilic Bacillus sp. Strain TSCVKK.

Science.gov (United States)

Kiran, Kondepudi Kanthi; Chandra, T S

2008-01-01

A moderately halophilic alkalitolerant Bacillus sp. Strain TSCVKK, with an ability to produce extracellular halophilic, alkalitolerant, surfactant, and detergent-stable alpha-amylase was isolated from soil samples obtained from a salt-manufacturing industry in Chennai. The culture conditions for higher amylase production were optimized with respect to NaCl, substrate, pH, and temperature. Maximum amylase production of 592 mU/ml was achieved in the medium at 48 h with 10% NaCl, 1% dextrin, 0.4% yeast extract, 0.2% tryptone, and 0.2% CaCl(2) at pH 8.0 at 30 degrees C. The enzyme activity in the culture supernatant was highest with 10% NaCl at pH 7.5 and 55 degrees C. The amylase that was partially purified by acetone precipitation was highly stable in various surfactants and detergents. Glucose, maltose, and maltooligosaccharides were the main end products of starch hydrolysis indicating that it is an alpha-amylase.

Bacterial and Archaeal α-amylases: Diversity and amelioration of the desirable characteristics for industrial applications

Directory of Open Access Journals (Sweden)

Deepika Mehta

2016-07-01

Full Text Available Industrial enzyme market has been projected to reach US$ 6.2 billion by 2020. Major reasons for continuous rise in the global sales of microbial enzymes are because of increase in the demand for consumer goods and biofuels. Among major industrial enzymes that find applications in baking, alcohol, detergent and textile industries are α-amylases. These are produced by a variety of microbes, which randomly cleave α-1,4-glycosidic linkages in starch leading to the formation of limit dextrins. α-Amylases from different microbial sources vary in their properties, thus, suit specific applications. This review focuses on the native and recombinant α-amylases from bacteria and archaea, their production and the advancements in the molecular biology, protein engineering and structural studies, which aid in ameliorating their properties to suit the targeted industrial applications.

Effect of banana pulp and peel flour on physicochemical properties and in vitro starch digestibility of yellow alkaline noodles.

Science.gov (United States)

Ramli, Saifullah; Alkarkhi, Abbas F M; Shin Yong, Yeoh; Min-Tze, Liong; Easa, Azhar Mat

2009-01-01

The present study describes the utilization of banana--Cavendish (Musa acuminata L., cv cavendshii) and Dream (Musa acuminata colla. AAA, cv 'Berangan')--pulp and peel flours as functional ingredients in yellow alkaline noodles. Noodles were prepared by partial substitution of wheat flour with ripe banana pulp or peel flours. In most cases, the starch hydrolysis index, predicted glycaemic index (pGI) and physicochemical properties of cooked noodles were affected by banana flour addition. In general, the pGI values of cooked noodles were in the order; banana peel noodles banana pulp noodles peel flour was higher in total dietary fibre but lower in resistant starch contents than the pulp flour, the low pGI of banana peel noodles was mainly due to its high dietary fibre content. In conclusion, banana pulp and peel flour could be useful for controlling starch hydrolysis of yellow noodles, even though some physicochemical properties of the noodles were altered.

Otimização das condições de cultivo para a produção de amilases pelo termofílico Bacillus sp. e hidrólise de amidos pela ação da enzima Optimization of culture conditions for the production of amylases by thermophilic Bacillus sp. and hydrolysis of starches by the action of the enzymes

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Raquel Vieira de Carvalho

2008-06-01

quantidades de açúcares redutores.The optimization of culture conditions for the production of α-amylase by the thermophilic Bacillus sp strain SMIA-2 was carried out. In addition, the enzymatic hydrolysis of starch from several sources, such as potato, cassava and corn was investigated. Alpha-amylase production by Bacillus sp SMIA-2 cultivated in liquid cultures containing starch as carbon source and supplemented with 0.5 g.L-1 whey protein and 2.0 g.L-1 peptone reached a maximum of 37 U.mL-1 at 32 hours. The microorganism was capable of utilizing several carbon sources, but amylase activity varied with each source. Starch was the best carbon source for amylase secretion, while lactose, maltose, sucrose, galactose, and glucose were not very effective. Decreasing starch concentration in the medium to 2.5 g.L-1 improved organism growth and enzyme activity. At higher starch concentrations, enzyme production was comparatively lower. Among the various organic and inorganic nitrogen sources, peptone (2.0 g.L-1 was found to be the best. Regarding the amount of whey protein in the medium, the concentration of 0.25 g.L-1 was considered the most effective for amylase secretion by the organism. Maximum amylase activity was observed at 50 °C and pH 8.5. The enzyme was able to degrade all the starches tested. Potato starch hydrolysis resulted in a higher yield of reducing sugars in comparison to the other starches. Soluble and cassava starch were, respectively, in second and third positions regarding the liberation of reducing sugars, while the amylase studied showed a slightly lower affinity for corn starch. Increasing the reaction temperature to 70 °C resulted in higher levels of reducing sugars after the hydrolysis of the substrates, except for soluble starch.

Functional characterization and crystal structure of thermostable amylase from Thermotoga petrophila, reveals high thermostability and an unusual form of dimerization

DEFF Research Database (Denmark)

Hameed, Uzma; Price, Ian; Ikram-Ul-Haq

2017-01-01

and able to hydrolyze starch into dextrin between 90 and 100°C, with optimum activity at 98°C and pH8.5. The activity increased in the presence of Rb(1+), K(1+) and Ca(2+) ions, whereas other ions inhibited activity. The crystal structure of Tp-AmyS at 1.7Å resolution showed common features of the GH-13...... of salivary amylase from a previous crystal structure, and thus could be a functional feature of some amylases....

The role of Aspergillus flavus veA in the production of extracellular proteins during growth on starch substrates.

Science.gov (United States)

Duran, Rocio M; Gregersen, Scott; Smith, Timothy D; Bhetariya, Preetida J; Cary, Jeffrey W; Harris-Coward, Pamela Y; Mattison, Christopher P; Grimm, Casey; Calvo, Ana M

2014-06-01

The aflatoxin-producer and opportunistic plant pathogenic, filamentous fungus Aspergillus flavus is responsible for the contamination of corn and other important agricultural commodities. In order to obtain nutrients from the host A. flavus produces a variety of extracellular hydrolytic enzymes. Interestingly, A. flavus amylase and protease activity are dependent on the global regulator veA, a gene known to regulate morphogenesis and secondary metabolism in numerous fungi. Analysis of starch degradation by fungal enzymes secreted into broths of starch- or corn kernel-based media showed a notable accumulation of glucose in samples of the A. flavus control strain while the deletion veA sample accumulated high levels of maltose and maltotriose and only a small amount of glucose. Furthermore, SDS-PAGE and proteomics analysis of culture broths from starch- or corn kernel-based media demonstrated differential production of a number of proteins that included a reduction in the amount of a glucoamylase protein in the veA mutant compared to the control strain, while an alpha-amylase was produced in greater quantities in the veA mutant. Quantitative real-time PCR and western blot analyses using anti-glucoamylase or alpha-amylase antisera supported the proteomics results. Additionally, an overall reduction in protease activity was observed in the veA mutant including production of the alkaline protease, oryzin, compared to the control strain. These findings contribute to our knowledge of mechanisms controlling production of hydrolases and other extracellular proteins during growth of A. flavus on natural starch-based substrates.

Effect of dietary starch concentration and fish oil supplementation on milk yield and composition, diet digestibility, and methane emissions in lactating dairy cows.

Science.gov (United States)

Pirondini, M; Colombini, S; Mele, M; Malagutti, L; Rapetti, L; Galassi, G; Crovetto, G M

2015-01-01

The aim of this study was to evaluate the effects of diets with different starch concentrations and fish oil (FO) supplementation on lactation performance, in vivo total-tract nutrient digestibility, N balance, and methane (CH4) emissions in lactating dairy cows. The experiment was conducted as a 4×4 Latin square design with a 2×2 factorial arrangement: 2 concentrations of dietary starch [low vs. high: 23.7 and 27.7% on a dry matter (DM) basis; neutral detergent fiber/starch ratios: 1.47 and 1.12], the presence or absence of FO supplement (0.80% on a DM basis), and their interaction were evaluated. Four Italian Friesian cows were fed 1 of the following 4 diets in 4 consecutive 26-d periods: (1) low starch (LS), (2) low starch plus FO (LSO), (3) high starch (HS), and (4) high starch plus FO (HSO). The diets contained the same amount of forages (corn silage, alfalfa and meadow hays). The starch concentration was balanced using different proportions of corn meal and soybean hulls. The cows were housed in metabolic stalls inside open-circuit respiration chambers to allow measurement of CH4 emission and the collection of separate urine and feces. No differences among treatments were observed for DM intake. We observed a trend for FO to increase milk yield: 29.2 and 27.5kg/d, on average, for diets with and without FO, respectively. Milk fat was affected by the interaction between dietary starch and FO: milk fat decreased only in the HSO diet. Energy-corrected milk (ECM) was affected by the interaction between starch and FO, with a positive effect of FO on the LS diet. Fish oil supplementation decreased the n-6:n-3 ratio of milk polyunsaturated fatty acids. High-starch diets negatively influenced all digestibility parameters measured except starch, whereas FO improved neutral detergent fiber digestibility (41.9 vs. 46.1% for diets without and with FO, respectively, and ether extract digestibility (53.7 vs. 67.1% for diets without and with FO, respectively). We observed

The influence of α-amylase supplementation, γ-irradiation (60Co) as well as long time of storage of wheat grain on flour technological properties

International Nuclear Information System (INIS)

Warchalewski, J.R.

1989-01-01

The varieties of winter wheat, Aria and Beta, were studied. The Aria variety was stored for the period of four years. The part of wheat grain from Beta variety was irradiated with γ rays ( 60 Co). In extracts from wheat kernels and flour protein content, total α- and β-amylolytic activity as well as α-amylolytic activity were determined, α-amylases of native and fungal origin were added to the flour obtained from samples of stored wheat kernels (Aria), irradiated and non-irradiated (Beta). Consequently native α-amylase activity of flour increased by 25% and 50%, respectively. Extensive technological estimation of grain and flour with amylase supplements was carried out. The study included: sedimentation analysis, falling number test, milling experiment, farinogram and extensogram analyses, measurement of the degree of damaged starch and flour colour, as well as baking experiment. The obtained experimental loaves of bread were tested for their ability to remain fresh. It was found out that the stored grain flour was characterized by the highest α-amylolytic activity and the lowest falling number value, whereas the irradiated grain flour showed the highest degree of starch damage and water absorption. When α-amylase supplementation to doughs was not accompanied by either irradiation or storage of grain, it definitely changed their physical properties for the worse. The negative influence of native α-amylases appeared to be less significant than that of fungal α-amylases. The positive influence of α-amylase supplementations, especially of those increasing by 25% the native α-amylolytic activity of flour on volume, and freshness of loaves of bread was observed. (author)

Resistant Starch Contents of Native and Heat-Moisture Treated Jackfruit Seed Starch

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Ornanong S. Kittipongpatana

2015-01-01

Full Text Available Native jackfruit seed starch (JFS contains 30% w/w type II resistant starch (RS2 and can potentially be developed as a new commercial source of RS for food and pharmaceutical application. Heat-moisture treatment (HMT was explored as a mean to increase RS content of native JFS. The effect of the conditions was tested at varied moisture contents (MC, temperatures, and times. Moisture levels of 20–25%, together with temperatures 80–110°C, generally resulted in increases of RS amount. The highest amount of RS (52.2% was achieved under treatment conditions of 25% MC and 80°C, for 16 h (JF-25-80-16. FT-IR peak ratio at 1047/1022 cm−1 suggested increases in ordered structure in several HMT-JFS samples with increased RS. SEM showed no significant change in the granule appearance, except at high moisture/temperature treatment. XRD revealed no significant change in peaks intensities, suggesting the crystallinity within the granule was mostly retained. DSC showed increases in Tg and, in most cases, ΔT, as the MC was increased in the samples. Slight but significant decreases in ΔH were observed in samples with low RS, indicating that a combination of high moisture and temperature might cause partial gelatinization. HMT-JFS with higher RS exhibited less swelling, while the solubility remained mostly unchanged.

