Abstract in english Cassava pulp was fermented with pure strains of Saccharomyces cerevisae and two bacteria namely Lactobacillus delbruckii and Lactobacillus coryneformis for 3 days. The squeezed liquid from the fermented pulp was used to ferment cassava peels for 7 days. Analysis of the dried fermented peels revealed that there was a significant (P (more) red with the unfermented cassava peel (8.2%). Moreover, the treatment equally brought about a significant (P

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

This study shows that Rhizopus oryzae is capable of directly utilizing cassava pulp alone to L-lactic acid in solid state fermentation (SSF). pH control at 6.0 helped prevent end product inhibition. Increasing lactate titer was observed at the higher initial moistened water due to the higher degree of substrate swelling and hydrolysis. With shaking, limited ethanol production but no change in lactate titer was observed. Rigorous shaking gave better oxygen transfer but presumably caused cell damage leading to substrate utilization through the biosynthesis route. Supplementing cassava pulp with nitrogen enhanced growth but not lactate production. Under the optimal conditions, R. oryzae converted the sole cassava pulp into lactic acid at the titer of 206.20 mg per g initial dry pulp. With the help of commercial cellulase and glucoamylase, the dramatically increasing lactate titer of 463.18 mg per g initial dry pulp was achieved via SSF. PMID:22476767

Sweet cassava from the Cook Islands was washed, peeled, and hammer milled. It was spread on metal trays to a thickness of about 2 mm and kept in an enclosed transparent tunnel for 6 h in the sun to encourage endogenous linamarase activity. The end covers were removed and normal solar tunnel drying continued for 2 to 3 days or until quite dry. The temperature of the cassava pulp, the relative humidity in the tunnel, and weight of the cassava pulp were measured at regular intervals. It was found that the temperature of the cassava pulp and relative humidity in the enclosed tunnel rose rapidly to a level that caused the maximum level of linamarase activity. At the end of the 6-h period of fermentation, the total cyanide levels had reduced to well below the 10 ppm on a dry matte...

The processes of separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) were employed using Saccharomyces cerevisiae for the production of ethanol from cassava pulp without any pretreatment. A combination of amylase, cellulase, cellobiase, and glucoamylase produced the highest levels of ethanol production in both the SHF and the SSF method. A temperature of 37 °C, a pH of 5.0, and an inoculum size of 6% were the optimum conditions for SSF. For the batch process at a pulp concentration of 20%, ethanol production levels from SHF and SSF were the highest, at 23.51 and 34.67 g L?1 respectively, but in the fed-batch process, the levels of ethanol production from SHF and SSF rose to 29.39 and 43.25 g L?1 respectively, which were 25% and 24.7% higher than those of the batch process. Thus SSF using the fed-batch provided a more efficient method for the utilization of cassava pulp.   

Detoxification of cassava cultivars (30572 TMS and 30555 TMS) during their traditional methods of processing to produce gari and cassava flour has been investigated. The HCN quantitative determination was done using the enzymatic assay. Fermentation of cassava pulp for 96 hours during cassava processing for gari reduced the HCN by 22 ppm (52.4 percent) and 20 ppm (57.3 percent) for 30572 TMS and 30555 TMS respectively. There was no significant difference (P > 0.05) in the HCN content of the two cultivars. Soaking of the sliced cassava tissue for 24 hours in cassava flour production prior to sundrying resulted in 16 ppm (38.1 percent) and 15 ppm (38.4 percent) HCN reduction for 30572 TMS and 30555 TMS respectively. HCN loss during sundrying was 6 ppm (14.3 percent) and 5 ppm (12.8 percent) for the two cultivars. There was significantly (P processing of gari than cassava flour. The residual cyanide in gari was 12 ppm for 30572 TMS and 10 ppm for 30555 TMS and that in the flour was 20 ppm for 30572 and 19 ppm for 30555 TMS. PMID:8882371

Cassava tuber skin is a by-product of cassava chip industry, fermented by using mixed mineral (solid media) and Aspergillus niger. The objectives of this research was to know the increasing of nutrient value of cassava tuber skin toward the period of fermentation and several level of inoculums giv...

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.

Comparative studies were carried out on the ability of pure strain of Rhizopus oryzae and Saccharomyces cerevisae to alter the nutritional quality of cassava flour produced from low- and medium-cyanide variety of cassava tuber. Low- and medium-cyanide variety of cassava tubers were collected from International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. These tubers were washed, peeled, grated and aseptically inoculated with pure strains of Rhizopus oryzae and Saccharomyce cerevisae in nutrient solution respectively, before allowing them to ferment aerobically for 3 days. The fermented mash was subsequently dried and milled into cassava flour. Subsequently, the proximate, mineral and the antinutrinet composition of the cassava flour were determined. The results of the study revealed that the unfermented flour from low-cyanide cassava variety had higher protein, fibre, ash, fat, Ca, Na and K; while those produced from medium-cyanide variety, had higher antinutrinet (tannin, cyanide & phytate), Zn, Mg and Fe content. However, solid substrate fermentation of the cassava mash using Rhizopus oryzae and Saccharomyces cerevisae respectively caused a significant (P flour produced from low-cyanide cassava variety. In addition, Saccharomyces cerevisae fermentation brought about a higher increase in the nutrient content than Rhizopus oryzae fermentation. Conversely, fermentation of the cassava caused a significant decrease (P flour; although, the level of decrease was more in the flour produced from low-cyanide variety than medium-cyanide variety. Nevertheless, there was no significant difference (P > 0.05) in the ability of the fungi to decrease the antinutrient (except phytate) of the cassava flour. Furthermore, micro-fungi fermentation did not cause a significant change (P > 0.05) in mineral content (except Mg and K) of the fermented cassava flour. In conclusion, unfermented cassava flour produced from low-cyanide cassava tubers had high nutrient composition and low antinutrient content and more susceptible to micro-fungi nutrient enrichment and detoxification than medium-cyanide variety. Furthermore, Saccharomyces cerevisae was more efficient in the nutrient enrichment of the cassava flour than Rhizopus oryzae. PMID:18087867

Some original observations have been made on the process of cassava fermentation to produce 'foofoo', a local nigerian diet. During the period of fermentation the pH of the fermenting liquor decreases from 6.1 to 3.4 at the end of the 6th day. The change in pH is uniform throughout the fermentation period. Decreases in dry weight of the fermenting cassava have been recorded; there is a very rapid decline during the third and fourth days of fermentation. Free reducing sugars decrease drastically within the first and second days. Total sugar concentration which is an indication of the starch content of the cassava also declines with fermentation time, and more so during the third and fourth days. Protein concentration in the liquor increases very rapidly during the first and second days of fermentation. It is believed that cassava protein is converted to microbial protein.

Raw cassava root starch was transformed into ethanol in a one-step process of fermentation, in which are combined the conventional processes of liquefaction, saccharification, and fermentation to alcohol. Aspergillus awamori NRRL 3112 and Aspergillus niger were cultivated on wheat bran and used as Koji enzymes. Commercial A. niger amyloglucosidase was also used in this experiment. A raw cassava root homogenate-enzymes-yeast mixture fermented optimally at pH 3.5 and 30/degree/C, for five days and produced ethanol. Alcohol yields from raw cassava roots were between 82.3 and 99.6%. Fungal Koji enzymes effectively decreased the viscosity of cassava root fermentation mashes during incubation. Commercial A. niger amyloglucosidase decreased the viscosity slightly. Reduction of viscosity of fermentation mashes was 40, 84, and 93% by commercial amyloglucosidase, A. awamori, and A. niger enzymes, respectively. The reduction of viscosity of fermentation mashes is probably due to the hydrolysis of pentosans by Koji enzymes. 12 refs.

ABSTRACT The effects of lactic acid fermentation of cassava on the functional and sensory characteristic of fufu flour were investigated. Two strains of Lactobacillus plantarum were used as starter cultures for the fermentation of cassava to fufu for 96 h. The resultant wet fufu samples were dried at 65C in a cabinet dryer for 48 h, and were analyzed for functional and sensory characteristics. Fermentation reduced the water-binding capacity of the fufu flour from 176.6% to between 118 and 125%. The pasting characteristics of the traditional and starter culture-fermented fufu flour samples were not significantly different from that of the unfermented cassava flour. When subjected to sensory evaluation, the traditional and starter culture-fermented cassava fufu flour were not significantly d...

Cassava chips (cassava balls, and cassava pellets) are derived cassava products traditionally produced by farmers in sub-Saharan Africa following fermentation, and drying of fresh roots of cassava, and are widely consumed in Cameroon. Once produced, this food commodity can be stored for more than two months and contaminated by a wide array of harmful microbes. In order to assess persistence of toxigenic fungi in cassava chips, aflatoxin-producing fungi (Aspergillus flavus, Aspergillus nomius, and Aspergillus parasiticus) and aflatoxins were contrasted at regular intervals in home-stored cassava chips collected in two locations of southern Cameroon throughout a two-month monitoring period. Three hundred and forty-six isolates of aflatoxin-producing fungi were found to be associated with all...

Summary Tropical root and tuber crops [cassava, sweet potato, yams, colocasia (taro), etc] are important staples for food security for about a fifth of the world population. Bulk of cassava in Africa and Latin America are processed into fermented foods and food additives such as organic (acetic, citric and lactic) acids, mono-sodium glutamate, etc. The fermented foods from cassava are gari, fufu, lafun, chickwanghe, agbelima, attieke and kivunde in Africa, tape in Asia and `cheese'bread, and `coated peanut' in Latin America. Lactic acid bacteria and yeasts are the major group of micro-organisms associated with cassava fermentation. Similarly, sweet potatoes can be fermented into soy sauce, vinegar, lacto-juices, lacto-pickles and sochu (an alcoholic drink produced in Japan), and yams into ...

The overall kinetics of retting, a spontaneous fermentation of cassava roots performed in central Africa, was investigated in terms of microbial-population evolution and biochemical and physicochemical parameters. During the traditional process, endogenous cyanogens were almost totally degraded, pla...

A two-step process of sequential anaerobic (dark) and photo-heterotrophic fermentation was employed to produce hydrogen from cassava and food waste. In dark fermentation, the average yield of hydrogen was approximately 199 ml H{sub 2} g{sup -1} cassava and 220 ml H{sub 2} g{sup -1} food waste. In subsequent photo-fermentation, the average yield of hydrogen from the effluent of dark fermentation was approximately 611 ml H{sub 2} g{sup -1} cassava and 451 ml H{sub 2} g{sup -1} food waste. The total hydrogen yield in the two-step process was estimated as 810 ml H{sub 2} g{sup -1} cassava and 671 ml H{sub 2} g{sup -1} food waste. Meanwhile, the COD decreased greatly with a removal efficiency of 84.3% in cassava batch and 80.2% in food waste batch. These results demonstrate that cassava and food waste could be ideal substrates for bio-hydrogen production. And a two-step process combining dark fermentation and photo-fermentation was highly improving both bio-hydrogen production and removal of substrates and fatty acids. (author)

The cyanide levels were followed during protein enrichment of cassava by the fungus Aspergilus oryzae. The total cyanogen level decreased by 158 mg/kg dry weight to 54.2 mg/kg dry weight as a result of the whole process including fermentation. The cyanogenic glucoside level decreased by 88% during the fermentation process while acetone cyanohydrin was retained in the cassava. The prefermentation processing which involved crushing, sundrying and milling the cassava into flour, reduced the total cyanogen levels by 40%. The process resulted in considerable reduction in the cyanogenic content of the product. PMID:7712337

When fermenting on cassava (15-25%, w/v) with Clostridium acetobutylicum ATCC824, a severe delay (18-40h) was observed in the phase shift from acidogenesis to solventogenesis, compared to the cases of fermenting on corn. By adding yeast extract (2.5g/L-broth) into cassava meal medium when the delay appeared, the phase shift was triggered and fermentation performances were consequently improved. Total butanol concentrations/butanol productivities, compared to those with cassava substrate alone, increased 15%/80% in traditional fermentation while 86%/79% in extractive fermentation using oleyl alcohol as the extractant, and reached the equivalent levels of those using corn substrate. Analysis of genetic transcriptional levels and measurements of free amino acids in the broth demonstrated that timely and adequate addition of yeast extract could promote phase shift by increasing transcriptional level of ctfAB to 16-fold, and indirectly enhance butanol synthesis through accelerating the accumulation of histidine and aspartic acid families. PMID:23023236

Cassava pulp residue and rice straw were used as a precursor for pretreatment with ionic liquids to study the effects of pretreatment conditions on product yield and properties. Cassava pulp residue is a potential biomass in the bioconversion process due to it requiring mild pretreatment conditions while providing a high sugar conversion. The maximum sugar conversion and lignin extraction are attained from pretreatment of biomasses with particle size of 1-Ethyl-3-methylimidazolium diethyl phosphate>1,3-Dimethylimidazolium methyl sulfate. The increase of pretreatment temperature from ...