Amylase activity of a starch degrading bacteria isolated from soil ...

African Journals Online (AJOL)

Starch degrading bacteria are most important for industries such as food, fermentation, textile and paper. Thus isolating and manipulating pure culture from various waste materials has manifold importance for various biotechnology industries. In the present investigation a bacterial strain was isolated from soil sample ...

The effect of baking and enzymatic treatment on the structural properties of wheat starch.

Science.gov (United States)

Fuentes, Catalina; Zielke, Claudia; Prakash, Manish; Kumar, Puneeth; Peñarrieta, J Mauricio; Eliasson, Ann-Charlotte; Nilsson, Lars

2016-12-15

In this study, bread was baked with and without the addition of α-amylase. Starch was extracted from the baked bread and its molecular properties were characterized using (1)H NMR and asymmetric flow field-flow fractionation (AF4) connected to multi-angle light scattering (MALS) and other detectors. The approach allows determination of molar mass, root- mean-square radius and apparent density as well as the average degree of branching of amylopectin. The results show that starch size and structure is affected as a result of the baking process. The effect is larger when α-amylase is added. The changes include both a decrease molar mass and size as well as an increase in apparent density. Moreover, an increase in average degree of branching and the number of reducing ends H-1(β-r) and H-1(α-r) can be observed. Copyright © 2016. Published by Elsevier Ltd.

Studies on gamma-irradiation of high amylose corn starch, 1

International Nuclear Information System (INIS)

Watanabe, Yukio; Ayano, Yuko; Obara, Tetsujiro.

1976-01-01

Amylomaize 7, amylomaize 5, normal corn, waxy corn and potato starches were irradiated with 60 Co-gamma rays at the dose levels from 2x10 4 to 100x10 4 rad to determine the changes in physicochemical properties by irradiation. Irradiated starches were characterized by determination of amylography, specific viscosity, blue value, pH, acidity, carbonyl content, reducing value and limit of β-amylolysis. Irradiated starches showed a decrease in viscosity and blue value, and an increase in reducing value with increasing dose levels. These results were seemed to indicate the degradation of starch molecule. A slight oxidation of starch was suggested by a decrease in pH and an increase in acidity and carbonyl content. Amylomaize 7 and amylomaize 5 starches were less sensitive than the other starches in terms of irradiation effects. The rheological properties determined by amylography and Ostwald viscometer changed at the lowest dose (5x10 4 rad) and the other properties changed above 20x10 4 rad. The limits of β-amylase hydrolysis of normal corn, waxy corn and potato starches increased slightly by irradiation (100x10 4 rad). On the other hand, β-amylolysis limits of amylomaize 7 and amylomaize 5 starches were lower about 5.5% and 2.5% respectively than that of nonirradiated samples. The decrease of β-amylolysis limit enlarged with increasing amylose content. (auth.)

Production and Catalytic Properties of Amylases from Lichtheimia ramosa and Thermoascus aurantiacus by Solid-State Fermentation

Science.gov (United States)

de Oliveira, Ana Paula Aguero; Silvestre, Maria Alice; Garcia, Nayara Fernanda Lisboa; Alves-Prado, Heloíza Ferreira; Rodrigues, André; da Paz, Marcelo Fossa; Fonseca, Gustavo Graciano

2016-01-01

The present study compared the production and the catalytic properties of amylolytic enzymes obtained from the fungi Lichtheimia ramosa (mesophilic) and Thermoascus aurantiacus (thermophilic). The highest amylase production in both fungi was observed in wheat bran supplemented with nutrient solution (pH 4.0) after 96 hours of cultivation, reaching 417.2 U/g of dry substrate (or 41.72 U/mL) and 144.5 U/g of dry substrate (or 14.45 U/mL) for L. ramosa and T. aurantiacus, respectively. The enzymes showed higher catalytic activity at pH 6.0 at 60°C. The amylases produced by L. ramosa and T. aurantiacus were stable between pH 3.5–10.5 and pH 4.5–9.5, respectively. The amylase of L. ramosa was stable at 55°C after 1 hour of incubation, whereas that of T. aurantiacus maintained 60% of its original activity under the same conditions. Both enzymes were active in the presence of ethanol. The enzymes hydrolyzed starch from different sources, with the best results obtained with corn starch. The enzymatic complex produced by L. ramosa showed dextrinizing and saccharifying potential. The enzymatic extract produced by the fungus T. aurantiacus presented only saccharifying potential, releasing glucose monomers as the main hydrolysis product. PMID:27413773

Production and Catalytic Properties of Amylases from Lichtheimia ramosa and Thermoascus aurantiacus by Solid-State Fermentation

Directory of Open Access Journals (Sweden)

Ana Paula Aguero de Oliveira

2016-01-01

Full Text Available The present study compared the production and the catalytic properties of amylolytic enzymes obtained from the fungi Lichtheimia ramosa (mesophilic and Thermoascus aurantiacus (thermophilic. The highest amylase production in both fungi was observed in wheat bran supplemented with nutrient solution (pH 4.0 after 96 hours of cultivation, reaching 417.2 U/g of dry substrate (or 41.72 U/mL and 144.5 U/g of dry substrate (or 14.45 U/mL for L. ramosa and T. aurantiacus, respectively. The enzymes showed higher catalytic activity at pH 6.0 at 60°C. The amylases produced by L. ramosa and T. aurantiacus were stable between pH 3.5–10.5 and pH 4.5–9.5, respectively. The amylase of L. ramosa was stable at 55°C after 1 hour of incubation, whereas that of T. aurantiacus maintained 60% of its original activity under the same conditions. Both enzymes were active in the presence of ethanol. The enzymes hydrolyzed starch from different sources, with the best results obtained with corn starch. The enzymatic complex produced by L. ramosa showed dextrinizing and saccharifying potential. The enzymatic extract produced by the fungus T. aurantiacus presented only saccharifying potential, releasing glucose monomers as the main hydrolysis product.

Immobilization of α-Amylase from Anoxybacillus sp. SK3-4 on ReliZyme and Immobead Supports

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Ummirul Mukminin Kahar

2016-09-01

Full Text Available α-Amylase from Anoxybacillus sp. SK3-4 (ASKA is a thermostable enzyme that produces a high level of maltose from starches. A truncated ASKA (TASKA variant with improved expression and purification efficiency was characterized in an earlier study. In this work, TASKA was purified and immobilized through covalent attachment on three epoxide (ReliZyme EP403/M, Immobead IB-150P, and Immobead IB-150A and an amino-epoxide (ReliZyme HFA403/M activated supports. Several parameters affecting immobilization were analyzed, including the pH, temperature, and quantity (mg of enzyme added per gram of support. The influence of the carrier surface properties, pore sizes, and lengths of spacer arms (functional groups on biocatalyst performances were studied. Free and immobilized TASKAs were stable at pH 6.0–9.0 and active at pH 8.0. The enzyme showed optimal activity and considerable stability at 60 °C. Immobilized TASKA retained 50% of its initial activity after 5–12 cycles of reuse. Upon degradation of starches and amylose, only immobilized TASKA on ReliZyme HFA403/M has comparable hydrolytic ability with the free enzyme. To the best of our knowledge, this is the first report of an immobilization study of an α-amylase from Anoxybacillus spp. and the first report of α-amylase immobilization using ReliZyme and Immobeads as supports.

Resistant starch and arabinoxylan augment SCFA absorption, but affect postprandial glucose and insulin responses differently - CORRIGENDUM

DEFF Research Database (Denmark)

Ingerslev, Anne Krog; Theil, Peter Kappel; Hedemann, Mette Skou

2015-01-01

The effects of increased colonic fermentation of dietary fibres (DF) on net portal flux (NPF) of carbohydrate-derived metabolites (glucose, SCFA and especially butyrate), hormones (insulin, C-peptide, GLP-1, GIP) and NEFA were studied in a healthy catheterised pig model. Six 59 ± 3.8 kg pigs were...... fitted with catheters in the mesenteric artery, the portal and hepatic vein, and a flowprobe around the portal vein and included in a double 3x3 crossover design with three daily feedings (at 9.00, 14.00 and 19.00 hours). Fasting and 5 hours postprandial blood samples were collected after 7 days...... adaptation to each diet. The pigs were fed a low DF western style control diet (WSD) and two high DF diets; an arabinoxylan (AXD) and a resistant starch (RSD) enriched diet. The NPF of insulin was lower (P = 0.04) in AXD fed pigs (4.6 nmol/h) compared to RSD fed pigs (10.5 nmol/h), despite the lowest NPF...

Comparison of Morphology and Physicochemical Properties of Starch Among 3 Arrowhead Varieties.

Science.gov (United States)

Li, Aimin; Zhang, Yunhong; Zhang, Yongji; Yu, Xurun; Xiong, Fei; Zhou, Rumei; Zhang, Yongtai

2016-05-01

Arrowhead (Sagittaria trifolia var. sinensis) is a source of starch worldwide, but arrowhead starch has been rarely studied. In this work, starch was separated from arrowhead corm. The morphology and physicochemical properties of starch were then investigated and compared among 3 different arrowhead varieties (Purple-corm, Hongta, and Japanese). Results showed that starches from the 3 varieties similarly featured an oval shape containing a visible polarization cross, a CA -type crystalline structure, and an ordered structure in the external granule region. However, starch content, granule size, crystal characteristics, and pasting properties differed among the 3 varieties. Japanese arrowhead exhibited the highest starch content and degree of ordered structure in the external granule region, as well as onset, peak, and final gelatinization temperature. Purple-corm arrowhead starch demonstrated the highest amylose content and relative degree of crystallinity, smallest granule size, and lowest swelling power and solubility. Purple-corm arrowhead starch also showed the highest gelatinization enthalpy, as well as peak, trough, final, and setback viscosities. This starch further presented the lowest breakdown viscosity and degree of hydrolysis by HCl and porcine pancreatic α-amylase. These findings can provide useful references for arrowhead variety selection in food and nonfood industries. © 2016 Institute of Food Technologists®

Effect of gamma radiation on physico-chemical characteristics of red gram (Cajanus cajan) starch

International Nuclear Information System (INIS)

Nene, S.P.; Vakil, U.K.; Sreenivasan, A.

1975-01-01

Total reducing and nonreducing sugars in red gram (Cajanus cajan) are not affected by radiation treatment (1 Mrad). Oligosaccharides, reported as flatulence factors in legumes, namely stachyose and raffinose, are slightly decreased on cooking the irradiated samples. Irradiated and cooked red gram starch is more susceptible to alpha-amylase action than the unirradiated sample. Rheological properties of red gram starch, such as gelatinization viscosity, swelling power and solubility improve on irradiation resulting in a final cooked product with better textural properties. (U.S.)

Atividade da amilase no intestino delgado de coelhos alimentados com dietas contendo diferentes níveis de amido antes e após desmame = Amylase activity in the small intestine of rabbits fed with diets containing starch levels before and after weaning

Directory of Open Access Journals (Sweden)

Haroldo Garcia de Faria

2006-07-01

Full Text Available Para avaliar a atividade amilásica em coelhos após a desmama, foram utilizados 200 animais da Raça Nova Zelândia Branco, submetidos a diferentes padrões de alimentação desde a fase de lactação. Quarenta deles foram abatidos aos 35 dias de idade e 80, aos 50 e aos 70 dias de idade. Para modular o padrão de consumo de leite e ração antes da desmama, as ninhadas equalizadas em 8 láparos do nascimento até ao 16º dia de idade, a partir desta idade, até a desmama, foram submetidos à alta e baixa disponibilidade de leite, mantendo ninhadas com 4 ou 8 láparos recebendo dietas com nível normal (15% e alto (24% de amido. A partir da desmama, os animais de cada um dos 4 padrões de alimentação até a desmama passaram a receber as mesmasdietas com níveis normal e alto de amido, em um esquema fatorial 2x2x2 (ninhadas submetidas à baixa e alta disponibilidade de leite versus dois níveis de amido na dieta até a desmama versus doisníveis de amido na dieta após a desmama. Os resultados mostraram que a manutenção de ninhadas com 4 ou 8 animais entre o 16º e 35º dia de lactação não modificou (P>0,05 a atividade da amilase em qualquer das idades avaliadas após o desmame. O uso de dietas com alto teor de amido durante a lactação aumentou (POne experiment was carried out to study the amylase activity in the small intestine (jejunum and ileum of rabbits from litters maintained on different feeding patterns. Two hundred White New Zealand rabbits were analyzed, out of which 40 35- days-old rabbits, 80 50-days-old rabbits and 80 70-days-old rabbits were slaughtered. To modulate the pattern of feed and milk intake before weaning, the litters were modulated for eight young rabbits until 16 days old. From 16 days until weaning, they were submitted to low or high milkavailability, litters maintained with four or eight young rabbits receiving diets containing normal or high starch level. The animals were distributed in a factorial design 2

Starch Digestibility and Functional Properties of Rice Starch Subjected to Gamma Radiation

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Luís Fernando Polesi

2018-01-01

Full Text Available This study investigated the effect of gamma radiation on the digestibility and functional properties of rice starch. Rice cultivars IRGA417 and IAC202 were used for isolation of starch by the alkaline method. Starch samples were irradiated with 1, 2 and 5 kGy doses of 60Co at a rate of 0.4 kGy/h. A control sample, which was not irradiated, was used for comparison. Irradiated and control starches were characterized by in vitro starch digestibility, total dietary fiber, color, water absorption index, water solubility index, syneresis, swelling factor, amylose leaching, pasting properties and gel firmness. Irradiations changed starch digestibility differently in either cultivar. Increasing radiation doses promoted increase in the color parameter b* (yellow, elevation in the capacity to absorb water, and solubility in water as well as the amylose leached from granules for both cultivars. Pasting properties showed a decrease that was proportional to the dose applied, caused by the depolymerization of starch molecules. Gel firmness of the starch from IAC202 was inversely proportional to the radiation dose applied, whereas for IRGA417, there was a reduction at 5 kGy dose. Rice starches can be modified by irradiation to exhibit different functional characteristics and they can be used by the food industries in products such as soups, desserts, flans, puddings and others.

Isolation and characterisation of nanoparticles from tef and maize starch modified with stearic acid

CSIR Research Space (South Africa)

Cuthbert, WO

2017-07-01

Full Text Available Nanoparticles were isolated from tef and maize starch modified with added stearic acid after pasting at 90 °C for 130 min. This was followed by thermo-stable alpha-amylase hydrolysis of the paste. The resultant residues were then characterized using...

Optimization of the production of extracellular α-amylase by Kluyveromyces marxianus IF0 0288 by response surface methodology

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Panagiota-Yiolanda Stergiou

2014-06-01

Full Text Available The aim of this work was to study the production of extracellular α-amylase by Kluyveromyces marxianus IF0 0288 using optimized nutritional and cultural conditions in a complex yeast medium under aerobic batch fermentation. By applying the conventional "one-variable-at-a-time" approach and the response surface methodology, the effect of four fermentation parameters (type of carbon source, initial culture pH, temperature, and incubation time on the growth and α-amylase production was evaluated. The production of α-amylase during 60 h of fermentation increased 13-fold under optimized conditions (1% starch, pH 6.0, 30ºC in comparison to the conventional optimization method. The initial pH value of 6.13 and temperature of 30.3ºC were optimal conditions by the response surface methodology, leading to further improvement (up to 13-fold in the production of extracellular α-amylase. These results constituted first evidence that K. marxianus could be potentially used as an effective source of extracellular α-amylase.

Effect of the medium composition on formation of amylase by Bacillus sp

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Eliana de Oliveira. Santos

2003-01-01

Full Text Available Studies on the alpha -amylase synthesis was carried out with a moderately thermophilic, facultatively anaerobic Bacillus sp, isolated from soil samples. The cells were cultivated in a complex medium containing soluble starch or maltose as carbon source. The levels of the alpha -amylaseactivity detected in culture supernatants varied greatly with the type of carbon source used. Maltose, soluble starch and citrate stimulated alpha -amylaseformation. Addition of exogenous glucose repressed formation of alpha -amylase, demonstrating that a classical glucose effect was operative in this organism. The concentration of yeast extract was found to be important factor in the alpha -amylase synthesis bythe isolate.The activity of the enzyme increased between 2 and 5 g/L yeast extract concentration and then fell very rapidly beyond this point. The best concentration of peptone to alpha-amylase formation was found to be around 10g/L.Estudos sobre a síntese de alfa -amilase foram realizados com uma bactéria termofílica moderada e facultativa anaeróbica, isolada de amostras de solo. As células foram cultivadas em um meio complexo contendo amido solúvel ou maltose como fonte de carbono. Os níveis da atividade de alfa -amilase detectados no sobrenadante da cultura variaram grandemente com o tipo da fonte de carbono utilizada. Amido solúvel, maltose e citrato estimularam a formação de alfa -amilase. A adição de glicose as culturas reprimiu a formação da alfa -amilase, demonstrando que o clássico efeito glicose foi operativo neste organismo. A concentração de extrato de levedura foi um fator importante na formação de alfa -amilase pelo isolado. A atividade da enzima aumentou entre concentrações de 2 a 5 g/L e então caiu muito rapidamente em torno deste ponto. A melhor concentração de peptona para a formação da alfa -amilase foi em torno de 10 g/L.

Type-4 Resistant Starch in Substitution for Available Carbohydrate Reduces Postprandial Glycemic Response and Hunger in Acute, Randomized, Double-Blind, Controlled Study

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Maria L. Stewart

2018-01-01

Full Text Available Resistant starch (RS is a type of dietary fiber that has been acknowledged for multiple physiological benefits. Resistant starch type 4 (RS4 is a subcategory of RS that has been more intensively studied as new types of RS4 emerge in the food supply. The primary aim of this randomized, double-blind, controlled study was to characterize the postprandial glucose response in healthy adults after consuming a high fiber scone containing a novel RS4 or a low fiber control scone without RS4. Secondary aims included assessment of postprandial insulin response, postprandial satiety, and gastrointestinal tolerance. The fiber scone significantly reduced postprandial glucose and insulin incremental areas under the curves (43–45% reduction, 35–40% reduction, respectively and postprandial glucose and insulin maximum concentrations (8–10% and 22% reduction, respectively. The fiber scone significantly reduced hunger and desire to eat during the 180 min following consumption and yielded no gastrointestinal side effects compared with the control scone. The results from this study demonstrate that a ready-to-eat baked-good, such as a scone, can be formulated with RS4 replacing refined wheat flour to yield statistically significant and clinically meaningful reductions in blood glucose and insulin excursions. This is the first study to report increased satiety after short-term RS4 intake, which warrants further investigation in long-term feeding studies.

Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus

Science.gov (United States)

Martos-Sitcha, Juan Antonio; Perdomo-Morales, Rolando; Casuso, Antonio; Montero-Alejo, Vivian; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

2016-01-01

Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase. PMID:27391425

Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus.

Directory of Open Access Journals (Sweden)

Leandro Rodríguez-Viera

Full Text Available Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase.

Molecular, Biochemical, and Dietary Regulation Features of α-Amylase in a Carnivorous Crustacean, the Spiny Lobster Panulirus argus.

Science.gov (United States)

Rodríguez-Viera, Leandro; Perera, Erick; Martos-Sitcha, Juan Antonio; Perdomo-Morales, Rolando; Casuso, Antonio; Montero-Alejo, Vivian; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan Miguel

2016-01-01

Alpha-amylases are ubiquitously distributed throughout microbials, plants and animals. It is widely accepted that omnivorous crustaceans have higher α-amylase activity and number of isoforms than carnivorous, but contradictory results have been obtained in some species, and carnivorous crustaceans have been less studied. In addition, the physiological meaning of α-amylase polymorphism in crustaceans is not well understood. In this work we studied α-amylase in a carnivorous lobster at the gene, transcript, and protein levels. It was showed that α-amylase isoenzyme composition (i.e., phenotype) in lobster determines carbohydrate digestion efficiency. Most frequent α-amylase phenotype has the lowest digestion efficiency, suggesting this is a favoured trait. We revealed that gene and intron loss have occurred in lobster α-amylase, thus lobsters express a single 1830 bp cDNA encoding a highly conserved protein with 513 amino acids. This protein gives rise to two isoenzymes in some individuals by glycosylation but not by limited proteolysis. Only the glycosylated isoenzyme could be purified by chromatography, with biochemical features similar to other animal amylases. High carbohydrate content in diet down-regulates α-amylase gene expression in lobster. However, high α-amylase activity occurs in lobster gastric juice irrespective of diet and was proposed to function as an early sensor of the carbohydrate content of diet to regulate further gene expression. We concluded that gene/isoenzyme simplicity, post-translational modifications and low Km, coupled with a tight regulation of gene expression, have arose during evolution of α-amylase in the carnivorous lobster to control excessive carbohydrate digestion in the presence of an active α-amylase.

Barley grain constituents, starch composition, and structure affect starch in vitro enzymatic hydrolysis.

Science.gov (United States)

Asare, Eric K; Jaiswal, Sarita; Maley, Jason; Båga, Monica; Sammynaiken, Ramaswami; Rossnagel, Brian G; Chibbar, Ravindra N

2011-05-11

The relationship between starch physical properties and enzymatic hydrolysis was determined using ten different hulless barley genotypes with variable carbohydrate composition. The ten barley genotypes included one normal starch (CDC McGwire), three increased amylose starches (SH99250, SH99073, and SB94893), and six waxy starches (CDC Alamo, CDC Fibar, CDC Candle, Waxy Betzes, CDC Rattan, and SB94912). Total starch concentration positively influenced thousand grain weight (TGW) (r(2) = 0.70, p starch concentration (r(2) = -0.80, p hydrolysis of pure starch (r(2) = -0.67, p starch concentration (r(2) = 0.46, p starch (RS) in meal and pure starch samples. The rate of starch hydrolysis was high in pure starch samples as compared to meal samples. Enzymatic hydrolysis rate both in meal and pure starch samples followed the order waxy > normal > increased amylose. Rapidly digestible starch (RDS) increased with a decrease in amylose concentration. Atomic force microscopy (AFM) analysis revealed a higher polydispersity index of amylose in CDC McGwire and increased amylose genotypes which could contribute to their reduced enzymatic hydrolysis, compared to waxy starch genotypes. Increased β-glucan and dietary fiber concentration also reduced the enzymatic hydrolysis of meal samples. An average linkage cluster analysis dendrogram revealed that variation in amylose concentration significantly (p starch concentration in meal and pure starch samples. RS is also associated with B-type granules (5-15 μm) and the amylopectin F-III (19-36 DP) fraction. In conclusion, the results suggest that barley genotype SH99250 with less decrease in grain weight in comparison to that of other increased amylose genotypes (SH99073 and SH94893) could be a promising genotype to develop cultivars with increased amylose grain starch without compromising grain weight and yield.