Fermentation of cassava is an important processing technique followed in different parts of the world. Although fermentation is known to bring about vast changes in the physicochemical and functional properties of the tubers, attempts have seldom been made to consolidate and critically analyze the available information. Glaring inconsistencies and contradictions noticeable in some of the results reflect the differences and variations in the artisanal processes followed in the preparation of these products. It also stresses the need for a systematic study of not only the quoted products, but also a number of other fermented cassava products that have not been well documented. PMID:9526681

Mixed bacteria were used to improve hydrogen yield from cassava starch in combination of dark and photo fermentation. In dark fermentation, mixed anaerobic bacteria (mainly Clostridium species) were used to produce hydrogen from cassava starch. Substrate concentration, fermentation temperature and pH were optimized as 10.4 g/l, 31 ?C and 6.3 by response surface methodology (RSM). The maximum hydrogen yield and production rate in dark fermentation were 351 ml H2/g starch (2.53 mol H2/mol hexose) and 334.8 ml H2/l/h, respectively. In photo fermentation, immobilized mixed photosynthetic bacteria (PSB, mainly Rhodopseudomonas palustris species) were used to produce hydrogen from soluble metabolite products (SMP, mainly acetate and butyrate) of dark fermentation. The maximum hydrogen yield in p...

The production of ethanol as an alternative motor fuel is dealt with. Attention is paid to biological and biochemical aspects (yeasts, fermentation processes), raw materials (sugar cane, cassava, potatoes, cereals) and the processing (fermentation conditions, distillation). Ethanol can substitute petrol or diesel oil by mixing it with the original fuel or by using pure ethanol instead of petroleum products. In Brazil a national program is started to stimulate the construction of ethanol plants and the cultivation of sugar cane and cassava and thus gradually substitute petrol and diesel oil by ethanol. Energy balance for alcohol fuel is favourable when sugar cane or cassava is used as raw material. When cereals, potatoes or sugar beet is used, the energy balance is negative. Utilization of alcohol as motor fuel is especially fit for developing countries because of the relatively simplicity while large areas are available for the cultivation of sugar cane or cassava.

Natural microbial consortia from hot spring samples were used to developed thermophilic mixed cultures for biohydrogen production from cassava starch processing wastewater (CSPW). Significant hydrogen production potentials were obtained from three thermophilic mixed cultures namely PK, SW and PR with maximum hydrogen production yields of 249.3, 180 and 124.9 mL H2/g starch, respectively from raw cassava starch and 252.4, 224.4 and 165.4 mL H2/g starch, respectively from gelatinized cassava starch. Acetic acid-ethanol and acetic-lactic acid type fermentation were observed in cassava starch fermentation, based on three thermophilic mixed cultures performance. The thermophilic mixed cultures PK, SW and PR exhibited the maximum hydrogen yield of 287, 264 and 232 mL H2/g starch in CSPW, respect...

We previously demonstrated that the quantity of beta-carotene (BC) partitioning in mixed micelles during simulated small intestinal digestion, i.e., the bioaccessibility, of boiled cassava is highly correlated with the BC content of different cultivars. However, cassava is also traditionally prepared by fermentation and roasting. These different methods of preparation have the potential to affect both the retention and bioaccessibility of BC. Here, we first compared retention of BC in boiled cassava, gari (fermentation followed by roasting), and fufu (fermentation followed by sieving and cooking into a paste) prepared from roots of three cultivars. BC content in unprocessed cultivars ranged from 6-8 microg/g wet weight, with cis isomers accounting for approximately one-third of total BC. Apparent retention of BC was approximately 90% for boiled cassava and fufu. In contrast, roasting fermented cassava at 195 degrees C for 20 min to prepare gari decreased BC content by 90%. Retention was increased to 63% when temperature was decreased to 165 degrees C and roasting was limited to 10 min. Processing was also associated with a decline in all-trans-BC and concomitant increase in 13-cis-BC. The efficiency of micellarization of all-trans and cis isomers of BC during simulated digestion was 25-30% for boiled cassava and gari and independent of cultivar. However, micellarization of BC isomers during digestion of fufu was only 12-15% (P cassava products prepared according to traditional processing methods suggest that gari and fufu may provide less retinol activity equivalents than isocaloric intake of boiled cassava. PMID:19199597

An artisanal static process for protein enrichment of cassava by solid-state fermentation, developed in laboratory and tested on pilot units in Burundi (Central Africa), provides enriched cassava containing 10.7% of dry matter protein versus 1% before fermentation. Cassava chips, processed into granules of 2-4-mm diameter, are moistened (40% water content) and steamed. After cooling to 40 degrees C, cassava is mixed with a nutritive solution containing the inoculum (Rhizopus oryzae, strain MUCL 28627) and providing the following per 100 g dry matter: 3.4 g urea, 1.5 g KH/sub 2/PO/sub 4/, O.8 g MgSO/sub 4/.7H/sub 2/O, and 22.7 g citric acid. For the fermentation, cassava, with circa 60% moisture content, is spread in a thin layer (2-3 cm thick) on perforated trays and slid into an aerated humidified enclosure. The incubation lasts more or less 65 hours. The production of protein enriched cassava is 3.26 kg dry matter/square m tray. The effects of the variation of the nutritive solution composition and the inoculum conservation period on the protein production are equally discussed. (Refs. 37).

Abstract Aims: To select appropriate micro-organisms to be used as starter culture for reliable and reproducible fermentation of Lafun. Methods and Results: A total of 22 cultures consisting of yeast, lactic acid bacteria (LAB) and Bacillus cereus strains predominant in traditionally fermented cassava during Lafun processing were tested as potential starter cultures. In an initial screening, Saccharomyces cerevisiae 2Y48P22, Lactobacillus fermentum 2L48P21, Lactobacillus plantarum 1L48P35 and B. cereus 2B24P31 were found to be the most promising of the cultures and were subsequently tested in different combinations as mixed starter cultures to ferment submerged cassava roots. Saccharomyces cerevisiae, inoculated singly or combined with B. cereus, gave the softest cassava root after 48 h of...

Lactobacillus manihotivorans has been reported as one of the dominant species in cassava sour starch production process. Seven isolates that have previously been identified as belonging to this species were studied in the present work. Their molecular and phenotypic characteristics showed higher strain diversity than previously described. Differences were found in their fermentation profiles, whereas no major differences were observed in properties related to processing conditions (salt concentration, pH, temperature), or in potential functional properties (bile salt and pH 2.0 tolerance). Among the main characteristics of interest for the fermentation of cereals or cassava, blended or not with legumes, six out of seven strains were amylolytic and raffinose was fermented by all strains. Strains OND 32T and OLB 7 fermented the broadest range of carbohydrates. Most of the strains contained plasmids. Plasmid curing changed their phenotypic characteristics, particularly those of strain OND 32T, which, in addition, lost its starch and raffinose fermentation ability. PMID:12927722

Studies have been conducted in a gas circulation type fermentor in order to characterize the ethanol fermentation of uncooked cassava starch with Rhizopus koji. Results showed that ethanol concentration reached 13-14% (v/v) in 4-day broth, and the maximum productivity of ethanol was 2.3 g ethanol/l broth h. This productivity was about 50% compared to the productivity of a glucose-yeast system. Ethanol yield reached 83.5-72.3% of the theoretical yield for the cassava starch used. The fermentor used in the present work has been proven by experiment to be suitable for ethanol fermentation of the broth with solid substrate. 10 references.

The recovery of ethanol fermented pulp of tapioca fibrous residues by hydraulic pressing in three stages with interstage water addition lead to 79.68% relative recovery but the concentration of the ethanol in the pooled extract was nearly 60.53% of that present in the fermented pulp. The lower concentration of ethanol in extract obtained by percolation technique and poor extraction efficiency associated with other recovery processes are unacceptable from economic point of view. (orig.).

Using only wheat bran koji from the Rhizopus strain, raw cassava starch and casava pellets converted reasonably well to alcohol (ethanol) without cooking at 35/sup 0/C and pH 4.5-5.0. When the initial broth contained 30 g raw cassava starch, 10 g Rhizopus sp. koji, and 100 mL tap water, 12.1 g of alcohol was recovered by final distillation from fermented broth. In this case, 12.1 g alcohol corresponds to an 85.5% conversion rate based on the theoretical value of the starch content. When the initial broth contained 40 g cassava starch, 14.1 g of alcohol was recovered, where 14.1 g corresponds to a 74.5% conversion rate. The alcoholic fermentation process described in the present work is considered more effective and reasonable than the process using raw starch without cooking reported until now, since the new process makes it unnecessary to add yeast cells and glucoamylase preparation.

For the eventual alcohol fermentation of uncooked cassava starch, a saccharification process was examined consisting of steeping in 0.5 N HCl solution (sample weight/acid volume=1/2) at 60/sup 0/C for 12 h, followed by the combined actions of ..cap alpha..-amylase and glucoamylase. Scanning electron microscopy showed that the acid steeping helped change the starch structure to a form more susceptible to ..cap alpha..-amylase and glucoamylase. This acid steeping overrode the reported macerating effect of pectin depolymerase on raw cassava starch mash. The ethanol yield from cassava starch treated under the conditions described was 95% after fermentation for 3 days at 30/sup 0/G with Saccharomyces cerevisiae.

Yeast strains capable of fermenting starch and dextrin to ethanol were isolated from samples collected from Brazilian factories in which cassava flour is produced. Considerable alcohol production was observed for all the strains selected. One strain (DI-10) fermented starch rapidly and secreted 5 times as much amylolytic enzyme than that observed for Schwanniomyces alluvius UCD 54-83. This strain and three other similar isolates were classified as Saccharomyces cerevisiae var. diastaticus by morphological and physiological characteristics and molecular taxonomy.

The extraction, hydrolysis, fermentation, and distillation processes using sugar cane, sugar beets, Jerusalem artichokes, green crops, grains, cassava, potatoes, yams, or cellulose as feedstock are outlined. The use of process wastes as building materials, animal feeds, fertilizers, or sources of process energy is also discussed. A comparison is made of the estimated production costs of six ethanol plants using different feedstocks. (CKK)

Cassava fibrous waste is generated during starch manufactured as a solid waste used mainly for animal feeding. The process of the alcohol production from cassava fibrous waste using pectinase as a complementary enzyme in the hydrolysis process was technically and economically analyzed in this work. The addition of nutrients on the fermentation wort was also analyzed. The fibrous waste, the final fibrous residue after hydrolysis and the fermentation wort were characterized in their physical-chemistry composition and profile of sugars. The cassava fibrous waste had 80% starch, 11.5% fiber, 1.14% ash, 0,85% protein and 0.45% of the sugars. In the hydrolysis process it was obtained a conversion of 86.31 of initial starch and 80% of the total sugars yield considered as 100%. The solid fibrous residue generated after hydrolysis had 37% of the starch, 30% of total sugars and 30% of fibers in dry basis. The data indicated that 75% of the raw material was hydrolyzed. The fermentation wort had 13 deg Brix of extract and it was not necessary to concentrate it. The data showed that the maximum of alcohol is formed after 48 h of fermentation and the addition of nutrients reduced the fermentation time in 8 hours. There was not expressive difference in the fermentation yield with and without addition of nutrients. The average yield of the conversion starch to alcohol was 51.6%. The cost analysis indicated that this process is economically possible. (author)

To investigate the effect of fermented black soybean pulp on serum lipid metabolism and osteoporosis in ovariectomized rats, Sprague-Dawley rats were divided into 4 groups: sham-operated control group, ovariectomized control group, ovariectomized group treated with black soybean pulp (BSP), and ovariectomized group treated with fermented black soybean pulp (FBSP). Rats were fed experimental diets for 8 weeks after ovariectomy. Compared to the control, FBSP supplemen-tation led to the improving effect for femur weight, abdominal fat, alanine aminotransferase, aspartate aminotransferase activity, hepatic lipid levels, and thiobarbituric acid reactive substances. Also, serum HDL-cholesterol, estradiol levels, serum alkaline phosphatase activity, and osteocalcin levels in the FBSP group were s...

Cassava pulp residue and rice straw were used as a precursor for pretreatment with ionic liquids to study the effects of pretreatment conditions on product yield and properties. Cassava pulp residue is a potential biomass in the bioconversion process due to it requiring mild pretreatment conditions while providing a high sugar conversion. The maximum sugar conversion and lignin extraction are attained from pretreatment of biomasses with particle size of 1-Ethyl-3-methylimidazolium diethyl phosphate>1,3-Dimethylimidazolium methyl sulfate. The increase of pretreatment temperature from 25 to 120°C and decrease of biomass particle size renders higher sugar conversion, lignin extraction and lower crystallinity index. However, pretreatment at temperatures higher than 120°C shows a sharp decline of regenerated biomass yield, sugar conversion and lignin extraction and giving higher crystallinity index at pretreatment temperature of 180°C. PMID:22366610

Abstract in portuguese Este trabalho teve como objetivo prolongar a vida pós-colheita de melões do tipo amarelo cv. AF-682, por meio da atmosfera modificada obtida com filme plástico de PVC e filmes comestíveis à base de cera de carnaúba (50%) e fécula de mandioca (1, 2 e 3%). Para o revestimento dos frutos com embalagem plástica utilizou-se filme de PVC com 10 mm de espessura, aderente e esticável, colocado em camada única, na superfície de cada fruto. Após serem revestidos pelos f (more) ilmes os frutos foram armazenados em temperatura ambiente de 29± 2ºC e 64±1% UR por 20 dias, sendo em intervalos de cinco dias submetidos às avaliações: massa individual, firmeza da polpa, teor de sólidos solúveis totais, acidez titulável e pH. Utilizou-se delineamento inteiramente casualizado com seis repetições em esquema fatorial 6x4, sendo 6 tratamentos de conservação e 4 períodos de armazenamento. Nenhum dos tratamentos avaliados é recomendável para aumentar a conservação pós-colheita de melão amarelo. Os frutos revestidos com fécula de mandioca a 3% e filme de PVC apresentaram processo iniciais característicos de fermentação e podridão a partir de 15 dias de armazenamento em temperatura ambiente. Abstract in english This work aimed to extend the postharvest life of yellow melons cv. AF-682 through modified atmosphere techniques obtained with PVC film and edible films such as carnauba wax (50%) and cassava starch (1, 2 and 3%). Fruits were wrapped with one layer of adherent and stretchable PVC film with 10 mm width. After covering, fruits were stored at 29± 2ºC and 64±1% UR for 20 days. At a 5-day interval, fruits were evaluated for individual weight, pulp firmness, total soluble s (more) olids content, titratable acidity and pH. The trial was carried out in a complete randomized design, with six replications in a factorial scheme 6x4, with six treatments and four storage periods. The use of PVC film and edible films are not recommended to extend postharvest conservation of yellow melon cv. AF-682. The fruits covered with 3% of cassava starch and PVC film presented initial process of fermentation and rot after 15 days of storage at 29ºC.

Cassava (Manihot esculenta Crantz) is an important tropical root crop providing energy to about 500 million people. The presence of the two cyanogenic glycosides, linamarin and lotaustralin, in cassava is a major factor limiting its use as food or feed. Traditional processing techniques practiced in cassava production are known to reduce cyanide in tubers and leaves. Drying is the most ubiquitous processing operation in many tropical countries. Sun drying eliminates more cyanide than oven drying because of the prolonged contact time between linamarase and the glucosides in sun drying. Soaking followed by boiling is better than soaking or boiling alone in removing cyanide. Traditional African food products such as gari and fufu are made by a series of operations such as grating, dewatering, fermenting, and roasting. During the various stages of gari manufacture, 80 to 95% cyanide loss occurs. The best processing method for the use of cassava leaves as human food is pounding the leaves and cooking the mash in water. Fermentation, boiling, and ensiling are efficient techniques for removing cyanide from cassava peels. PMID:7576161

A pilot-plant fermenter of 1.8 cubic m total capacity was divided into 3 chambers sunk into the ground and protected by a plastic film dome. The production of biogas from chopped water hyacinth in this fermenter reached 330 L/kg dry matter. The ratio of the biogas heat content to the electric energy used to heat the fermentor reached 1.49. These results are comparable to the methanation of cellulose pulp waste in the same fermenter.

The effect of controlled fermentation processes on the microbial association and biochemical profile of cv. Conservolea naturally black olives processed by the traditional anaerobic method was studied. The different treatments included (a) inoculation with a commercial starter culture of Lactobacillus pentosus, (b) inoculation with a strain of Lactobacillus plantarum isolated from a fermented cassava product and (c) uninoculated spontaneous process. Microbial growth, pH, titratable acidity, organic acids and volatile compounds were monitored throughout the fermentation. The initial microbiota consisted of Gram-negative bacteria, lactic acid bacteria and yeasts. Inhibition of Gram-negative bacteria was evident in all processes. Both starter cultures were effective in establishing an acceler...

A fibrous waste residue (20%) obtained in the manufacture of starch and sago from cassava poses disposal problems. Fermentation studies for the production of alcohol on saccharified waste revealed that enrichment with mineral salts and N is essential. Inoculum size of 24.2 X 10 to the power of 6 cells/50 mL medium was optimal; the highest quantity of alcohol was formed after 96 hours of fermentation. Although the optimum initial sugar concentration in the fermentation medium was approximately 15%, the saccharified waste needed expensive concentration treatment to raise the sugar concentration to its optimum level.

The Tapirapé people of the Tapi'itãwa tribe of Brazil produce several fermented foods and beverages, one of which is called 'cauim'. This beverage usually makes up the main staple food for adults and children. Several substrates are used in its production, including cassava, rice, corn, maize and peanuts. A fermentation using rice and cassava was conducted, and samples were collected at 4-h intervals for microbial analysis. The yeast population was low at the beginning of the fermentation and reached 6.9 x 10(7) CFU mL(-1) after 48 h. During the fermentation process common yeast species were identified by sequencing of the D1/D2 domain of the large-subunit (26S) rRNA gene. The predominant yeast species found was Candida tropicalis. Candida intermedia, Candida parapsilosis, Pichia guilliermondii, Saccharomyces cerevisiae and Trichosporon asahii were also found in high numbers during the fermentation. Exophiala dermatidis, often associated with blastomycosis, was found in the mass before inoculation and during the initial stages of the fermentation. Examination of these indigenous fermented foods may provide clues as to how food production and preservation can be expanded and thereby contribute to improve nutrition in native tribes in the region.

The adaptability of lactic acid bacteria (LAB) and yeasts to sourdoughs prepared from cereals, pseudocereals and cassava was investigated using PCR-DGGE and bacteriological culture combined with rRNA gene sequence analysis. Sourdoughs were prepared either from flours of the cereals wheat, rye, oat, barley, rice, maize, and millet, or from the pseudocereals amaranth, quinoa, and buckwheat, or from cassava, using a starter consisting of various species of LAB and yeasts. Doughs were propagated until a stable microbiota was established. The dominant LAB and yeast species were Lactobacillus fermentum, Lactobacillus helveticus, Lactobacillus paralimentarius, Lactobacillus plantarum, Lactobacillus pontis, Lactobacillus spicheri, Issatchenkia orientalis and Saccharomyces cerevisiae. The proportion of the species within the microbiota varied. L. paralimentarius dominated in the pseudocereal sourdoughs, L. fermentum, L. plantarum and L. spicheri in the cassava sourdough, and L. fermentum, L. helveticus and L. pontis in the cereal sourdoughs. S. cerevisiae constituted the dominating yeast, except for quinoa sourdough, where I. orientalis also reached similar counts, and buckwheat and oat sourdoughs, where no yeasts could be detected. To assess the usefulness of competitive LAB and yeasts as starters, the fermentations were repeated using flours from rice, maize, millet and the pseudocereals, and by starting the dough fermentation with selected dominant strains. At the end of fermentation, most of starter strains belonged to the dominating microbiota. For the rice, millet and quinoa sourdoughs the species composition was similar to that of the prior fermentation, whereas in the other sourdoughs, the composition differed. PMID:19239979

Fermentation of cassava starch hydrolysate with immobilised cells of Saccharomyces cerevisiae (Strain 2177) was carried out. Kieselguhr and brick powder were the substrates used for immobilisation of yeast cells. The pattern of fermentation was followed by the rate of fall in reducing sugar content and the cell growth. The results obtained showed that variations in the immobilised yeast cell preparations did not produce any effect on the rate of reduction of sugars during the fermentation. The final cell densities obtained after 48 h also did not depend on the initial immobilised cell concentration. However it was shown that fermentation could be completed in 48 h. It was also evident from the results that the cells were alive on the support used for immobilisation even after 4-cycles of fermentation. (orig.).

Fusion hybrid yeast, CHFY0321, was obtained by protoplast fusion between non-flocculent-high ethanol fermentative Saccharomyces cerevisiae CHY1011 and flocculent-low ethanol fermentative Saccharomyces bayanus KCCM12633. The hybrid yeast was used together with the parental strains to examine ethanol production in batch fermentation. Under the conditions tested, the fusion hybrid CHFY0321 flocculated to the highest degree and had the capacity to ferment well at pH 4.5 and 32 C. Simultaneous saccharification and fermentation for ethanol production was carried out using a cassava (Manihot esculenta) powder hydrolysate medium containing 19.5% (w v{sup -1}) total sugar in a 5 l lab scale jar fermenter at 32 C for 65 h with an agitation speed of 2 Hz. Under these conditions, CHFY0321 showed the highest flocculating ability and the best fermentation efficiency for ethanol production compared with those of the wild-type parent strains. CHFY0321 gave a final ethanol concentration of 89.8 {+-} 0.13 g l{sup -1}, a volumetric ethanol productivity of 1.38 {+-} 0.13 g l{sup -1} h{sup -1}, and a theoretical yield of 94.2 {+-} 1.58%. These results suggest that CHFY0321 exhibited the fermentation characteristics of S. cerevisiae CHY1011 and the flocculent ability of S. bayanus KCCM12633. Therefore, the strong highly flocculent ethanol fermentative CHFY0321 has potential for improving biotechnological ethanol fermentation processes. (author)

The combination of dark and photo fermentation was studied with cassava starch as the substrate to increase the hydrogen yield and alleviate the environmental pollution. The different raw cassava starch concentrations of 10-25 g/l give different hydrogen yields in the dark fermentation inoculated with the mixed hydrogen-producing bacteria derived from the preheated activated sludge. The maximum hydrogen yield (HY) of 240.4 ml H{sub 2}/g starch is obtained at the starch concentration of 10 g/l and the maximum hydrogen production rate (HPR) of 84.4 ml H{sub 2}/l/h is obtained at the starch concentration of 25 g/l. When the cassava starch, which is gelatinized by heating or hydrolyzed with {alpha}-amylase and glucoamylase, is used as the substrate to produce hydrogen, the maximum HY respectively increases to 258.5 and 276.1 ml H{sub 2}/g starch, and the maximum HPR respectively increases to 172 and 262.4 ml H{sub 2}/l/h. Meanwhile, the lag time ({lambda}) for hydrogen production decreases from 11 h to 8 h and 5 h respectively, and the fermentation duration decreases from 75-110 h to 44-68 h. The metabolite byproducts in the dark fermentation, which are mainly acetate and butyrate, are reused as the substrates in the photo fermentation inoculated with the Rhodopseudomonas palustris bacteria. The maximum HY and HPR are respectively 131.9 ml H{sub 2}/g starch and 16.4 ml H{sub 2}/l/h in the photo fermentation, and the highest utilization ratios of acetate and butyrate are respectively 89.3% and 98.5%. The maximum HY dramatically increases from 240.4 ml H{sub 2}/g starch only in the dark fermentation to 402.3 ml H{sub 2}/g starch in the combined dark and photo fermentation, while the energy conversion efficiency increases from 17.5-18.6% to 26.4-27.1% if only the heat value of cassava starch is considered as the input energy. When the input light energy in the photo fermentation is also taken into account, the whole energy conversion efficiency is 4.46-6.04%. (author)

Cassava is being considered in Brazil as the main alternative to sugarcane for the production of ethanol for industrial and fuel purposes, and efforts are being made to improve this technology. Among the possible improvements one of the most important is the increase in the saccharification and fermentation yields and productivities when these operators are accomplished simultaneously. In this work, using Saccharomyces cerevisiae, ethanol fermentations from cassava starch were carried out as a function of cell concentration ranging from 0.3 to 15.0 g/l. The main conclusions were that ethanol productivities and yields were not affected by the initial cell concentration unless this was below 0.3 to 0.6 g/l (dry base). Average ethanol productivities of about 4.0%/h were consistently obtained with ethanol yields ranging from 85 to 90%. Concerning reaction rates, it was found that unless very low values of initial cell concentration were used, the saccharification become the limiting step of the overall process.