Effects of calcium ion concentration on starch hydrolysis of barley α-amylase isozymes

DEFF Research Database (Denmark)

Yuk, Jeong-Bin; Choi, Seung-Ho; Lee, Tae-Hee

2008-01-01

Barley (x-amylase genes, amyl and amy2, were separately cloned into the expression vector of pPICZ alpha A and recombinant Pichia strains were established by homologous recombination. Both AMYs from Pichia shared almost identical hydrolysis patterns on short maltooligosaccharides to result...

Effect of dietary starch source and concentration on equine fecal microbiota

Science.gov (United States)

Starch from corn is less susceptible to equine small intestinal digestion than starch from oats, and starch that reaches the hindgut can be utilized by the microbiota. The objective of the current study was to examine the effects of starch source on equine fecal microbiota. Thirty horses were assig...

Purification and some properties of a novel maltohexaose-producing exo-amylase from Aerobacter aerogenes.

Science.gov (United States)

Kainuma, K; Wako, K; Kobayashi, S; Nogami, A; Suzuki, S

1975-12-18

Maltohexaose producing amylase (EC 3.2.1.-) is the fourth known exo-amylase, the three previously known being glucoamylase, beta-amylase and Pseudomonas stutzeri maltotetraose producing amylase. The enzyme after release from Aerobacter aerogenes cells by 0.1% sodium lauryl sulfate extraction was purified by ammonium sulfate precipitation, DEAE-Sephadex column chromatography and Sephadex G-100 gel filtration to 80-fold of the original sodium lauryl sulfate extract activity, It gave a single band on disc electrophoresis, and the molecular weight by gel filtration was 54 000. This amylase showed maximal activity at 50 degrees C and pH 6.80. The pH stability range was relatively wide, the enzyme retaining more than 90% of its initial activity in the range of 6.50-9.0. 80% of the activity was retained after 15 min at 50 degrees C. This enzyme produced maltohexaose from starch, amylose and amylopectin by exo-attack, but did not act on alpha- or beta-cyclodextrin, pullulan or maltohexaitol. Also the enzyme acted on beta-limit dextrins of amylopectin and glycogen to form branched oligosaccharides. The unusual reaction of this enzyme on beta-limit dextrin is discussed from the standpoint of the stereochemistry of 1,4-alpha- and 1,6-alpha-glucosidic bonds. This is the anomalous amylase for which it is recognized that 1,6-alpha-glucosidic linkages in the substrates can mimic the effect of 1,4-alpha-bonds, as previously observed in pseudo-priming reactions of E. coli phosphorylase.

alfa-Amylase as a reliable and convenient measure of sympathetic activity: don’t start salivating just yet!

NARCIS (Netherlands)

Bosch, JA; Veerman, J.W.; de Geus, E.J.C.; Proctor, J.

2011-01-01

Recent years have seen a growing interest in salivary α-amylase (sAA) as a non-invasive marker for sympathetic nervous system (SNS) activity. Saliva offers many advantages as a biomarker fluid and sAA is one of its most plentiful components. sAA is a digestive enzyme that breaks down starch, which

α-Amylase as a reliable and convenient measure of sympathetic activity: don't start salivating just yet!

NARCIS (Netherlands)

Bosch, J.A.; Veerman, E.C.I.; de Geus, E.J.; Proctor, G.B.

2011-01-01

Recent years have seen a growing interest in salivary α-amylase (sAA) as a non-invasive marker for sympathetic nervous system (SNS) activity. Saliva offers many advantages as a biomarker fluid and sAA is one of its most plentiful components. sAA is a digestive enzyme that breaks down starch, which

Starch and oil in the donor cow diet and starch in substrate differently affect the in vitro ruminal biohydrogenation of linoleic and linolenic acids.

Science.gov (United States)

Zened, A; Troegeler-Meynadier, A; Nicot, M C; Combes, S; Cauquil, L; Farizon, Y; Enjalbert, F

2011-11-01

Trans isomers of fatty acids exhibit different health properties. Among them, trans-10,cis-12 conjugated linoleic acid has negative effects on milk fat production and can affect human health. A shift from the trans-11 to the trans-10 pathway of biohydrogenation (BH) can occur in the rumen of dairy cows receiving high-concentrate diets, especially when the diet is supplemented with highly unsaturated fat sources. The differences of BH patterns between linoleic acid (LeA) and linolenic acid (LnA) in such ruminal conditions remain unknown; thus, the aim of this work was to investigate in vitro the effects of starch and sunflower oil in the diet of the donor cows and starch level in the incubates on the BH patterns and efficiencies of LeA and LnA. The design was a 4 × 4 Latin square design with 4 cows, 4 periods, and 4 diets with combinations of 21 or 34% starch and 0 or 5% sunflower oil. The rumen content of each cow during each period was incubated with 4 substrates, combining 2 starch levels and either LeA or LnA addition. Capillary electrophoresis single-strand conformation polymorphism of incubates showed that dietary starch decreased the diversity of the bacterial community and the high-starch plus oil diet modified its structure. High-starch diets poorly affected isomerization and first reduction of LeA and LnA, but decreased the efficiencies of trans-11,cis-15-C18:2 and trans C18:1 reduction. Dietary sunflower oil increased the efficiency of LeA isomerization but decreased the efficiency of trans C18:1 reduction. An interaction between dietary starch and dietary oil resulted in the highest trans-10 isomers production in incubates when the donor cow received the high-starch plus oil diet. The partition between trans-10 and trans-11 isomers was also affected by an interaction between starch level and the fatty acid added to the incubates, showing that the trans-10 shift only occurred with LeA, whereas LnA was mainly hydrogenated via the more usual trans-11

Dietary fibre as functional ingredient in meat products: a novel approach for healthy living - a review.

Science.gov (United States)

Verma, Arun Kumar; Banerjee, Rituparna

2010-06-01

There is a rapid change in our overall lifestyle due to impact of globalization. Every day hasty life has forced consumers to be dependent upon fast foods, which contain meagre amount of dietary fibre. Non-starch polysaccharides and resistant oligosaccharides, lignin, substances associated with NSP and lignin complex in plants, other analogous carbohydrates, such as resistant starch and dextrins, and synthesized carbohydrate compounds, like polydextrose are categorized as dietary fibre. They are mostly concentrated in cereals, pulses, fruits and vegetables. It has been proclaimed that daily dietary fibre intake helps in prevention of many nutritional disorders like gut related problems, cardiovascular diseases, type 2 diabetes, certain types of cancer and obesity. Meat is generally lacking this potential ingredient, which could be incorporated while products processing to make them more healthful. Various fibre rich sources have been attempted in different products attributed to their technological and health benefits and many are in the queue to be used in a variety of meat products. Selection of appropriate fibre rich ingredients and their proper incorporation can improve health image of meat products.

Glycemic Response to Corn Starch Modified with Cyclodextrin Glycosyltransferase and its Relationship to Physical Properties.

Science.gov (United States)

Dura, A; Yokoyama, W; Rosell, C M

2016-09-01

Corn starch was modified with cyclodextrin glycosyltransferase (CGTase) below the gelatinization temperature. The porous granules with or without CGTase hydrolysis products may be used as an alternative to modified corn starches in foods applications. The amount and type of hydrolysis products were determined, containing mainly β-cyclodextrin (CD), which will influence pasting behavior and glycemic response in mice. Irregular surface and small holes were observed by microscopic analysis and differences in pasting properties were observed in the presence of hydrolysis products. Postprandial blood glucose in mice fed gelatinized enzymatically modified starch peaked earlier than their ungelatinized counterparts. However, in ungelatinized enzymatically modified starches, the presence of β- CD may inhibit the orientation of amylases slowing hydrolysis, which may help to maintain lower blood glucose levels. Significant correlations were found between glycemic curves and viscosity pattern of starches.

Detection of antibiotic resistance in probiotics of dietary supplements

KAUST Repository

Wong, Aloysius Tze

2015-09-14

Background Probiotics are live microorganisms that confer nutrition- and health-promoting benefits if consumed in adequate amounts. Concomitant with the demand for natural approaches to maintaining health is an increase in inclusion of probiotics in food and health products. Since probiotic bacteria act as reservoir for antibiotic resistant determinants, the transfer of these genes to pathogens sharing the same intestinal habitat is thus conceivable considering the fact that dietary supplements contain high amounts of often heterogeneous populations of probiotics. Such events can confer pathogens protection against commonly-used drugs. Despite numerous reports of antibiotic resistant probiotics in food and biological sources, the antibiogram of probiotics from dietary supplements remained elusive. Findings Here, we screened five commercially available dietary supplements for resistance towards antibiotics of different classes. Probiotics of all batches of products were resistant towards vancomycin while batch-dependent resistance towards streptomycin, aztreonam, gentamycin and/or ciprofloxacin antibiotics was detected for probiotics of brands Bi and Bn, Bg, and L. Isolates of brand Cn was also resistant towards gentamycin, streptomycin and ciprofloxacin antibiotics. Additionally, we also report a discrepancy between the enumerated viable bacteria amounts and the claims of the manufacturers. Conclusions This short report has highlighted the present of antibiotic resistance in probiotic bacteria from dietary supplements and therefore serves as a platform for further screenings and for in-depth characterization of the resistant determinants and the molecular machinery that confers the resistance.

The Effect of Trans-Chalcone on Amylase Activity, Blood Glucose and Lipid Levels in Diabetic and Non Diabetic Rats

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M Najafian

2011-04-01

Full Text Available Introduction & Objective: Alpha amylase is the most important decomposing enzyme in starch. Digestion and absorption of starch in the intestine can be prevented and also the blood sugar levels can be controlled by restrain and control of alpha amylase. The aim of this study was to evaluate the effect of trans-chalcone on amylase activity, blood glucose and lipid levels in diabetic and non diabetic rats. Materials & Methods: This experimental study was conducted in 1388 at Tehran University of Medical Sciences. Sixty rats were randomly divided to ten equal groups: non diabetic control, diabetic control, four non diabetic experiments and four diabetic experiments. Control groups received grape seed oil and experimental groups received 2, 8,16 and 32 mg/kg of body weight in a period of 24 days with a gastric cannula. Blood sugar, every two days, serum insulin levels in days 0,12, and 24 and at the end of the experiment, lipoproteins and alpha amylase activity were measured.The data were analyzed by one way analysis of variance, ANOVA, followed by Turkey,s test with SPSS soft ware . Results: On average Chalcone reduced 25.5% of blood sugar in normal and diabetic rats. IT also decreased the serum insulin level. On average, chalcone decreased 34.9% of alpha amylase activity in normal and diabetic rats. Following disturbances in lipids metabolism caused by diabetes, this drug improved lipoproteins metabolism and reduced water, food and urine volume. Conclusion: This study shows that trans-Chalcone reduces blood sugar and body weight via inhibition of alpha amylas. Moreover, improvement of lipoprotein metabolism may happen via the inhibitory effect of this drug on hydroxyl methyl glutaryl -COA reductase and phosphodiesterase.