This work reports the effect of fungal pretreatment of sugarcane straw in the performance of the treated pulps. Fermentation time, fungal mycelium load and pretreatment scale were studied in the fungal treatment, and the best conditions were 15 days with 250mgkg-1 fungal mycelium per straw weight causing high lignin decomposition. At the largest scale tested (50g straw) lignin degradation exceeded cellulose degradation by 2.4-fold. Acetosolv pulping was carried out in a tank reactor at 120degreeC. The pulping kinetics showed that for biopulps the final lignin content was around 7.5% with a reduction of 40% in the pulping time to reach 12.5% pulp lignin, besides the factorial design showed that the biological pretreatment had a positive effect on the acetic acid reduction (21.5wt.%) during ...

Pulps with residual lignin ranging from 6.4-27.4% (w/w) were prepared from mixed softwoods using a proprietary biorefining technology (the Lignol process) based on aqueous ethanol organosolv extraction. The pulps were evaluated for bioconversion using enzymatic hydrolysis of the cellulose fraction to glucose and subsequent fermentation to ethanol. All pulps were readily hydrolyzed without further delignification. More than 90% of the cellulose in low lignin pulps (lignin) was hydrolyzed to glucose in 48 h using an enzyme loading of 20 filter paper units/g cellulose. Cellulose in a high lignin pulp (27.4% residual lignin) was hydrolyzed to >90% conversion within 48 h using 40 filter paper units/g. The pulps performed well in both sequential and simultaneous saccharification and fermentation trials indicating an absence of metabolic inhibitors. Chemical and physical analyses showed that lignin extracted during organosolv pulping of softwood is a suitable feedstock for production of lignin-based adhesives and other products due to its high purity, low molecular weight, and abundance of reactive groups. Additional co-products may be derived from the hemicellulose sugars and furfural recovered from the water-soluble stream. PMID:15772945

Processing of cassava roots by the Alur tribe in Uganda includes a stage of solid substrate fermentation in heaps. Changes in cyanogen levels during the process, microflora involved, and protein levels, amino acid patterns and mycotoxin contamination of the final products were studied. Processing was monitored at six rural households and repeated at laboratory site, comparing it to sun-drying. Flour samples from rural households were analysed for residual cyanogens, mutagenicity, cytotoxicity and aflatoxins. Mean (+/- SD) total cyanogen levels in flours collected at rural households were 20.3 (+/- 16.8) mg CN equivalents kg-1 dry weight in 1990 (n = 23) and 65.7 (+/- 56.7) in 1992 (n = 21). Mean (+/- SD) levels of cyanohydrins plus HCN were 9.1 (+/- 8.7) in the 1992 flours. Total cyanogen levels in the village monitored batches were reduced considerably by heap-fermentation from 436.3 (+/- 140.7) to 20.4 (+/- 14.0) mg CN equivalents kg-1 dry weight cassava. Residual cyanogen levels were positively correlated with particle size of the resulting crumbs. Heap-fermentation was significantly more effective in reducing cyanogen levels than sun-drying alone, but did not always result in innocuous levels of of cyanogens. Dominant mycelial growth was from the fungi Neurospora sitophila, Geotrichum candidum and Rhizopus oryzae. No mutagenicity, cytotoxicity nor aflatoxins could be detected in the flours. Protein quantity and quality were not significantly reduced. Cassava gel viscosity pattern was modified to the consumers' preference by this method. As the removal of cyanogens was more efficient and we found no new obvious health risk, heap-fermentation can be regarded as an improvement compared to sun-drying alone in areas where cassava varieties with higher cyanogen levels prevail, but we recommend optimisation of the process for ensuring still safer products. PMID:7621084

Gari, a staple food consumed in Nigeria, is made from peeled and ground cassava tubers. The ground material is pressed with a stone slab for 2-4 days to remove moisture, and the partially fermented product is then baked over an open fire. Since gari mainly contributes energy to the diet, attempts were made to develop a more nutritious product without altering organoleptic and textural properties. In laboratory tests, ground cassava was fermented in stainless steel cheese vats for 4 days (to produce gari flavour) and then partially dehydrated by pressing in cheese cloth. A reduction in HCN content from 6.2 to 3.4 mg/100 g resulted. Various combinations of spray-dried acid whey, soya protein and freeze-dried Candida tropicalis were added to the fermented cassava, which was then pressure-cooked for 10 minutes at 121 degrees Celcius, dried and ground in a hammer mill. Product (i), made with gari fortified with 15% soya concentrate and 5% dried acid whey, was as acceptable as traditional gari and had a protein score of 75.8 vs. 9.91 for traditional gari. Product (ii), gari fortified with 20% yeast and 10% dried acid whey, had significantly lower scores for flavour and texture than traditional gari and the protein score was only 29.45. Supplementing gari with relatively inexpensive whey concentrates appears to be a means of overcoming protein energy malnutrition in children.

Cassava waste peels may constitute up to 55% of the original tuber. These waste peels were found to contain 41.8% carbohydrate, 1.1% protein, 12.5% ether extract and 4.9%, 4.9% total ash, and 20.8% crude fibre. Studies were conducted to formulate a fermentation medium to convert the waste peels to reducing sugars and to enrich the peels with microbial protein. Amylase-producing microorganisms were isolated from rotten cassava tuber discs buried in the soil at different locations. The microorganisms isolated were Aspergillus fumigatus, A. flavus, A. niger, and a Pseudomonas sp. and A. niger; the level of reducing sugar was 20.5 mg/ml. The lowest was by B. subtilis an isolate from fermenting locust bean. Generally the levels of saccharification were higher when the waste media were supplemented with different nitrogen sourses. The crude protein yield in the cassava peel waste media by different microorganisms varied from 5.6% to 17.5%. The highest protein yield was in the waste medium fermented by A. fumigatus followed by A. niger, B. subtilis, Pseudomonas sp. in decreasing order.

BIOSIS COPYRIGHT: BIOL ABS. Optimal conditions of glucose, ammonium sulphate and mono acid potassium phosphate content in a manipueira-like synthetic medium for submerged fermentation of Trichosporon sp. were determined to be 90 g/l, 10 g/l and 1.0 g/l, respectively. Since manipueira, the main cassava industry waste water, usually has lower contents of carbon, nitrogen and phosphate sources, it is possible to add sugar and salts to reach these improved conditions. As a result it is possible to produce by submerged fermentation around 10 g/l Trichosporon biomass with consumption of approximately 98% from initial sugars in the medium.

Caxiri is a traditional fermented alcoholic beverage produced from cassava and sweet potatoes by the indigenous Juruna or Yudja people in Brazil. Our results showed that caxiri fermentation is invariably associated with the following: (i) an increase in the total microbial population, with yeast being the largest group detected; (ii) a decrease in reducing sugars, malic, tartaric, succinic, oxalic and propionic acid; and (iii) a final product characterised by a high content of ethanol and a high concentration of lactic acid. The microbial community dynamics were investigated by culture-based and culture-independent approaches. Fermentation was assisted by a complex microbial community that changed in structure and composition during the fermentative process. The bacterial population ranged...

The liquefaction, simultaneous saccharification and fermentation (SSF) of cassava starch (225 g/litre glucose equivalent) were investigated in order to optimize the process. It was found that with 0.125% (v/w) alpha-amylase (Termamyl) at 80 degrees C, a one hour liquefaction was sufficient. At 35 degrees C and an optimum AMG concentration of 0.7% (v/w), Zymomonas mobilis ZM4 had a fermentation time of 20 hours, giving 114 g/litre of ethanol (95% of the theoretical yield on starch supplied). Under the same conditions, Saccharomyces uvarum ATCC 26602 had a fermentation time of 33 hours, producing 106 g/litre of ethanol (a 90% yield). The main factors affecting the rate of fermentation with varying AMG concentrations were glucose limitation (at low AMG concentrations) and substrate inhibition (at high AMG concentrations).

Production of virgin coconut oil via natural fermentation has led to large amount of wastes being generated, i.e., coconut pulp and wastewater containing coconut creme. Objective of this study is to gain more insight into the feasibility of utilization of such wastes as raw materials together with several types of wastes such as fish waste and/or pineapple peel for bioextract production. Chemical, physico-chemical and biological changes including phytotoxicity of the fermented mixture were closely monitored. Physical observation suggested that fermentation of bioextract obtained with fish waste appeared to be complete within the first month of fermentation while bioextract obtained using pineapple waste seemed to be complete after 8 months post-fermentation. Fermentation broth is of blacki...

The bulk of the work described here relates to the computer simulation of biomass fermentations in general and to the application of these simulation programs to an existing large-scale fermentation process. The xylose isomerase enzyme from Escherichia coli was purified and its amino acid and gene-sequences determined. The gene was inserted into two yeast strains; the gene produced a protein that resembled xylose isomerase but had no enzymatic activity. In contrast to xylose, hexoses from biomass wastes are routinely fermented to ethanol. The Georgia-Pacific plant in Bellingham, Washington for fermentation of spent liquor from calcium sulfite pulping has an annal capacity of six million gallons of ethanol. A computer model describing this continuous fermentation has been developed. The model is used to test the likely or potential effect of altered fermentation kinetic parameters and plant operating parameters on steady-state process concentrations. The Monod model for cell growth and ethanol production is used (this kinetic model is described in Chapter Four), with appropriate modifications to account for multisubstrate fermentation. Parameters for the Monod kinetic equations are determined using a numerical maximum-likelihood technique to fit experimental data. Steady-state concentrations are calculated by simultaneous solution of the nonlinear differential equations that describe the mass balances for fermentation reactions in each tank. The potential effect of pentose fermentation upon the industrial process is calculated using various estimates of the pentose fermentation behavior that might be achievable in this process, including estimates developed from the fermentation of xylulose.

The pattern of increase in cell number in 12 different groups of bacteria was studied during anaerobic digestion of enzymatically prehydrolysed sugar beet pulp in a 70-1 fermentor with sequential feeding over a period of 130 days. Glucose-fermenting bacteria accounted for 90 % of the total microflor...

The composition of cocoa pulp simulation media (PSM) was optimized with species-specific strains of lactic acid bacteria (PSM-LAB) and acetic acid bacteria (PSM-AAB). Also, laboratory fermentations were carried out in PSM to investigate growth and metabolite production of strains of Lactobacillus pl...

The aldose reductase (AR) inhibitor, 8-hydroxydaidzein, was isolated and identified from a methanolic extract of okara (soybean pulp) fermented with the fungal strain, Aspergillus sp. HK-388. 8-Hydroxydaidzein showed non-competitive inhibition of human recombinant AR with respect to DL-glyceraldehyde, its Ki value being evaluated as 7.0 ?M.   

This research investigated the composting process of cassava pulp and swine manure at various initial C/N ratios of 20/1, 30/1, and 40/1 and the effect of microbial activator, p.d.1, on composting process. Compost with an initial C/N ratio of 30/1 seeded with p.d.1 showed the highest maximum temperature (63.5°C), the lowest number of faecal coliform (2.87 Log10 MPN g-1), and the shortest time (around day 42) to reach maturity, suggesting a suitable initial C/N ratio.   

Abstract in english It has been shown that cassava starch can be converted into alcohol most efficiently when fungal enzyme preparations from submerged cultures are used to hydrolyze the starch into sugar. The use of barley malt in the process for conversion of cassava starch has resulted in alcohol yields of 70-74% of the theoretical. Cassava mashes converted by submerged fungal cultures (Aspergillus niger van Tieghem, strain NRRL-337) resulted in alcohol yields up to 90% of the theoretical (more) . Substitutes for the distillers'dried solubles-corn medium were tried. Screened cotton seed meal and soybean meal proved to be a satisfactory substitute for distillers'dried solubles. Dehydrated cassava meal was effectively used in place of corn meal. A comparative study was carried out using several molds from the Collection of the Instituto Agronômico for the purpose of determining their enzyme activity. The mold that presented the highest enzyme potency was found to be the strain of Aspergillus oryzae (Ahlburg) Cohn strain F-27 which had been originally isolated from saké (rice wine). Studies of the dehydrated residues (7% moisture) from hydrolized and fermented mash were found to contain approximately 25% protein indicating their possible value in animal feeds. Simple substrates can be used for the propagation of the mold which is a very efficient conversion agent. It is, indeed, the best saccharifying agent for the countries where a good malt is not available at a low price.

One near-term option to developing a forest product biorefinery is to derive pre-pulping extract from incoming wood chips before the main pulping step. The release of monomer sugars from a xylan-rich extract, creating a fermentable substrate is a prerequisite for utilization of pre-pulping extract for production of ethanol or other value-added products. This study examined the individual and mixture efficiencies of two hemicellulolytic microbial enzymes and two xylanase preparations in catalyzing degradation of green liquor (GL) and hot water (HW) pre-pulping extracts. The effects of four commercial enzyme preparations were determined by assessing yields of xylose + galactose + mannose (xmg) obtained under different reaction conditions. Of the individual enzyme preparations tested, a sampl...