Nutritional perfomance of Tupinambis merianae lizards fed with corn starch as source of energy

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Harold Vega Parry

2009-07-01

Full Text Available Efficiency in processing complex carbohydrates as a source of energy was studied in Tupinambis merianae lizards. Four isoproteic and isoenergetic diets in which different percentages of corn starch substituted fat (0, 10, 20 and 30 dry matter in the diet were provided. Even though consumption was similar in all diets, growth and feeding conversion rates decreased significantly with corn starch supplies of 10% and more. At the end of the trial, pancreatic alpha-amylase activity showed correlated increases, yet these were insufficient to compensate corn starch supplies. Results suggest that Tupinambis merianae lizards have a restricted omnivorous capacity. Therefore, diet formulation for these lizards should exclude high molecular weight carbohydrates.

Composition, properties and health benefits of indigestible carbohydrate polymers as dietary fiber: a review.

Science.gov (United States)

Mudgil, Deepak; Barak, Sheweta

2013-10-01

In last few decades, indigestible carbohydrates as dietary fiber have attracted interest of food scientists and technologists due to its several physiological benefits. Dietary fibers are generally of two types based on their solubility, i.e. soluble and insoluble dietary fiber. Significant physicochemical properties of dietary fiber include solubility, viscosity, water holding capacity, bulking and fermentability. Some important dietary fibers are celluloses, hemicelluloses, hydrocolloids, resistant starches and non-digestible oligosaccharides. Inclusion of these fibers in daily diet imparts several health benefits such as prevention or reduction of bowel disorders, and decrease risk of coronary heart disease and type 2 diabetes. Copyright © 2013 Elsevier B.V. All rights reserved.

ENZYMATIC DETERMINATION OF STARCH IN DOCE DE LEITE USING DIALYSIS

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DEMIATE Ivo Motim

2001-01-01

Full Text Available The importance of starch for the food industry makes it necessary to develop new, fast, economic and accurate methodologies for its quantification. In the present paper starch hydrolysis using commercial enzymes of industrial grade are studied aiming to develop an easy and cheap analysis, available to a greater number of industries and technicians. The proposed method is simple, divided in a first step where soluble sugars are eliminated from the samples by using dialysis, followed by starch hydrolysis of the retained fraction with a thermoresistent bacterial alfa-amylase (Termamyl 120L® and an amyloglucosidase (AMG 300L®. The hydrolysis conditions were those suggested by the enzyme producer. After the hydrolysis step the material was dialysed again for the extraction of glucose that was quantified by the glucose-oxidase colorimetric reactant. The results allowed the construction of calibration equations for starch determination on the analyzed samples. These samples were produced on a laboratory scale and native and acid-modified corn starches were added in known concentrations. By considering the final dilutions employed for glucose determination on the samples, it was possible to confirm that they were identical to that of the glucose-oxidase reactant calibration.

Transcriptome wide identification and characterization of starch branching enzyme in finger millet.

Science.gov (United States)

Tyagi, Rajhans; Tiwari, Apoorv; Garg, Vijay Kumar; Gupta, Sanjay

2017-01-01

Starch-branching enzymes (SBEs) are one of the four major enzyme classes involved in starch biosynthesis in plants and play an important role in determining the structure and physical properties of starch granules. Multiple SBEs are involved in starch biosynthesis in plants. Finger millet is calcium rich important serial crop belongs to grass family and the transcriptome data of developing spikes is available on NCBI. In this study it was try to find out the gene sequence of starch branching enzyme and annotate the sequence and submit the sequence for further use. Rice SBE sequence was taken as reference and for characterization of the sequence different in silico tools were used. Four domains were found in the finger millet Starch branching enzyme like alpha amylase catalytic domain from 925 to2172 with E value 0, N-terminal Early set domain from 634 to 915 with E value 1.62 e-42, Alpha amylase, C-terminal all-beta domain from 2224 to 2511 with E value 5.80e-24 and 1,4-alpha-glucan-branching enzyme from 421 to 2517 with E value 0. Major binding interactions with the GLC (alpha-d-glucose), CA (calcium ion), GOL (glycerol), TRS (2-amino-2-hydroxymethylpropane- 1, 3-diol), MG (magnesium ion) and FLC (citrate anion) are fond with different residues. It was found in the phylogenetic study of the finger millet SBE with the 6 species of grass family that two clusters were form A and B. In cluster A, finger millet showed closeness with Oryzasativa and Setariaitalica, Sorghum bicolour and Zea mays while cluster B was formed with Triticumaestivum and Brachypodium distachyon. The nucleotide sequence of Finger millet SBE was submitted to NCBI with the accession no KY648913 and protein structure of SBE of finger millet was also submitted in PMDB with the PMDB id - PM0080938. This research presents a comparative overview of Finger millet SBE and includes their properties, structural and functional characteristics, and recent developments on their post-translational regulation.

Codon Optimization Significantly Improves the Expression Level of α-Amylase Gene from Bacillus licheniformis in Pichia pastoris

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Jian-Rong Wang

2015-01-01

Full Text Available α-Amylase as an important industrial enzyme has been widely used in starch processing, detergent, and paper industries. To improve expression efficiency of recombinant α-amylase from Bacillus licheniformis (B. licheniformis, the α-amylase gene from B. licheniformis was optimized according to the codon usage of Pichia pastoris (P. pastoris and expressed in P. pastoris. Totally, the codons encoding 305 amino acids were optimized in which a total of 328 nucleotides were changed and the G+C content was increased from 47.6 to 49.2%. The recombinants were cultured in 96-deep-well microplates and screened by a new plate assay method. Compared with the wild-type gene, the optimized gene is expressed at a significantly higher level in P. pastoris after methanol induction for 168 h in 5- and 50-L bioreactor with the maximum activity of 8100 and 11000 U/mL, which was 2.31- and 2.62-fold higher than that by wild-type gene. The improved expression level makes the enzyme a good candidate for α-amylase production in industrial use.

Recurrent Rearrangements of Human Amylase Genes Create Multiple Independent CNV Series.

Science.gov (United States)

Shwan, Nzar A A; Louzada, Sandra; Yang, Fengtang; Armour, John A L

2017-05-01

The human amylase gene cluster includes the human salivary (AMY1) and pancreatic amylase genes (AMY2A and AMY2B), and is a highly variable and dynamic region of the genome. Copy number variation (CNV) of AMY1 has been implicated in human dietary adaptation, and in population association with obesity, but neither of these findings has been independently replicated. Despite these functional implications, the structural genomic basis of CNV has only been defined in detail very recently. In this work, we use high-resolution analysis of copy number, and analysis of segregation in trios, to define new, independent allelic series of amylase CNVs in sub-Saharan Africans, including a series of higher-order expansions of a unit consisting of one copy each of AMY1, AMY2A, and AMY2B. We use fiber-FISH (fluorescence in situ hybridization) to define unexpected complexity in the accompanying rearrangements. These findings demonstrate recurrent involvement of the amylase gene region in genomic instability, involving at least five independent rearrangements of the pancreatic amylase genes (AMY2A and AMY2B). Structural features shared by fundamentally distinct lineages strongly suggest that the common ancestral state for the human amylase cluster contained more than one, and probably three, copies of AMY1. © 2017 WILEY PERIODICALS, INC.

Starch digestion in the small intestine of broiler chickens differs among feedstuffs

NARCIS (Netherlands)

Weurding, R.E.; Veldman, A.; Veen, W.A.G.; Aar, van de P.J.; Verstegen, M.W.A.

2001-01-01

Dietary starch is the major energy source for broiler chickens, and knowledge about its digestive behavior can be important. In a digestibility trial with 720 broiler chickens, site, rate and extent of starch digestion were measured for 12 feedstuffs. Starch digestion was determined using the

Sweetening syrup production by enzymatic hydrolysis of starch variety yam (Dioscorea rotundata

Directory of Open Access Journals (Sweden)

Carlos Ramón Vidal Tovar

2011-04-01

Full Text Available Sweeteners syrups produced by enzymatic hydrolysis from starch of hawthorn yam (Dioscorea rotundata. The starch was extracted by a scratched, washed, sedimented and drying; the yield was quantified taking into account the amount of initial raw material and was determined the concentration of starch, amylose, amylopectin, crude fiber, ash, protein, fat and humidity in accordance with the requirements of the AOAC standards, and ICONTEC COVENIN. Enzymatic hydrolysis of starch was conducted using ∂-amylase, glucoamylase and pullulanase in starch solutions at 36 and 46 % w/w varying the order of application of glucoamylase and pullulanase were determined pH, Brix, moisture, reducing sugars (AR, total sugar (TS and the dextrose equivalent (ED in the syrups obtained. In the liquefaction were obtained with an intermediate syrups sweeteners ED 18.81% and 22.15%. Syrups low and medium conversion with an ED between 34-45% in the first saccharification and high conversion syrups with a DE between 75-79% as a final product. The above values allow the use of hawthorn yam starch syrup production for multiple uses in different food industry processes.

Preparation and Characterization of Some Polyethylene Modified- Starch Biodegradable Films

International Nuclear Information System (INIS)

Badrana, A.S.; Ramadanb, A.M.; Ibrahim, N.A.; Kahild, T.; Hussienc, H.A.

2005-01-01

Blends of LDPE with soluble starch, wheat flour and commercial starch were prepared by mixing starch (or flour) with styrene then blending the mixture with LDPE, The starch percents vary between 5 and 50% of the total weight. Their physical and mechanical properties were recorded and compared with pure LDPE. It was observed that the increase in starch or wheat flour contents of the mixture was reversibly proportional to the tensile strength and % elongation. Samples were tested for water absorption. All of the samples were insoluble in cold and boiling water. Moisture uptake increased with immersion time and increasing starch content. The changes in the tensile strength of LDPE/starch (or wheat flour) after the course of thermal oxidation was measured. These results show negligible changes in the tensile strength of the control sample as compared to that of the samples containing the additives. Oxidation processes take advantage of the high temperatures (40-50 degree C) and the time. It was also observed that after 10 weeks of soil burial, the mechanical properties of the films decrease, mainly, due to starch removal from the films. Also, for the weight loss a drastic decrease was observed after 10 weeks of soil burial thereafter it preceded slowly. The LDPE/ starch strips showed weight loss after treating with a-amylase this due to hydrolysis and leaching of the starch. The rate of starch hydrolysis increases with the increase in starch content of the sample. The influence of addition of starch on the overall migration of these films, with different food simulant, was studied, at different temperatures (-4 degree. 25 degree and 40 degree C). All values were significantly lower than the upper limit for overall migration set by the EU (10 mg/dirf) for food grade plastics packaging materials

In vitro batch fecal fermentation comparison of gas and short-chain fatty acid production using "slowly fermentable" dietary fibers.

Science.gov (United States)

Kaur, Amandeep; Rose, Devin J; Rumpagaporn, Pinthip; Patterson, John A; Hamaker, Bruce R

2011-01-01

Sustained colonic fermentation supplies beneficial fermentative by-products to the distal colon, which is particularly prone to intestinal ailments. Blunted/delayed initial fermentation may also lead to less bloating. Previously, we reported that starch-entrapped alginate-based microspheres act as a slowly fermenting dietary fiber. This material was used in the present study to provide a benchmark to compare to other "slowly fermentable" fibers. Dietary fibers with previous reports of slow fermentation, namely, long-chain inulin, psyllium, alkali-soluble corn bran arabinoxylan, and long-chain β-glucan, as well as starch-entrapped microspheres were subjected to in vitro upper gastrointestinal digestion and human fecal fermentation and measured over 48 h for pH, gas, and short-chain fatty acids (SCFA). The resistant fraction of cooked and cooled potato starch was used as another form of fermentable starch and fructooligosaccharides (FOS) served as a fast fermenting control. Corn bran arabinoxylan and long-chain β-glucan initially appeared slower fermenting with comparatively low gas and SCFA production, but later fermented rapidly with little remaining in the final half of the fermentation period. Long-chain inulin and psyllium had slow and moderate, but incomplete, fermentation. The resistant fraction of cooked and cooled potato starch fermented rapidly and appeared similar to FOS. In conclusion, compared to the benchmark slowly fermentable starch-entrapped microspheres, a number of the purported slowly fermentable fibers fermented fairly rapidly overall and, of this group, only the starch-entrapped microspheres appreciably fermented in the second half of the fermentation period. Consumption of dietary fibers, particularly commercial prebiotics, leads to uncomfortable feelings of bloating and flatulence due to their rapid degradation in our large intestine. This article employs claimed potential slowly fermenting fibers and compares their fermentation rates

Intestinal transport and fermentation of resistant starch evaluated by the hydrogen breath test

DEFF Research Database (Denmark)

Olesen, M; Rumessen, J J; Gudmand-Høyer, E

1994-01-01

To study fermentability of different samples of resistant starch (RS), compared to one another and to lactulose, and to study the effect on gastric emptying of addition of RS to test meal. Finally to study if adaptation to RS results in a measurable change in fermentation pattern, (H2/CH4...

Synthesis, spectroscopic characterization of palladium(II)-orthohydroxyacetophenone azine nano-optical sensor doped in sol–gel matrix and its use as probe for assessment of α-amylase activity in human saliva

International Nuclear Information System (INIS)

El-Sayed, B.A.; Abo-Aly, M.M.; Attia, M.S.; Gamal, S.

2016-01-01

PdAPA (palladium(II)-orthohydroxyacetophenone azine) complex doped in sol–gel matrix is synthesized. It is characterized using UV-visible, infrared spectra and TEM image. A novel, simple, sensitive spectrofluorometric method was developed for measuring the activity of the α-amylase enzyme in human saliva for smokers and non-smokers with age range (17–64 years) based on the quenching of the luminescence intensity at 450 nm of the new synthesized complex characterized by various concentrations of the maltose released from the hydrolysis of starch by α-amylase enzyme and was successfully used as nano-optical sensor. The calibration plot was achieved over the concentration range 4.7×10 −6 –9.3×10 −10 mol L −1 maltose with a correlation coefficient of 0.996 and a detection minimum limit value of 7.55×10 −10 mol L −1 . The method was satisfactorily used for the assessment of the α-amylase activity in a number of human saliva samples for various smokers and non-smoker's volunteers. - Highlights: • The (palladium(II)-orthohydroxyacetophenone azine) complex doped in sol–gel was prepared. • It was used for the assessment of of α-amylase enzyme activity. • By maltose resulting from the reaction of α-amylase enzyme with starch. • A novel, simple, sensitive and precise spectrofluorometric method was developed.

Hydration properties and phosphorous speciation in native, gelatinized and enzymatically modified potato starch analyzed by solid-state MAS NMR

DEFF Research Database (Denmark)

Larsen, Flemming H.; Kasprzak, Miroslaw Marek; Lærke, Helle Nygaard

2013-01-01

Hydration of granular, gelatinized and molecularly modified states of potato starch in terms of molecular mobility were analyzed by 13C and 31P solid-state MAS NMR. Gelatinization (GEL) tremendously reduced the immobile fraction compared to native (NA) starch granules. This effect was enhanced...... by enzyme-assisted catalytic branching with branching enzyme (BE) or combined BE and β-amylase (BB) catalyzed exo-hydrolysis. Carbons of the glycosidic α-1,6 linkages required high hydration rates before adopting uniform chemical shifts indicating solid-state disorder and poor water accessibility...... regions was only observed in NA starch. Moreover phosphorous was observed in a minor pH-insensitive form and as major phosphate in hydrated GEL and BE starches....

Dietary sugar/starches intake and Barrett's esophagus: a pooled analysis.

Science.gov (United States)

Li, Nan; Petrick, Jessica Leigh; Steck, Susan Elizabeth; Bradshaw, Patrick Terrence; McClain, Kathleen Michele; Niehoff, Nicole Michelle; Engel, Lawrence Stuart; Shaheen, Nicholas James; Corley, Douglas Allen; Vaughan, Thomas Leonard; Gammon, Marilie Denise

2017-11-01

Barrett's esophagus (BE) is the key precursor lesion of esophageal adenocarcinoma, a lethal cancer that has increased rapidly in westernized countries over the past four decades. Dietary sugar intake has also been increasing over time, and may be associated with these tumors by promoting hyperinsulinemia. The study goal was to examine multiple measures of sugar/starches intake in association with BE. This pooled analysis included 472 BE cases and 492 controls from two similarly conducted case-control studies in the United States. Dietary intake data, collected by study-specific food frequency questionnaires, were harmonized across studies by linking with the University of Minnesota Nutrient Database, and pooled based on study-specific quartiles. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for age, sex, race, total energy intake, study indicator, body mass index, frequency of gastro-esophageal reflux, and fruit/vegetable intake. In both studies, intake of sucrose (cases vs. controls, g/day: 36.07 vs. 33.51; 36.80 vs. 35.06, respectively) and added sugar (46.15 vs. 41.01; 44.18 vs. 40.68, respectively) were higher in cases than controls. BE risk was increased 79% and 71%, respectively, for associations comparing the fourth to the first quartile of intake of sucrose (OR Q4vs.Q1  = 1.79, 95% CI = 1.07-3.02, P trend  = 0.01) and added sugar (OR Q4vs.Q1  = 1.71, 95% CI = 1.05-2.80, P trend  = 0.15). Intake of sweetened desserts/beverages was associated with 71% increase in BE risk (OR Q4vs.Q1  = 1.71, 95% CI = 1.07-2.73, P trend  = 0.04). Limiting dietary intake of foods and beverages that are high in added sugar, especially refined table sugar, may reduce the risk of developing BE.

Kinetic modeling and exploratory numerical simulation of chloroplastic starch degradation

Directory of Open Access Journals (Sweden)

Nag Ambarish

2011-06-01

Full Text Available Abstract Background Higher plants and algae are able to fix atmospheric carbon dioxide through photosynthesis and store this fixed carbon in large quantities as starch, which can be hydrolyzed into sugars serving as feedstock for fermentation to biofuels and precursors. Rational engineering of carbon flow in plant cells requires a greater understanding of how starch breakdown fluxes respond to variations in enzyme concentrations, kinetic parameters, and metabolite concentrations. We have therefore developed and simulated a detailed kinetic ordinary differential equation model of the degradation pathways for starch synthesized in plants and green algae, which to our knowledge is the most complete such model reported to date. Results Simulation with 9 internal metabolites and 8 external metabolites, the concentrations of the latter fixed at reasonable biochemical values, leads to a single reference solution showing β-amylase activity to be the rate-limiting step in carbon flow from starch degradation. Additionally, the response coefficients for stromal glucose to the glucose transporter kcat and KM are substantial, whereas those for cytosolic glucose are not, consistent with a kinetic bottleneck due to transport. Response coefficient norms show stromal maltopentaose and cytosolic glucosylated arabinogalactan to be the most and least globally sensitive metabolites, respectively, and β-amylase kcat and KM for starch to be the kinetic parameters with the largest aggregate effect on metabolite concentrations as a whole. The latter kinetic parameters, together with those for glucose transport, have the greatest effect on stromal glucose, which is a precursor for biofuel synthetic pathways. Exploration of the steady-state solution space with respect to concentrations of 6 external metabolites and 8 dynamic metabolite concentrations show that stromal metabolism is strongly coupled to starch levels, and that transport between compartments serves to

The impact of extrusion on the nutritional composition, dietary fiber and in vitro digestibility of gluten-free snacks based on rice, pea and carob flour blends.

Science.gov (United States)

Arribas, C; Cabellos, B; Sánchez, C; Cuadrado, C; Guillamón, E; Pedrosa, M M

2017-10-18

Consumers and the food industry are demanding healthier products. Expanded snacks with a high nutritional value were developed from different rice, pea and carob flour blends. The proximate composition, starch (total and resistant), amylose and amylopectin, dietary fiber (soluble and insoluble) contents, and the in vitro protein digestibility of different rice-legume formulations, were evaluated before and after the extrusion process. Compared with the corresponding non-extruded blends (control), the extrusion treatment did not change the total protein content, however, it reduced the soluble protein (61-86%), the fat (69-92%) and the resistant starch contents (100%). The total starch content of all studied blends increased (2-19%) after extrusion. The processing increased the in vitro protein digestibility, reaching values around 88-95% after extrusion. Total dietary fiber was reduced around 30%, and the insoluble fraction was affected to a larger extent than the soluble fraction by the extrusion process. Because of its balanced nutritional composition, high dietary fiber content, as well as low energy density, these novel gluten-free snack-like foods could be considered as functional foods and a healthier alternative to commercially available gluten-containing or gluten-free and low nutritional value snacks.

Improved α-amylase production by Aspergillus oryzae after a double deletion of genes involved in carbon catabolite repression.

Science.gov (United States)

Ichinose, Sakurako; Tanaka, Mizuki; Shintani, Takahiro; Gomi, Katsuya

2014-01-01

In filamentous fungi, the expression of secretory glycoside hydrolase encoding genes, such as those for amylases, cellulases, and xylanases, is generally repressed in the presence of glucose. CreA and CreB have been observed to be regulating factors for carbon catabolite repression. In this study, we generated single and double deletion creA and/or creB mutants in Aspergillus oryzae. The α-amylase activities of each strain were compared under various culture conditions. For the wild-type strain, mRNA levels of α-amylase were markedly decreased in the later stage of submerged culture under inducing conditions, whereas this reduced expression was not observed for single creA and double creA/creB deletion mutants. In addition, α-amylase activity of the wild-type strain was reduced in submerged culture containing high concentrations of inducing sugars, whereas all constructed mutants showed higher α-amylase activities. In particular, the α-amylase activity of the double deletion mutant in a medium containing 5% starch was >10-fold higher than that of the wild-type strain under the same culture conditions. In solid-state cultures using wheat bran as a substrate, the α-amylase activities of single creA and double deletion mutants were >2-fold higher than that of the wild-type strain. These results suggested that deleting both creA and creB resulted in dramatic improvements in the production of secretory glycoside hydrolases in filamentous fungi.

Biochemical studies of amylase, lipase and protease in Callosobruchus maculatus (Coleoptera: Chrysomelidae) populations fed with Vigna unguiculata grain cultivated with diazotrophic bacteria strains.