Guava pulp used for ethanol production by three yeast strains contained 10% (w/v) total sugars and was pH 4.1. Ethanol production at the optimum sugar concentration of 10%, at pH 4.1 and 30{sup o}C was 1.5%, 3.6% and 3.9% (w/v) by Saccharomyces cerevisiae MTCC 1972, Isolate-1 and Isolate-2, respectively, at 60 h fermentation. Higher sugar concentrations at 15 and 20% were inhibitory for ethanol production by all test cultures. The maximum production of ethanol at optimum natural sugar concentration (10%) of guava pulp, was 5.8% (w/v) at pH 5.0 by Isolate-2 over 36 h fermentation, which was only slightly more than the quantity of ethanol produced by Saccharomyces cerevisiae (5.0%) and Isolate-1 (5.3%) over 36 and 60 h fermentation, respectively. (Author)

The Value Prior to Pulping (VPP) project goal was to demonstrate the technical and commercial feasibility of introducing a new value stream into existing pulp and paper mills. Essentially the intent was to transfer the energy content of extracted hemicellulose from electricity and steam generated in the recovery boiler to a liquid transportation fuel. The hemicellulose fraction was extracted prior to pulping, fractionated, or conditioned if necessary, and fermented to ethanol. Commercial adaptation of the process to wood hemicelluloses was a prerequisite for using this less currently valued component available from biomass and wood. These hemicelluloses are predominately glucurono-xylan in hardwoods and galactoglucomannan in softwoods (with a significant softwood component of an arabino-xylan) and will yield fermentation substrates different from cellulose. NREL provided its expertise in the area of fermentation host evaluation using its Zymomonas strains on the CleanTech Partner's (CTP) VPP project. The project was focused on the production of fuel ethanol and acetic acid from hemicellulose streams generated from wood chips of industrially important hardwood and softwood species. NREL was one of four partners whose ethanologen was tested on the hydrolyzed extracts. The use of commercially available enzymes to treat oligomeric sugar extracts was also investigated and coupled with fermentation. Fermentations by NREL were conducted with the Zymomonas mobilis organism with most of the work being performed with the 8b strain. The wood extracts hydrolyzed and/or fermented by NREL were those derived from maple, mixed southern hardwoods, and loblolly pine. An unhydrolyzed variant of the mixed southern hardwood extract possessed a large concentration of oligomeric sugars and enzymatic hydrolysis was performed with a number of enzymes, followed by fermentation. The fermentation of the wood extracts was carried out at bench scale in flasks or small bioreactors, with a maximum volume of 500 mL.

To improve the production of L-lactic acid by Streptococcus bovis using an original medium of fresh cassava roots (FCR) in tofu liquid waste (TLW), three nutrient supplements, skim milk (SM), the residue of the yeast extract waste (YEW) from beer manufacturer and concentrated maguro waste (CMW) from fish manufacturing were independently added to the original medium (FCR-TLW). Maximum fermentation properties (fermented L-lactic acid concentration, productivity of L-lactic acid and specific growth rate) were obtained at about 2% w/w crude protein concentration in the original medium for three nutrient supplements. The highest fermentation properties were shown by CMW supplement, and they were comparable with those in the standard medium. The medium supplemented with 2% w/w crude protein concentration of CMW in the original medium (FCR-TLW-CMW2) clearly gave the greatest effects on L-lactic acid production.   

Thermophilic co-fermentation of cassava stillage (CS) and cassava excess sludge (CES) were investigated for hydrogen and methane production. The highest hydrogen yield (37.1ml/g-total-VS added) was obtained at VSCS/VSCES of 7:1, 17% higher than that with CS digestion alone. The CES recycle enhanced the substrate utilization and improved the buffer capacity. Further increase the CES fraction led to changed VFA distribution and more hydrogen consumption. FISH analysis revealed that both hydrogen producing bacteria and hydrogen consuming bacteria were enriched after CES recycled, and the acetobacteria percentage increased to 12.4% at VSCS/VSCES of 6:2. Relatively high efficient and stable hydrogen production was observed at VSCS/VSCES of 5:3 without pH adjusted and any pretreatment. The highe...

An investigation was carried out to approach the degradation of cyanide and maturity during the cassava processing wastes composting process. Mixtures of cassava hull, cassava residues and pig manure were used in the experiment. Parameters like temperature, pH, cyanide, cellulose, hemicellulose, lignin and C/N ratio were assessed during the composting process, the effect of composting process on the degradation of cyanide and maturity were evaluated. The results reveal that the content of cyanide decreases sharply and declines to 2.08 mg/kg (30 days of composting), the degradation rate of cyanide is 94.16% and is in accord with food safety standard. After 15 days of the composting process, degradation of composting materials containing carbon (starch, cellulose, hemicellulose) and cyanide are quick and the degradation rates of them are more than 80%, properties tend towards stability basically. During 30 days of the composting process, the composting temperature drops to normal temperature and tends to stability, pH remains stable at 7.2. Parameters like C/N ratio, nitrate-nitrogen (NO3(-)-N) and ammonia nitrogen (NH4(+)-N) as maturity evaluation index were measured, and the results indicate that physical and chemical properties keep stability after 15 days of cassava processing wastes composting process. At the end of fermentation, C/N ratio is 17.55, the content of nitrate-nitrogen and ammonia nitrogen reach 2.5g/kg and 10 mg/kg respectively, NO3(-)-N/NH4(+)-N ratio is 250. The changes of these above mentioned parameters meet with maturity evaluation standard. Proving that cassava processing wastes during 30 days of composting treatment can achieve stability and security state. PMID:19558134

The liberation of polysaccharides during an NPE-removing pretreatment of chips prior to kraft pulping has been studied (NPE: non-process elements). In this investigation the amount of polysaccharides, which can be recovered for fermentation to ethanol, has been estimated. The idea was that polysaccharides that are fragmented and dissolved during cooking could be dissolved already in an NPE-removing pretreatment. When wood chips are pretreated at pH 2-3, with the purpose of removing NPEs, some polysaccharides are dissolved. The dissolution is strongly affected by the temperature and a relatively large increase of the polysaccharide dissolution was noted when the pretreatment temperature was raised from 100 to 120 deg C. At the conditions considered proper for an NPE-removing pretreatment (100 deg C), a pulp mill producing 400 000 ADt pulp/year could produce 660 m{sup 3} ethanol (94%)/year, if the hexoses in the recovered polysaccharides were fermented. If also the pentoses were fermented, the production of ethanol could amount to 1520 m{sup 3}/year. An increase in pretreatment temperature to 120 deg C would significantly increase the possible production of ethanol, but probably on the expense of the pulp yield.

Most of the wood pulp in the U.S. is produced by cooking, or digesting, wood chips in a chemical solution. These pulping processes have effluent streams which contain dissolved lignins, lignin breakdown products, and carbohydrates. There is a substantial economic incentive to use these materials as feedstocks for the production of high-valued micellar flood chemicals. The pulp and paper industries have practiced chemical recovery for almost a century. The largest chemical recycle processes are the internal recycle of inorganic salts for reuse in pulping. This is coupled with the use of waste organic compounds in the liquor as a fuel for directly-fired evaporation processes. Diversion of effluent and low valued streams for chemical recovery using fermentation, purification, or synthesis methods appears technically feasible in several cases. The use of new recovery processes could yield a variety of different wood-effluent based products. Some of the sugar acids in pulping liquors might be used as sequestering agents in reservoirs where there are large amounts of multivalent cations in flood brines. Fermentation production of high viscosity polymers, sequestering agents, and coagent alcohols appears worth further investigation. Tall oil acids and their derivatives can be used as surfactants in some reservoirs. Some waste constituents may adsorb preferentially on formations and thereby reduce loss of surfactants and other higher-valued chemicals.

Extraction of hemicellulose from hardwood chips prior to pulping is a possible method for producing ethanol and acetic acid in an integrated forest bio-refinery, adding value to wood components normally relegated to boiler fuel. Hemicellulose was extracted from hardwood chips using green liquor, a pulping liquor intermediate consisting of aqueous NaOH, Na(2)CO(3), and Na(2)S, at 160 degrees C, held for 110 min in a 20 L rocking digester. The extracted liquor contained 3.7% solids and had a pH of 5.6. The organic content of the extracts was mainly xylo-oligosaccharides and acetic acid. Because it was dilute, the hemicellulose extract was concentrated by evaporation in a thin film evaporator. Concentrates from the evaporator reached levels of up to 10% solids. Inhibitors such as acetic acid and sodium were also concentrated by this method, presenting a challenge for the fermentation organisms. Fermentation experiments were conducted with Escherichia coli K011. The un-concentrated extract supported approximately 70% conversion of the initial sugars in 14 h. An extract evaporated down to 6% solids was also fermentable while a 10% solids extract was not initially fermentable. Strain conditioning was later found to enable fermentation at this level of concentration. Alternative processing schemes or inhibitor removal prior to fermentation are necessary to produce ethanol economically. PMID:19944597

Cassava pulp is a major by-product produced in a cassava starch factory, containing 50-60% of starch (dry basis). Therefore, in this study we are considering its potential as a raw material substrate for the production of methane. To ensure sufficient amounts of nutrients for the anaerobic digestion process, the potential of co-digestion of cassava pulp (CP) with pig manure (PM) was further examined. The effect of the co-substrate mixture ratio was carried out in a semi-continuously fed stirred tank reactor (CSTR) operated under mesophilic condition (37 C) and at a constant OLR of 3.5 kg VS m(-3) d(-1) and a HRT of 15 days. The results showed that co-digestion resulted in higher methane production and reduction of volatile solids (VS) but lower buffering capacity. Compared to the digestion of PM alone, the specific methane yield increased 41% higher when co-digested with CP in concentrations up to 60% of the incoming VS. This was probably due to an increase in available easily degradable carbohydrates as the CP ratio in feedstock increased. The highest methane yield and VS removal of 306 mL g(-1) VSadded and 61%, respectively, were achieved with good process stability (VFA:Alkalinity ratio < 0.1) when CP accounted for 60% of the feedstock VS. A further increase of CP of the feedstock led to a decrease in methane yield and solid reductions. This appeared to be caused by an extremely high C:N ratio of the feedstock resulting in a deficiency of ammonium nitrogen for microbial growth and buffering capacity.

Acacia villosa, a thornless shrub legume, has potential as a feed supplement for ruminants if anti-nutritional factors, especially tannins, can be overcome. The effects of chopping and soaking the leaves on the amounts of tannin in the extracting solution and that left in the recovered leaves were studied. The tannin and non-tannin phenolics were solubilized in the extracting solution and the amount was increased with the soaking time. Soaking in calcium hydroxide solution, hydrochloric acid or water removed 41-76% of tannin and total phenolics removed from the recovered leaves. Soaking of the leaves also removed fermentable materials and reduced the gas production. In the first of two digestibility experiments, three groups of goats received one of these diets, those were: (1) sugar cane tops: unsoaked Acacia leaves (7:3), (2) sugar cane tops: water soaked Acacia leaves (7:3) and (3) sugar cane tops: water soaked Acacia leaves (7:3) + 100 g/day of cassava flour. Live weight of goats was measured every 2 weeks and a large increase in average daily gain was obtained for goats fed diet containing water soaked leaves and cassava flour (71 g/day) compared to those fed diet containing unsoaked leaves and water soaked leaves (38.9 and 44.7 g/day, respectively) (P < 0.05). In the second digestibility experiment, the three diets were: (1) sugar cane tops: unsoaked Acacia (7:3), (2) sugar cane tops water soaked Acacia (7:3), (3) sugar cane tops: calcium hydroxide soaked Acacia (7:3). A supplement of 100 g/day of cassava flour was added to each of these three diets. In both digestibility experiments, soaking improved intake and digestibility of Acacia leaves, and cassava flour increased the intake, but when all the diets contained cassava flour, there was no significant difference (P > 0.05) found in intake or digestibility between unsoaked and soaked leaves. In conclusion, soaking reduced tannin in Acacia leaves, improved digestibility and intake of Acacia leaves. In the presence of cassava flour, soaking improved average daily gain. Diets supplemented with water soaked Acacia leaves probably also need an energy supplement and cassava flour is one of the feed ingredients that is satisfactory. (author)