Science.gov (United States)

Silva, L B; Torres, É B; Nóbrega, R A S; Lopes, G N; Vogado, R F; Pavan, B E; Fernandes-Junior, P I

2017-12-01

The objective of this study was to evaluate the enzymatic activity of homogenates of insects fed on grain of cowpea, Vigna unguiculata (L.), cultivars grown with different nitrogen sources. For the experiment we used aliquots of the homogenate of 100 unsexed adult insects, emerged from 10 g of grain obtained from four cowpea cultivars: 'BRS Acauã', 'BRS Carijó', 'BRS Pujante', and 'BRS Tapaihum' grown under different regimes of nitrogen sources: mineral fertilizer, inoculation with strains of diazotrophs (BR 3267, BR 3262, BR 3299; INPA 03-11B, 03-84 UFLA, as well as the control (with soil nitrogen). The parameters evaluated were enzymatic activities of insect protease, amylase and lipase and the starch content of the grains. There were differences in the enzymatic activity of amylase, lipase and protease of insect homogenate according to the food source. A lower activity of the enzyme amylase from C. maculatus homogenate was observed when insects were fed grain of the cultivar BRS Carijó. A lower activity of lipase enzyme from C. maculatus homogenate was observed when the insects fed on grain from the interaction of the cultivar Tapaihum inoculated with BR 3262 diazotrophs. The lowest proteolytic activity was observed in homogenate of insects fed on interaction of 'BRS Carijó' inoculated with BR 3262 diazotrophs. Starch content correlated positively with the amylase activity of C. maculatus homogenate. The cultivar BRS Carijó had a different behavior from the other cultivars, according to the cluster analysis.

Estimated environmental loads of alpha-amylase from transgenic high-amylase maize

Energy Technology Data Exchange (ETDEWEB)

Wolt, Jeffrey D. [Department of Agronomy, Iowa State University, Ames, IA 50011 (United States); Biosafety Institute for Genetically Modified Agricultural Products, 164 Seed Science, Iowa State University, Ames, IA 50011 (United States); Karaman, Sule [Biosafety Institute for Genetically Modified Agricultural Products, 164 Seed Science, Iowa State University, Ames, IA 50011 (United States)

2007-11-15

Environmental exposure of plants bioengineered to improve efficiencies of biofuel production is an important consideration for their adoption. High-amylase maize genetically engineered to produce thermostable alpha-amylase in seed endosperm is currently in development, and its successful adoption will entail >1000 km{sup 2} of annual production in the USA. Environmental exposure of thermostable amylase will occur in production fields from preharvest and harvest dropped grain, with minor additional contributions from stover and root biomass. Mass loadings of thermostable alpha-amylase are projected to be 16 kg km{sup -2} and represent a potential source of increased alpha-amylase activity in receiving soils. An understanding of the degradation, persistence, accumulation, and activity of thermostable alpha-amylase introduced from transgenic high-amylase maize will be necessary in order to effectively manage transgenic crop systems intended or biofeedstock production. (author)

Dietary components in the development of leptin resistance.

Science.gov (United States)

Vasselli, Joseph R; Scarpace, Philip J; Harris, Ruth B S; Banks, William A

2013-03-01

Classically, leptin resistance has been associated with increased body fat and circulating leptin levels, and the condition is believed to contribute to the onset and/or maintenance of obesity. Although a great deal is known about the central nervous system mechanisms mediating leptin resistance, considerably less is known about the role of diet in establishing and maintaining this altered hormonal state. An exciting new finding has recently been published demonstrating the existence of leptin resistance in normal-weight rats with lean leptin levels by feeding them a high-concentration-fructose diet. This finding has opened the possibility that specific macronutrients may be capable of inducing leptin resistance, independently of the amount of body fat or circulating leptin present in the treated animals. This review describes several lines of research that have recently emerged indicating that specific types of dietary sugars and fats are capable of inducing leptin resistance in experimental rodent models. The results further show that diet-induced leptin resistance is capable of increasing energy intake and elevating body weight gain under appropriate dietary challenges. It appears that biological mechanisms on multiple levels may underlie the dietary induction of leptin resistance, including alterations in the leptin blood-to-brain transport system, in peripheral glucose metabolism, and in central leptin receptor signaling pathways. What is clear from the findings reviewed here is that diet-induced leptin resistance can occur in the absence of elevated circulating leptin levels and body weight, rendering it a potential cause and/or predisposing factor to excess body weight gain and obesity.

Determination of total dietary fiber (CODEX definition) by enzymatic-gravimetric method and liquid chromatography: collaborative study.

Science.gov (United States)

McCleary, Barry V; DeVries, Jonathan W; Rader, Jeanne I; Cohen, Gerald; Prosky, Leon; Mugford, David C; Champ, Martine; Okuma, Kazuhiro

2010-01-01

A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official Methods 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37 degrees C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 11.57 to 47.83%. Digestion of samples under the conditions of AOAC Method 2002.02 followed by the isolation and gravimetric procedures of AOAC Methods 985.29 and 991.43 results in quantitation of HMWDF. The filtrate from the quantitation of HMWDF is concentrated, deionized, concentrated again, and analyzed by LC to determine the LMWSDF, i.e., all nondigestible oligosaccharides of degree of polymerization > or =3. TDF is calculated as the sum of HMWDF and LMWSDF. Repeatability standard deviations (Sr) ranged from 0.41 to 1.43, and reproducibility standard deviations (S(R)) ranged from 1.18 to 5.44. These results are comparable to other official dietary fiber methods, and the method is recommended for adoption as Official First Action.

In vitro digestibility of banana starch cookies.

Science.gov (United States)

Bello-Pérez, Luis A; Sáyago-Ayerdi, Sonia G; Méndez-Montealvo, Guadalupe; Tovar, Juscelino

2004-01-01

Banana starch was isolated and used for preparation of two types of cookies. Chemical composition and digestibility tests were carried out on banana starch and the food products, and these results were compared with corn starch. Ash, protein, and fat levels in banana starch were higher than in corn starch. The high ash amount in banana starch could be due to the potassium content present in this fruit. Proximal analysis was similar between products prepared with banana starch and those based on corn starch. The available starch content of the banana starch preparation was 60% (dmb). The cookies had lower available starch than the starches while banana starch had lower susceptibility to the in vitro alpha-amylolysis reaction. Banana starch and its products had higher resistant starch levels than those made with corn starch.

Improved Starch Digestion of Sucrase-deficient Shrews Treated With Oral Glucoamylase Enzyme Supplements.

Science.gov (United States)

Nichols, Buford L; Avery, Stephen E; Quezada-Calvillo, Roberto; Kilani, Shadi B; Lin, Amy Hui-Mei; Burrin, Douglas G; Hodges, Benjamin E; Chacko, Shaji K; Opekun, Antone R; Hindawy, Marwa El; Hamaker, Bruce R; Oda, Sen-Ichi

2017-08-01

Although named because of its sucrose hydrolytic activity, this mucosal enzyme plays a leading role in starch digestion because of its maltase and glucoamylase activities. Sucrase-deficient mutant shrews, Suncus murinus, were used as a model to investigate starch digestion in patients with congenital sucrase-isomaltase deficiency.Starch digestion is much more complex than sucrose digestion. Six enzyme activities, 2 α-amylases (Amy), and 4 mucosal α-glucosidases (maltases), including maltase-glucoamylase (Mgam) and sucrase-isomaltase (Si) subunit activities, are needed to digest starch to absorbable free glucose. Amy breaks down insoluble starch to soluble dextrins; mucosal Mgam and Si can either directly digest starch to glucose or convert the post-α-amylolytic dextrins to glucose. Starch digestion is reduced because of sucrase deficiency and oral glucoamylase enzyme supplement can correct the starch maldigestion. The aim of the present study was to measure glucogenesis in suc/suc shrews after feeding of starch and improvement of glucogenesis by oral glucoamylase supplements. Sucrase mutant (suc/suc) and heterozygous (+/suc) shrews were fed with C-enriched starch diets. Glucogenesis derived from starch was measured as blood C-glucose enrichment and oral recombinant C-terminal Mgam glucoamylase (M20) was supplemented to improve starch digestion. After feedings, suc/suc and +/suc shrews had different starch digestions as shown by blood glucose enrichment and the suc/suc had lower total glucose concentrations. Oral supplements of glucoamylase increased suc/suc total blood glucose and quantitative starch digestion to glucose. Sucrase deficiency, in this model of congenital sucrase-isomaltase deficiency, reduces blood glucose response to starch feeding. Supplementing the diet with oral recombinant glucoamylase significantly improved starch digestion in the sucrase-deficient shrew.

Alcoholic fermentation of sorghum and other grains by using a fungal amylase

Energy Technology Data Exchange (ETDEWEB)

Blaisten, R J

1961-01-01

Destilasa is the trade ame of a fungal ..gamma..-amylase obtained from a strain of Aspergillus awamori for use in grain distilleries in Argentina. Using sorghum mash, 57% starch, 2 to 5% Destilasa gave fermentation efficiencies from 76 to 94%, malt 78%, acid conversion 75%. Other starchy materials tested were rye, potatoes, and sweet potatoes. Cooking and saccharification procedures were given in detail for corn, sorghum, and rye. An industrial procedure was outlined in detail and might be applicable to alcohol distilleries using sugar cane.

Structure based protein engineering of Bacillus stearothermophilus {alpha}-amylase: toward a new substrate specificity

Energy Technology Data Exchange (ETDEWEB)

Rasera, Ana Claudia [Sao Paulo Univ., SP (Brazil). Inst. de Ciencias Biomedicas; Iulek, Jorge [Universidade Estadual de Ponta Grossa, PR (Brazil). Inst. de Quimica; Delboni, Luis Fernando; Barbosa, Valma Martins Barbosa [Parana Univ., Curitiba, PR (Brazil). Dept. de Bioquimica

1997-12-31

Full text. Structural similarity is observed in all members of {alpha}-amylase family but different products are generated during hydrolysis of starch due to different affinities for intermediate dextrins. In order to understand the structural determinants for this property and to introduce different specificity to {alpha}-amylase of Bacillus stearothermophilus we intend to solve the three dimensional structure by X-ray crystallography of the native protein by using synchrotron radiation at Brazilian National Synchrotron Light Laboratory (LNLS). Protein was over expressed in E. coli, purified and crystallization experiments were carried out by using sparse matrix Crystal Screen and Crystal Screen II from Hampton Research (Laguna Hills, CA, USA). Several condition have produced crystals with some defined characteristic: MDP seems to be important to the crystallization: the preferential pH is around 7.5 with organic buffer (HEPES); organic solvent as 2-propanol seems to be also important for the crystallization. On those condition crystals appeared as cluster of needles or small crystals with high number of nucleation. New conditions are being prepared to improve the site and quality of crystals. Data collection of native of Bacillus stearothermophilus {alpha}-amylase will e done at Protein Crystallography Station at LNLS. Crystal structure of mutated {alpha}-amylase bu site direct mutagenesis of residues suggested by the native crystal structure will be obtained. Co-crystallization of Bacillus stearothermophilus {alpha}-amylase and oligosaccharide will be carried out to identify residues involved in the binding site to plan new mutation. In another series of mutation the putative binding site residues, once identified, will be mutated to residues observed in TAKA amylase to confer different specificity to {alpha}-amylase. Based on the available TAKA amylase structure, in the primary sequence homology and in the three dimensional model of Bacillus stearothermophilus

Structure based protein engineering of Bacillus stearothermophilus α-amylase: toward a new substrate specificity

International Nuclear Information System (INIS)

Rasera, Ana Claudia; Iulek, Jorge; Delboni, Luis Fernando; Barbosa, Valma Martins Barbosa

1997-01-01

Full text. Structural similarity is observed in all members of α-amylase family but different products are generated during hydrolysis of starch due to different affinities for intermediate dextrins. In order to understand the structural determinants for this property and to introduce different specificity to α-amylase of Bacillus stearothermophilus we intend to solve the three dimensional structure by X-ray crystallography of the native protein by using synchrotron radiation at Brazilian National Synchrotron Light Laboratory (LNLS). Protein was over expressed in E. coli, purified and crystallization experiments were carried out by using sparse matrix Crystal Screen and Crystal Screen II from Hampton Research (Laguna Hills, CA, USA). Several condition have produced crystals with some defined characteristic: MDP seems to be important to the crystallization: the preferential pH is around 7.5 with organic buffer (HEPES); organic solvent as 2-propanol seems to be also important for the crystallization. On those condition crystals appeared as cluster of needles or small crystals with high number of nucleation. New conditions are being prepared to improve the site and quality of crystals. Data collection of native of Bacillus stearothermophilus α-amylase will e done at Protein Crystallography Station at LNLS. Crystal structure of mutated α-amylase bu site direct mutagenesis of residues suggested by the native crystal structure will be obtained. Co-crystallization of Bacillus stearothermophilus α-amylase and oligosaccharide will be carried out to identify residues involved in the binding site to plan new mutation. In another series of mutation the putative binding site residues, once identified, will be mutated to residues observed in TAKA amylase to confer different specificity to α-amylase. Based on the available TAKA amylase structure, in the primary sequence homology and in the three dimensional model of Bacillus stearothermophilus α-amylase (using Bacillus

A kinetic model and simulation of starch saccharification and simultaneous ethanol fermentation by amyloglucosidase and Zymomonas mobilis

Energy Technology Data Exchange (ETDEWEB)

Lee, C G [Michigan Univ., Ann Arbor, MI (United States). Dept. of Chemical Engineering; Kim, C H; Rhee, S K [Korea Inst. of Science and Technology, Taejon (Korea, Republic of). Genetic Engineering Research Inst.