Four early-lactation crossbred cows (82.5 % Holstein) were selected to investigate the effect of carbohydrate source and cottonseed meal level in the concentrate on rumen fermentation and milk production. Cows were randomly assigned to receive four dietary treatments according to a 2?×?2 factorial arrangement in a 4?×?4 Latin Square design. Factor A was carbohydrate source: cassava chip (CC) and CC + rice bran at a ratio 3:1 (CR3:1), and factor B was variation in the level of cottonseed meal (CM): low (LCM) and high (HCM) in isonitrogenous diets (180 g CP/kg DM). It was found that carbohydrate source did not affect feed intake, dry matter digestibility, rumen fermentation, microbial population, milk yield and composition, or economic return (P?>?0.05). However, cows fed with CC had a higher population of amylolytic bacteria than cows fed with CR3:1 (P??0.05). In addition, the carbohydrate source and cottonseed meal level interactions were not significant for any parameter. It could be concluded that cassava chip and high level of cottonseed meal could usefully be incorporated into concentrates for dairy cows without impacting on rumen fermentation or milk production. PMID:22843214

Clostridium acetobutylicum strains used in most Chinese ABE (acetone-butanol-ethanol) plants favorably ferment starchy materials like corn, cassava, etc., rather than sugar materials. This is one major problem of ABE industry in China and significantly limits the exploitation of cheap waste sugar materials. In this work, cane molasses were utilized as substrate in ABE production by Clostridium saccharobutylicum DSM 13864. Under optimum conditions, total solvent of 19.80 g/L (13.40 g/L butanol) was reached after 72 h of fermentation in an Erlenmeyer flask. In a 5-L bioreactor, total solvent of 17.88 g/L was attained after 36 h of fermentation, and the productivity and yield were 0.50 g/L/h and 0.33 g ABE/g sugar consumption, respectively. To further enhance the productivity, a two-stage semicontinuous fermentation process was steadily operated for over 8 days (205 h, 26 cycles) with average productivity (stage II) of 1.05 g/L/h and cell concentration (stage I) of 7.43 OD(660), respectively. The average batch fermentation time (stage I and II) was reduced to 21-25 h with average solvent of 15.27 g/L. This study provides valuable process data for the development of industrial ABE fermentation process using cane molasses as substrate. PMID:22362519

Polylactic acid (PLA) is synthesized by direct polycondensation without catalyst (NC-DP) method using a lactic acid (HLa) solution which had been refined by concentration, esterification and hydrolysis of fermented broth from fresh cassava roots (FCR). Higher polymerization rates and earlier thermal degradation had been observed, compared with those from a pure lactic acid solution. It is due to residual impurities in refining process, such as butanol (BuOH) and butyl lactate (BuLa), which act as an external catalyst. Additionally, it has been found that thermal degradation of PLA containing these impurities occurs via random scission with vinyl end groups, in regard to specific scission for PLA from a pure HLa solution.   

Abstract in portuguese As propriedades das resinas de troca iônica, da Amberlite IRA 402, uma resina de troca aniônica forte, e da IRA 67, uma resina de troca aniônica fraca, foram determinadas para se avaliar a adequabilidade comparativa delas à obtenção de ácido lático de bagaço de mandioca fermentado. Dados sobre a capacidade de ligação e sobre a obtenção provaram que a resina de base fraca na forma de cloreto era a mais adequada para a obtenção de ácido lático em soluções (more) aquosas e meios de fermentação. Os meios de fermentação obtidos da sacarificação e da fermentação simultâneas de meios baseados hidrolisados de fécula de bagaço de mandioca foram usados para o estudo da obtenção de ácido lático usando uma coluna de resina de base fraca. A Amberlite IRA 67 mostrou-se muito mais eficaz do que a Amberlite IRA 402 para a obtenção de ácido lático. Como em outros relatórios, devido à presença de nutrientes e íons que não lactatos, a capacidade de ligação foi ligeiramente inferior enquanto se utilizavam meios fermentados em vez de soluções ácidas láticas aquosas. Abstract in english The properties of the ion exchange resins, Amberlite IRA 402, a strong anion exchange resin and IRA 67, a weak anion exchange resin were determined to evaluate their comparative suitability for lactic acid recovery from fermented cassava bagasse. Data on binding capacities and recovery proved that weak base resin in chloride form was the most favourable ones for lactic acid recovery from aqueous solutions and fermentation media. Fermented media obtained through simultaneo (more) us saccharification and fermentation of cassava bagasse starch hydrolysate based medium were used for lactic acid recovery study using weak base resin column. Amberlite IRA 67 had much more efficiency than Amberlite IRA 402 to recover lactic acid. Like in other reports, due to the presence of nutrients and ions other than lactate, the binding capacity was slightly lesser while using fermented media (~93%) instead of aqueous lactic acid solutions (~98%).

Sugar beet pulp (SBP) is a carbohydrate-rich residue of table sugar processing. It shows promise as a feedstock for fermentable sugar and biofuel production via enzymatic hydrolysis and microbial fermentation. This research focused on the enzymatic hydrolysis of SBP and examined the effects of solid loading (2-10 %, dry basis), enzyme preparation, and enzyme recycle on the production of fermentable sugars. The enzyme partitioning to the solid and liquid phases during SBP enzymatic hydrolysis and loss during recycling were investigated using SDS-PAGE and Zymogram analysis. Without considering product inhibition, the cellulase added initially to the SBP hydrolysis lost only 6 % filter paper activity and negligible carboxymethyl cellulose activity upon multiple cycles of SBP hydrolysis. It was found that enzyme dosage can be reduced by 50 % while maintaining similar, and in some cases higher fermentable sugar yield. The removal of hydrolysis products will further improve enzymatic hydrolysis of SBP for biofuel production. PMID:22580744

An indigenously developed food mixture which contained huskless barley flour, green gram dhal flour, skimmed milk powder and tomato pulp ("BGMT" mixture) was autoclaved, cooled and fermented with L. acidophilus at 37 degrees C for 24 h at a dosage of 100,000 cells/ml. This process markedly reduced the phytic acid and polyphenol content and significantly improved the in vitro digestibility of starch and protein. Starch digestibility almost doubled in the fermented mixture. A significant negative relationship was obtained between the contents of antinutrients and digestibility. PMID:9131698

The potential of sugar beet pulp (SBP) and dried sugar beet pulp (DSBP) as economically cheap and renewable supports for immobilization of Saccharomyces cerevisiae cells was investigated. The hydrated supports showed similar cells retention capacities of 0.178+/-0.038g/g and 0.182+/-0.041g/g for SBP and DSBP, respectively. The DSBP-immobilized biocatalyst was used for repeated ethanol fermentation, because DSBP is more stable material. Yeast cells immobilization was confirmed by the scanning electron microscopy (SEM). Repeated batch ethanol fermentation of thick juice by yeast immobilized on hydrated DSBP was successfully carried out for at least seven successive cycles without any significant decrease in ethanol production, while in the case of molasses, after the third batch, significant...

Green liquor consists of sodium carbonate and sodium sulfide and is readily available in any kraft mills. The green liquor pretreatment process for bioethanol production was developed for wood chips. This process uses only proven technology and equipment currently used in a kraft pulp mill and has several additional advantages such as high sugar recovery and concentration, no inhibitive substances produced, as compared to acid-based pretreatment methods. The liquor was used to pretreat corn stover for enhancing enzymatic hydrolysis in bioethanol production. Pulp yield of 70% with 45% lignin removal was achieved under optimized conditions (8% total titratable alkali, 40% sulfidity and 140°C). About 70% of the original polysaccharides were converted into fermentable sugars, using 20 FPU/g-pulp of enzyme in the subsequent enzymatic hydrolysis. The result indicates that green liquor is a feasible pretreatment to improve the enzymatic saccharification of corn stover for bioethanol production. PMID:22989657

One near-term option to developing a forest product biorefinery is to derive pre-pulping extract from incoming wood chips before the main pulping step. The release of monomer sugars from a xylan-rich extract, creating a fermentable substrate is a prerequisite for utilization of pre-pulping extract for production of ethanol or other value-added products. This study examined the individual and mixture efficiencies of two hemicellulolytic microbial enzymes and two xylanase preparations in catalyzing degradation of green liquor (GL) and hot water (HW) pre-pulping extracts. The effects of four commercial enzyme preparations were determined by assessing yields of xylose + galactose + mannose (xmg) obtained under different reaction conditions. Of the individual enzyme preparations tested, a sample NS 50012 was superior to the other enzyme preparations in releasing xmg under conditions optimized for separate hydrolysis and fermentation and for simultaneous saccharification and fermentation. In comparison to pre-pulping extracts treated with HW, extract treated with GL was found to inhibit the action of all tested enzymes. This inhibition may be related to higher salt and lignin phenol in the GL extract. On both types of extracts, the mixture constituted by NS 50012 and NS 50030 provided the highest yield of hemicellulose conversion at 55 degrees C and pH 5.5. The generated digestibility thus signified that the synergistic effectiveness in xylan + galactan + mannan (XMG) hydrolysis between NS 50012 (from Aspergillus aculeatus) and NS 50030 (from Aspergillus oryzae) is the result of an interaction mechanism involving different XMG-degrading enzyme activities in the two enzyme preparations. PMID:20084471

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

In view of the current industrial process for the conventional ethanol fermentation, in which raw starch materials are heated at 120 degrees C for 2 h, conditions for an alternative process were set: an overall time from saccharification to ethanol fermentation of within 3-4 days, an operation temperature of below 60 degrees C, an ethanol yield of over 93%, and a ratio of raw material to fermentation volume of within 1:4. To meet these conditions, previously a steeping method of starch materials in 0.5N HCl solution at 60 degrees C for 12 h were used, followed by combined actions of ..cap alpha..-amylase and glucoamylase. The ethanol yield from uncooked cassava starch treated under the conditions described was 95% after fermentation for 3 days with Saccharomyces cerevisiae. However, the use of a relatively higher concentration of acid for steeping is still a problem and gelatinization of starch materials is insufficient. This communication, therefore, describes effects of alkali steeping and structural change of starch granules on the ethanol fermentation. 8 references.

To improve the hygienic quality condition of wet `fufu', an indigenous fermented cassava product produced in South-West Nigeria, the processing facilities were upgraded and GMP implemented before HACCP application in processing plants in Abeokuta. The effectiveness of the GMP and HACCP was assessed by monitoring the environment and `fufu' production. Air sampling and swabbing of equipment surfaces revealed a microbiota which was consistent with the fermented product. The results before application of GMP and HACCP showed the predominance of Staphylococcus aureus in the wet `fufu' samples ranging between 1.1x104cfu/g and 2.5x105cfu/g. Monitoring after application showed that the raw materials, products, processing parameters conformed to the critical limits within which the safety of the fo...

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

Abstract in portuguese Goma xantana é um biopolímero comercial produzido por fermentação de glicose e Xanthomonas com larga aplicação industrial. O objetivo deste trabalho foi estudar a síntese e a viscosidade da goma obtida por cepas nativas de Xanthomonas campestris utilizando soro de mandioca como substrato fermentativo alternativo. Três tipos de Xanthomonas foram utilizados. A maior produção foi de 13,83 g.L-1 obtida do meio fermentativo com X. campestris mangiferaeindicae a 25 º (more) C, 250 rpm por 120 horas apresentando uma viscosidade aparente de 96,14 cP na concentração de 2,0% de solução de xantana a 25 s-1, 25 ºC. O uso do resíduo industrial de soro de mandioca para biossíntese da xantana é uma alternativa de baixo custo para o processo fermentativo e um destino para esse soro. Abstract in english Xanthan gum is a commercial biopolymer produced by fermentation of glucose and Xanthomonas with many industrial applications. The objective of this work was to study the synthesis and the viscosity of xanthan obtained from native strains of Xanthomonas campestris using cassava as an alternative fermentative substrate. Three kinds of Xanthomonas were used. The highest production was 13.83 g.L-1 obtained with X. campestris mangiferaeindicae fermented at 25 ºC, 250 rpm duri (more) ng 120 hours and presenting apparent viscosity 96.14 cP in the concentration of 2.0% of xanthan solution at 25 s-1, 25 ºC. The use of the industrial residue of cassava serum for biosynthesis of xanthan is a low cost alternative for the fermentation process and a noble use for this waste.

Production of virgin coconut oil via natural fermentation has led to large amount of wastes being generated, i.e., coconut pulp and wastewater containing coconut crème. Objective of this study is to gain more insight into the feasibility of utilization of such wastes as raw materials together with several types of wastes such as fish waste and/or pineapple peel for bioextract production. Chemical, physico-chemical and biological changes including phytotoxicity of the fermented mixture were closely monitored. Physical observation suggested that fermentation of bioextract obtained with fish waste appeared to be complete within the first month of fermentation while bioextract obtained using pineapple waste seemed to be complete after 8 months post-fermentation. Fermentation broth is of blackish color with alcoholic as well as acidic odour with no gas bubble and/or yeast film present on top of the surface. During the whole fermentation interval, several attributes of both bioextracts, e.g., pH, chemical oxygen demand (COD) and organic acids, were statistically different. Further, the total bacteria and lactic acid bacteria present in pineapple bioextract were statistically higher than those of the fish bioextract (pbioextracts, respectively. In addition, qualities of both bioextracts conformed well with those specified by the Thai standard for liquid biofertilizer after 1 month fermentation. Results further showed that wastewater derived from virgin coconut oil manufacturing process could effectively be employed together with other types of wastes such as fish waste and pineapple peel for bioextract production. However, for the best bioextract quality, fermentation should be carefully planned since over fermentation led to bioextract of low qualities. PMID:20362440

The effect of controlled fermentation processes on the microbial association and biochemical profile of cv. Conservolea naturally black olives processed by the traditional anaerobic method was studied. The different treatments included (a) inoculation with a commercial starter culture of Lactobacillus pentosus, (b) inoculation with a strain of Lactobacillus plantarum isolated from a fermented cassava product and (c) uninoculated spontaneous process. Microbial growth, pH, titratable acidity, organic acids and volatile compounds were monitored throughout the fermentation. The initial microbiota consisted of Gram-negative bacteria, lactic acid bacteria and yeasts. Inhibition of Gram-negative bacteria was evident in all processes. Both starter cultures were effective in establishing an accelerated fermentation process and reduced the survival period of Gram-negative bacteria by 5 days compared with the spontaneous process, minimizing thus the likelihood of spoilage. Higher acidification of the brines was observed in inoculated processes without any significant difference between the two selected starter cultures (113.5 and 117.6mM for L. plantarum and L. pentosus, respectively). L. pentosus was also determined as the major species present during the whole process of spontaneous olive fermentation. It is characteristic that lactic acid fermentation was also initiated rapidly in the spontaneous process, as the conditions of fermentation, mainly the low salt level (6%, w/v) favored the dominance of lactic acid bacteria over yeasts. Lactic, acetic and propionic were the organic acids detected by HPLC in considerable amounts, whereas citric and malic acids were also present at low levels and degraded completely during the processes. Ethanol, methanol, acetaldehyde, ethyl acetate were the major volatile compounds identified by GC. Their concentrations varied among the different treatments, reflecting varying degrees of microbial activity in the brines. The results obtained from this study could help the Greek table olive industry to improve the existing processing schemes in order to increase product consistency and quality expanding the international market for naturally black olives. PMID:18206777

In this study, we illustrated the performance and microbial community of single- and two-phase systems anaerobically co-digesting cassava pulp and pig manure. The results showed that the volatile solid reduction and biogas productivity of two-phase CSTR were 66 ± 4% and 2000 ± 210 ml l-1 d-1, while those of singlephase CSTR were 59 ± 1% and 1670 ± 60 ml l-1 d-1, respectively. Codigestion in two-phase CSTR gave higher 12% solid degradation and 25% methane production than single-phase CSTR. Phylogenetic analysis of 16S rDNA clone library revealed that the Bacteroidetes were the most abundant group, followed by the Clostridia in singlephase CSTR. In hydrolysis/acidification reactor of two-phase system, the bacteria within the phylum Firmicutes, especially Clostridium, Eubacteriaceae and Lactobacillus were the dominant phylogenetic groups. Among the Archaea, Methanosaeta sp. was the exclusive predominant in both digesters while the relative abundance of Methanosaeta sp. and Methanospirillum hungatei differed between the two systems.

Slow pyrolysis studies of palm kernel cake (PKC) and cassava pulp residue (CPR) were conducted in a fixed-bed reactor. Maximum liquid yield (54.3 wt%) was obtained from PKC pyrolysis at 700 °C, heating rate of 20 °C/min, N2 gas flow rate of 200 cm3/min and particle size of 2.03 mm. Fuel properties of bi-oils were in following ranges: density, 1.01?1.16 g/cm3; pH, 2.8?5.6; flash point, 74?110 °C and heating value, 15 MJ/kg for CPR oil and 40 MJ/kg for PKC oil. PKC oil gave main contents of n-C8?C18 carboxylic acids, phenols, and esters, whereas CPR oil gave the highest amount of methanol soluble fraction consisting of polar and non-volatile compounds. On gas compositions, CPR pyrolysis gave the highest yield of syngas produced, while PKC pyrolysis offered the highest content of CO2. Pyrolys...

This selected bibliography includes 250 articles on cassava as a potential energy source. Factors included are things which influence cassava growth; such as weeding, fertilizer, diseases and genetic selection, as well as the conversion of cassava to ethanol. (DP)

Dog diets may differ in their effectiveness of maintaining satiety after a meal. Consequently, sensations of hunger, feeding motivation, physical activity, and sensitivity to environmental stressors may be increased. Dietary fibre may be effective in prolonging postprandial satiety depending on type and inclusion level. This study evaluated the effect of fibre fermentability on behaviour in dogs. Sixteen healthy adult dogs were housed individually and fed a low-fermentable fibre (LFF) diet containing 8.5% cellulose or a high-fermentable fibre (HFF) diet containing 8.5% sugar beet pulp and 2% inulin. Dogs were fed two equal portions at 8:30 and 18:30 according to energy requirements. Behaviour of dogs in their home-cage was recorded and analyzed by instantaneous scan sampling (2x24h with 15...

Abstract in portuguese As indústrias brasileiras de processamento de fécula produzem, como descarte, grandes quantidades de bagaço ou farelo de mandioca que é jogado fora, poluindo o meio ambiente, ou é utilizado na alimentação de animais. A proposta desta pesquisa consiste na utilização do bagaço, descarte da fecularia, como produto para consumo na alimentação humana. Foi preparado, a partir do bagaço coletado na fecularia um produto farináceo identificado como "farinha de mandio (more) ca teste", a qual apresentou, em comparação com as farinhas comerciais, alta quantidade (43,1%) de fibra alimentar e baixa quantidade (47,1%) de amido. Os teores de proteína, lipídeo e cinzas foram semelhantes ao das farinhas comerciais. A "farinha teste" foi usada no preparo de dietas semi-sintéticas para ratos em crescimento nas concentrações de 11,6 , 34,8 e 58,0%; farinhas adquiridas no comércio foram usadas como referência. A freqüência de defecações, o peso das fezes úmidas e secas e o volume das fezes secas foram maiores para os grupos supridos com dietas contendo a "farinha teste", em comparação com os grupos que receberam a farinha do comércio, mas, com relação aos valores dos quocientes de eficiência alimentar (QEA) e protéica (PERop) não houve diferença significativa entre as duas farinhas. Uma redução no ganho de peso corpóreo dos animais, resultante de diminuição da ingestão de alimento, foi observado para os tratamentos contendo a farinha teste. Tais resultados permitiram concluir que a "farinha de mandioca teste" apresentou propriedades fisiológicas, em nível intestinal, características da fibra alimentar insolúvel e, em vista disso, constitui-se numa fonte potencial de fibra para a alimentação humana. O bagaço de mandioca produzido como descarte nas fecularias poderá ser aproveitado como matéria-prima para a produção de uma farinha de mandioca rica em fibra alimentar insolúvel, característica distinta das farinhas de mandioca existentes no comércio. Abstract in english At the brazilian starch industries the production process of sour or fermented cassava starch generates a high quantity of a by-product denominated residual cassava fibrous waste or bagasse. Normally such material is discarded with deleterious effects to the environment or it is utilized, in low quantity, as a component of animal feed. It was prepared in laboratory, from the bagasse, a cassava flour which presented higher insoluble dietary fiber (43.1%) and lower starch ( (more) 47.1%), compared to cassava flours obtained from the market place. The proportions of protein, lipid and ash of the high-fiber flour were similar to commercial flours. In addition, defecation frequency, wet (fresh) and dry fecal weight and fecal bulking in rats fed high-fiber flour increased, but It did not interfere in the food efficiency ratio and on the protein efficiency ratio (PER op) values. A reduction of the body weight gain, as a result of a decrease in food ingestion, was observed for the treatments containing the high fiber cassava flour. Such results indicate that the high-fiber cassava flour presents nutritional and gastrointestinal properties which allows it to be used as an adequate source of dietary fiber for human nutrition. The cassava fibrous waste may be used as high-fiber cassava flour containing high proportion of insoluble fiber, a distinct feature from the regular commercial flour.

The objective of this research was to study the production of biogas by using pineapple pulp and peel, the by-products from fruit processing plants, in a plug-flow reactor (17.5 L total volume). The effects of feed concentration, total solids (TS) and hydraulic retention time (HRT) on degradation of the waste were investigated. The increase of pineapple pulp and peel of 2% (wt/vol) at HRT 7 d to 4% (wt/vol) at HRT 10 d showed increases in biogas production rate, biogas yield and methane yield - from 0.12 v/v-d, 0.26 m(3)/kg COD removed and 0.11 m(3)/kg COD removed, with COD removal at 64.1%, to 0.25 v/v-d, 0.43 m(3)/kg COD removed and 0.14 m(3)/kg COD removed, with COD removal at 60.41%. The methanogenic fermentation was more active in the middle and final parts of the reactor. The recirculation of fermentation effluent at 40% (vol/vol) of the working volume into the reactor could increase the biogas production rate and biogas yield up to 52% and 12%, respectively. The results showed technological potential for waste treatment of pineapple pulp and peel in a plug-flow reactor. PMID:22705859

Wood chips of Pinus radiata softwood were biotreated with the brown rot fungus (BRF) Gloeophyllum trabeum for periods from 4 and 12 weeks. Biodegradation by BRF leads to an increase in cellulose depolymerization with increasing incubation time. As a result, the intrinsic viscosity of holocellulose decreased from 1,487 cm(3)/g in control samples to 783 and 600 cm(3)/g in 4- and 12-week decayed wood chips, respectively. Wood weight and glucan losses varied from 6 to 14% and 9 to 21%, respectively. Undecayed and 4-week decayed wood chips were delignified by alkaline (NaOH solution) or organosolv (ethanol/water) processes to produced cellulosic pulps. For both process, pulp yield was 5-10% lower for decayed samples than for control pulps. However, organosolv bio-pulps presented low residual lignin amount and high glucan retention. Chemical pulps and milled wood from undecayed and 4-week decayed wood chips were pre-saccharified with cellulases for 24 h at 50 degrees C followed by simultaneous saccharification and fermentation (SSF) with the yeast Saccharomyces cerevisiae IR2-9a at 40 degrees C for 96 h for bioethanol production. Considering glucan losses during wood decay and conversion yields from chemical pulping and SSF processes, no gains in ethanol production were obtained from the combination of BRF with alkaline delignification; however, the combination of BRF and organosolv processes resulted in a calculated production of 210 mL ethanol/kg wood or 72% of the maximum theoretically possible from that pretreatment, which was the best result obtained in the present study. PMID:20480204

Abstract in portuguese Em virtude da progressiva substituição dos adjuntos amiláceos pelos xaropes com alta concentração de maltose nas cervejarias brasileiras, o presente trabalho teve por objetivo comparar hidrolisados de milho e de mandioca, como adjunto de malte, na fabricação de cerveja tipo Pilsen, em escala de laboratório. Os hidrolisados foram produzidos a partir de amido de milho e fécula de mandioca, sendo que na liqüefação e sacarificação da fração amilácea destes pr (more) odutos foram utilizadas, respectivamente, as enzimas comerciais Termamil (alfa amilase bacteriana) e Fungamil (alfa amilase fúngica). Na fabricação das cervejas, a proporção de malte e hidrolisado foi de 2 para 1, na base do extrato. O mosto foi produzido pelo processo de infusão e após resfriamento e clarificação foi inoculado com levedura cervejeira de baixa fermentação. A fermentação transcorreu a 10 °C até 90% de atenuação do extrato aparente fermentável. As cervejas foram engarrafadas e, em seguida, maturadas a 0 °C, por 14 dias. Terminado o processo de fabricação, as cervejas foram analisadas química e sensorialmente. A semelhança na composição química dos hidrolisados de milho e de mandioca refletiu na composição química dos mostos e das cervejas. Não houve diferença estatística entre os mostos e entre as cervejas testadas para todos os parâmetros químicos analisados. Também, não existiu diferença sensorial entre as cervejas produzidas com hidrolisado de milho e hidrolisado de mandioca. Concluiu-se que a fécula de mandioca apresenta potencial de uso como matéria prima para a fabricação de xarope de maltose de uso cervejeiro e que há elevada probabilidade de sucesso no uso desse xarope para a fabricação de cervejas. Abstract in english The brazilians breweries replace progressively starchy adjuncts by sugary liquid adjuncts made with maize. Thus, the objective of present work was saccharify cassava and maize and use them as malt adjunct on Pilsen beer production, in laboratory scale. The syrups (35 °Brix) were produced with cassava and maize starch by utilisation of Termamil and Fungamil commercial enzymes. The beers were made using malt and syrups in proportion of 2: 1, on extract basis. The wort was (more) produced by infusion process, after cooling and clarification it was inoculated with lager yeast. The fermentation temperature was 10°C and the fermentative process was finished with 90% of attenuation. After that, the beers were bottled and lagered at 0°C by 14 days. The beers were chemically and sensorially analysed. The similarity of chemical composition of cassava and maize syrups reflected on the chemical composition of worts and beers. The chemical analysis showed there was not statistical difference between wort produced with cassava syrup and wort made with maize syrups. As well, the chemical analysis showed beers made with these adjuncts did not present statistical difference. The sensory analysis realised by triangular test, showed beer made with cassava syrup and beer produced with maize syrup were equal. It was concluded that cassava starch presents potential utilisation as raw material for brew maltose syrup production.