1992-07-01

A mathematical model is described for the simultaneous saccharification and ethanol fermentation (SSF) of sago starch using amyloglycosidase (AMG) and Zymomonas mobilis. By introducing the degree of polymerization (DP) of oligosaccharides produced from sago starch treated with {alpha}-amylase, a series of Michaelis-Menten equations was obtained. After determining kinetic parameters from the results of simple experiments and from the subsite mapping theory, this model was adapted to simulate the SSF process. The results of simulation for SSF are in good agreement with experimental results. (orig.).

The effect of process conditions on the alpha-amylolytic hydrolysis of amylopectin potato starch : an experimental design approach

NARCIS (Netherlands)

Marchal, L.M.; Jonkers, J.; Franke, G.T.; Goooijer, de C.D.; Tramper, J.

1999-01-01

The hydrolysis of amylopectin potato starch with Bacillus licheniformis α-amylase (Maxamyl) was studied under industrially relevant conditions (i.e. high dry-weight concentrations). The following ranges of process conditions were chosen and investigated by means of an experimental design: pH [5.6-

The use of alpha-methyl-D-glucoside, a synthetic analogue of maltose, as inducer of amylase by Aspergillus sp in solid-state and submerged fermentations

Directory of Open Access Journals (Sweden)

Fabiana G. Moreira

2001-03-01

Full Text Available The use of a methyl-D-glucoside (alphaMG, a synthetic analogue of maltose, as carbon source and inducer of amylase synthesis to several species of Aspergillus was studied in submerged and solid-state fermentations. Among a group of ten species, A. tamarii, A. fumigatus and A. flavus were able to produce biomass and high specific amylolytic activity in submerged cultures containing alphaMG as the only carbon source. In solid state fermentation, the enrichment of basal wheat bran or corn cob medium with alphaMG increased up to 3 times the production of amylases. In both submerged and solid state fermentations, alphaMG was more effective inducer of amylases than maltose and starch.

The use of a-methyl-D-glucoside, a synthetic analogue of maltose, as inducer of amylase by Aspergillus sp in solid-state and submerged fermentations

Directory of Open Access Journals (Sweden)

Moreira Fabiana G.

2001-01-01

Full Text Available The use of a methyl-D-glucoside (alphaMG, a synthetic analogue of maltose, as carbon source and inducer of amylase synthesis to several species of Aspergillus was studied in submerged and solid-state fermentations. Among a group of ten species, A. tamarii, A. fumigatus and A. flavus were able to produce biomass and high specific amylolytic activity in submerged cultures containing alphaMG as the only carbon source. In solid state fermentation, the enrichment of basal wheat bran or corn cob medium with alphaMG increased up to 3 times the production of amylases. In both submerged and solid state fermentations, alphaMG was more effective inducer of amylases than maltose and starch.

Starch bioengineering affects cereal grain germination and seedling establishment

DEFF Research Database (Denmark)

Shaik, Shahnoor Sultana; Carciofi, Massimiliano; Martens, Helle Juel

2014-01-01

Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule...... structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics...... showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and β-glucan (BG) degradation was stimulated...

The enhanced inhibition of water extract of black tea under baking treatment on α-amylase and α-glucosidase.

Science.gov (United States)

Tong, Da-Peng; Zhu, Ke-Xue; Guo, Xiao-Na; Peng, Wei; Zhou, Hui-Ming

2018-02-01

This paper studied the inhibition of water extract of natural or baked black tea on the activity of α-amylase and α- glucosidase. Baking treatment was found to be one effective way to enhance the inhibition of black tea on both α-amylase and α- glucosidase, and IC 50 of water extract of baked black tea (BBTWE) were 1.213mg/mL and 4.190mg/mL, respectively, while IC 50 of water extract of black tea (BTWE) were 1.723mg/mL and 6.056mg/mL, respectively. This study further studied the mechanism of the effect of water extract on α-amylase and α- glucosidase using HPLC, circular dichroism, and synchronous fluorescence. HPLC analysis of tea polyphenols showed that the content of tea polyphenols with low polarity increased after baking. In addition, BBTWE had higer abilty on decreasing the hydrophobicity of tryptophan residues than BTWE for both α-amylase and α- glucosidase.The increase of α-helix proportion of α-amylase when treated with BBTWE was more obvious than that when treated with BTWE. In a word, thermal process of baked foods may be beneficial for tea polyphenols to reduce the rate of starch digestion. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of Salivary Cortisol and α-amylase Levels and Psychological Profiles in Patients with Burning Mouth Syndrome.

Science.gov (United States)

Nosratzehi, Tahereh; Salimi, Saeedeh; Parvaee, Azadeh

2017-05-01

The aim of the study was to compare salivary cortisol and α-amylase levels and psychological profiles in patients with burning mouth syndrome (BMS) and healthy subjects. Spitting method was used to collect unstimulated salivary. Salivary cortisol and α-amylase levels were determined using ELISA and the Caraway starch-iodine technique. SLC-90 questionnaire was used to determine the psychological profiles. The difference between mean of salivary cortisol levels in patients with BMS and in healthy subjects was not significant (4.50 ± 3.68 ng/mL vs. 3.69 ± 3.07 ng/mL, p = 0.377). The difference between mean of α-amylase levels in the BMS patients and healthy subjects was significant (351.68 ± 142.5 and 146.22 ± 130.4, p = 0.001). Note that, 83.4% and 18% of the patients in the case and control groups had psychological problems (p = 0.001). The results showed higher salivary levels of cortisol and α-amylase in patients with BMS compared to healthy individuals. Psychological problem was prevalent in patients. © 2017 Special Care Dentistry Association and Wiley Periodicals, Inc.

ALPHA-AMYLASE PRODUCTION FROM Aspergillus oryzae M BY SUBMERGED FERMENTATION

Directory of Open Access Journals (Sweden)

Suleimenova

2016-08-01

Full Text Available The main goal of present study was implementation of the Aspergillus oryzae M strain improved technology using earlier developed method of microorganism selection. 8 pure strains of Aspergillus fungi were screened for the production of extra cellular alpha-amylase using agar medium with starch as a substrate and incubated for 72h at 30 ºС. Zone of clearance was observed for screening of the amylolytic fungi (in mm. Aspergillus oryzae M has demonstrated the highest zone of clearance. Aspergillus oryzae M was cultivated for 42 days in submerged conditions of growth using new method of fungal cultivation. This method based on immobilizing enzymes producers on solid career in submerged conditions of growth gives the way to improve quality of filtrates, which remain clear, does not require additional filtering and easily separated from the mycelium. Moreover, it allows to prolong the process of fungal cultivation and to maintain high enzymatic activity for a long period of time. Presented method allowed increasing alpha-amylase production from 321 U/ml (before immobilization to 502 U/ml (after immobilization.

Characterization of a digestive α-amylase in the larvae of Pieris brassicae L. (Lepidoptera: Pieridae

Directory of Open Access Journals (Sweden)

Arash eZibaee

2016-03-01

Full Text Available The current study deals with a digestive α-amylase in the larvae of Pieris brassicae L. through purification, enzymatic characterization, gene expression and in vivo effect of a specific inhibitor, Acarbose. Although α-amylase activity was the highest in the whole gut homogenate of larvae but compartmentalization of amylolytic activity showed an equal activity in posterior midgut (PM and anterior midgut (AM. A three step purification using ammonium sulfate, Sepharyl G-100 and DEAE-Cellulose Fast flow revealed an enzyme with a specific activity of 5.18 U/mg, recovery of 13.20, purification fold of 19.25 and molecular weight of 88 kDa. The purified α-amylase had the highest activity at optimal pH and temperature of 8 and 35 ºC. Also, the enzyme had Vmax values of 4.64 and 3.02 U/mg protein and Km values of 1.37 and 1.74% using starch and glycogen as substrates, respectively. Different concentrations of acarbose, ethylenediamine tetraacetic acid and ethylene glycol-bis (β-aminoethylether N, N, N′, N′-tetraacetic acid significantly decreased activity of the purified α-amylase. The 4th instar larvae of P. brassicae were fed on the treated leaves of Raphanus sativus L. with 0.22 mM of Acarbose to find in vivo effects on nutritional indices, α-amylase activity and gene expression. The significant differences were only found in conversion efficiency of digested food, relative growth rate and metabolic cost of control and fed larvae on Acarbose. Also, amylolytic activity significantly decreased in the treated larvae by both biochemical and native-PAGE experiments. Results of RT-PCR revealed a gene with 621 bp length responsible for α-amylase expression that had 75% identity with Papilio xuthus and P. polytes. Finally, qRT-PCR revealed higher expression of α-amylase in control larvae compared to acarbose-fed ones.

Supplementation of Carbohydrate to Enhance the α-amylase Production by Bacillus licheniformis ATCC 6346 in Presence of Seed Cakes

Directory of Open Access Journals (Sweden)

Vengadaramana, A.

2012-01-01

Full Text Available Aims: The effect of carbohydrate and amino acids on the production of a-amylase by Bacillus licheniformis ATCC 6346 was investigated. Methodology and results: To find out the influence of carbohydrate the total carbohydrate content of the medium containing different concentration (2-18 g/L of defatted seed cake powder of sesamum and mustard containing medium was kept constant by the addition of soluble starch separately. The highest a-amylase activity obtained in the medium containing 18g/L mustard (59.11+b1.48 U/mL and sesamum seed cake powder (55.23+b1.55 U/mL. The results indicated that under these conditions the carbohydrate content had no effect on the production of a-amylase. Effect of amino acids (0.2g/L of glycine, methionine, proline, lysine, leucine, threonine, serine, arginine, alanine, glutamic acid, tryptophan, glutamine, asparagine, histidine, valine, phenylalanine, isoleucine and mixture of amino acids on the production of a-amylase in fermentation medium was investigated. Among the different amino acids supplemented, eight amino acids improved the a-amylase production but casaminoacids slightly inhibited the enzyme production. In presence of tryptophan highest enzyme activity was obtained than control. Conclusion, significance and impact of study: In these study amino acids especially tryptophan takes part in a particular role rather than carbohydrate in the production of a-amylase from B. licheniformis ATCC 6346.