The wastes materials from the sweet orange (Citrus sinensis) were used as substrate for the production of cellulase. The rind, the pericarp or albedo and the pulp were hydrolyzed by cellulolytic enzymes of Trichoderma longibrachiatum, Aspergillus niger and Saccharomyces cerevisiae after they were treated with alkali and steam. The amount of glucose released from the substrates following the secretion of cellulase by the three microorganisms was measured. The orange wastes released amounts of glucose ranging from 0.76-0.96 mg mL(-1) by Trichoderma longibrachiatum, 0.90-1.08 mg mL(-1) by A. niger and 0.60-0.76 mg mL(-1) by S. cerevisiae after five days of fermentation. The conditions of the fermentation were then varied to determine their effect on cellulase production. Fermentation parameters varied were time, pH, substrate concentration, temperature and inoculum size. After this, conditions that produced highest amounts of glucose were combined in an optimization experiment. Glucose production under optimized conditions were 0.94 mg mL(-1) by T. longibrachiatum, 0.83 mg mL(-1) by A. niger and 0.67 mg mL(-1) by S. cerevisae. The activity of the test organisms' cellulase against CMC on the orange wastes was also determined with T. longibrachiatum producing 3.86 mg mL(-1), A. niger 2.94 mg mL(-1) and S. cerevisiae 2.30 mg mL(-1) glucose amounts all from orange pulp. PMID:19137846

Green liquor consists of sodium carbonate and sodium sulfide and is readily available in any kraft mills. The green liquor pretreatment process for bioethanol production was developed for wood chips. This process uses only proven technology and equipment currently used in a kraft pulp mill and has several additional advantages such as high sugar recovery and concentration, no inhibitive substances produced, as compared to acid-based pretreatment methods. The liquor was used to pretreat corn stover for enhancing enzymatic hydrolysis in bioethanol production. Pulp yield of 70% with 45% lignin removal was achieved under optimized conditions (8% total titratable alkali, 40% sulfidity and 140degreeC). About 70% of the original polysaccharides were converted into fermentable sugars, using 20 FPU...

During tree growth, hardwoods can initiate the formation of tension wood, which is a strongly stressed wood on the upper side of the stem and branches. In Eucalyptus globulus, tension wood presents wider and thicker cell walls with low lignin, similar glucan and high xylan content, as compared to opposite wood. In this work, tension and opposite wood of E. globulus trees were separated and evaluated for the production of bioethanol using ethanol/water delignification as pretreatment followed by simultaneous saccharification and fermentation (SSF). Low residual lignin and high glucan retention was obtained in organosolv pulps of tension wood as compared to pulps from opposite wood at the same H-factor of reaction. The faster delignification was associated with the low lignin content in tens...

Concentrated acid hydrolysis of cellulosic material results in high dissolution yields. In this study, the neutralization step of concentrated acid hydrolysate of conifer pulp was optimized. Dry conifer pulp hydrolysis with 55 % H(2)SO(4) at 45 °C for 2 h resulted in total sugar yields of 22.3-26.2 g/L. The neutralization step was optimized for solid Ca(OH)(2), liquid Ca(OH)(2) or solid CaO, mixing time, and water supplementation. The highest hydrogen yield of 1.75 mol?H(2)/mol glucose was obtained with liquid Ca(OH)(2), while the use of solid Ca(OH)(2) or CaO inhibited hydrogen fermentation. Liquid Ca(OH)(2) removed sulfate to below 30 mg SO(4) (2-)/L. Further optimization of the neutralization conditions resulted in the yield of 2.26 mol?H(2)/mol glucose. PMID:23065404

Abstract in spanish La mora de Castilla (Rubus glaucus Benth) es una fruta de interés comercial y altamente perecedera, que presenta deterioro debido a su fragilidad e inadecuado manejo poscosecha, cantidades apreciables de fruta son afectadas, básicamente en sus características físicas, siendo este producto apto para el procesamiento industrial. Veinte kg de mora fueron despulpados, homogenizados y caracterizada la pulpa, determinando; grados brix de 6,0; porcentaje de acidez de 2,91 % (more) y densidad de 0,991 g/ml en promedio. Se formularon licores, con una participación de la pulpa del 25 %, 30 %, 35 %, 40 %, 45 %, 50 % y 55 % iniciando con 35 °Brix, para todos los casos en el mosto fermentable, ajustando las formulaciones con sacarosa; la levadura inoculada fue Saccharomyces cerevisiae Meyen ex E.C. Hansen en concentración del 0,2 %; la fermentación se llevó a cabo en reactores con capacidad de 2 litros, con desfogue de manguera de látex, el mosto fermentable fue dejado en los reactores durante 20 semanas, luego los licores fueron filtrados y caracterizados físico-químicamente, evaluando el porcentaje de alcohol por destilación, encontrando que el porcentaje de 40 % de participación de pulpa, fue el de mayor concentración con 8,36 % de volumen de alcohol en promedio. Los resultados estadísticos mostraron una diferencia significativa entre los porcentajes de participación de pulpa y su influencia sobre la producción de alcohol para los valores de 25 % y 30 % con respecto a los porcentajes 35 %, 40 %, 45 %, 50 % y 55 %. Un modelo matemático lineal apropiado para la producción de alcohol en función de la participación de pulpa fue obtenido. La prueba sensorial con 10 jueces, mostró que el licor preparado con 35 % de participación de pulpa, fue el de mayor aceptación. Abstract in english The blackberry (Rubus glaucus Benth) is a fruit of commercial interest that is highly perishable, showing appreciable damage due to fragileness and inadequate pos-harvesting handling. Large quantities of fruits are affected in their physical characteristics principally, with this product adequate for industrial processing. Twenty kg of blackberry were converted to pulp and homogenized and the pulp was characterized, encountering: grades of brix of 6,0; percent acidity of (more) 2,91 % and density of 0,991 g/ml on average. Liquors were prepared with blackberry pulp in the following compositions: 25 %, 30 %, 35 %, 40 %, 45 %, 50 %, and 55 %, beginning with 35 °Brix for all cases in the fermentable must, adjusting the formulations with sucrose; the added yeast was Saccharomyces cerevisiae Meyen ex E.C. Hansen in a concentration of 0,2%; the fermentation was conducted in 2 liter capacity tanks with latex tube vents, the fermentable must remained in the tanks for 20 weeks, later the liquors were filtered and characterized chemically and physically, evaluating the alcohol percentage for distillation, documenting that the 40% blackberry pulp liquors produced the highest concentration of 8,36% of alcohol volume, on average. The statistical results showed a significant difference among the percent participation of pulp and its influence on the production of alcohol for levels of 25 % and 30 % with respect to levels of 35 %, 40 %, 45 %, 50 % and 55 %. A mathematical lineal model appropriate for the production of alcohol as a function of the participation of pulp was obtained. The sensory test with 10 judges indicated that the liquor prepared with 35 % pulp was the most accepted.

The first stage of chocolate production consists of a natural, seven-day microbial fermentation of the pectinaceous pulp surrounding beans of the tree Theobroma cacao. There is a microbial succession of a wide range of yeasts, lactic-acid, and acetic-acid bacteria during which high temperatures of up to 50 degrees C and microbial products, such as ethanol, lactic acid, and acetic acid, kill the beans and cause production of flavor precursors. Over-fermentation leads to a rise in bacilli and filamentous fungi that can cause off-flavors. The physiological roles of the predominant micro-organisms are now reasonably well understood and the crucial importance of a well-ordered microbial succession in cocoa aroma has been established. It has been possible to use a synthetic microbial cocktail inoculum of just 5 species, including members of the 3 principal groups, to mimic the natural fermentation process and yield good quality chocolate. Reduction of the amount of pectin by physical or mechanical means can also lead to an improved fermentation in reduced time and the juice can be used as a high-value byproduct. To improve the quality of the processed beans, more research is needed on pectinase production by yeasts, better depulping, fermenter design, and the use of starter cultures. PMID:15462126

One of the major problems for cassava is the rapid deterioration after harvesting cassava tuberous roots, which limits the possibilities for production and distribution of cassava in the world. Postharvest deterioration is an inherent problem for cassava since wounding and mechanical damage of the t...

Abstract in portuguese O objetivo deste estudo foi avaliar o consumo e a digestibilidade aparente total (DAT) e parcial dos nutrientes das silagens de cana-de-açúcar (SCnPc), de raspa (SRpPc) e de casca de mandioca (SCcPc) ensiladas com polpa cítrica peletizada (PCP). A dieta basal foi constituída de silagem de milho com farelo de soja, participando com 60% da matéria seca (MS) dos tratamentos com SRpPc e SCcPc. Foram utilizados novilhos mestiços, fistulados no rúmen e duodeno, num delin (more) eamento experimental em quadrado latino (4x4). A determinação do coeficiente de digestibilidade total e parcial dos nutrientes, a produção fecal e o fluxo duodenal de MS foram estimados a partir da fibra detergente ácido indigestível. Os consumos de MS e proteína bruta (PB) (% PV) foram superiores para a SMi (2,47 e 0,33), SCcPc (2,12 e 0,30) e SRpPc (1,88 e 0,27) em relação à SCnPc (1,38 e 0,19), respectivamente. As DAT da matéria seca (65,0%), matéria orgânica (66,9%) e energia bruta (64,3%) para a SRpPc foram superiores em relação às demais dietas, menos para a FDN (39,4%). Os coeficientes de digestibilidade ruminal (CDR) e intestinal (CDI) da MS, MO e PB não apresentaram diferenças significativas entre as dietas, somente o CDR da FDN (% ingerido) apresentou valores superiores para SMi (43,5), SRpPc (39,3) e SCnPc (37,0), sobre a SCcPc (20,0). A utilização da silagem de raspa de mandioca adicionada da PCP mostrou-se uma alternativa de boa qualidade na alimentação de bovinos. Abstract in english The goal of this study was to evaluate the intake of nutrients and the total and partial apparent digestibility of sugar cane + citrus pulp (ScSCp), cassava hulls + citrus pulp (ChSCp) and cassava root + citrus pulp (CrSCp) silages. The basal diet with corn silage (CS) and soybean meal composed 60% of the total dry matter of ChSCp and CrSCp treatments. Four castrated crossbred (HxZ) steers were, canulated in the rumen and in the duodenum and confined according to 4x4 Lati (more) n Square design. For total and partial digestibility of nutrients determination, the dry matter (DM) fecal output and duodenal flow, were estimated by neutral detergent fiber. The DM and crude protein (CP) intake (%LW) of CS (2.47 and 0.33), ChSCp (2.12 and 0.30) and CrSCp (1.88 and 0.27) were higher than ScSCp (1.38 and 0.19). The dry matter (65.0%), organic matter (66.9%), and the gross energy (64.3%) total apparent digestibilities were higher than the other diets, with the exception for NDF (39.4%). The DM, OM and CP ruminal (RDC) and intestinal (IDC) digestibility coefficients, as percentage of intake, did not show significant differences among the diets. The RDC of the NDF to diets: CS (43.4%), the CrSCp (39.3%), and the ScSCp (37.0%) were higher than ChSCp (20.0%). The cassava meal + citrus pulp silage utilization showed to be a good alternative for bovine feeding.

Abstract in spanish Para evaluar los tipos de fermentadores usados por los productores de Cumboto, fueron cosechadas, desgranadas y fermentadas en sacos de yute, cajas de plástico y de madera saqui saqui, mazorcas de cacao tipo forastero de la zona. El proceso fermentativo tuvo una duración de cuatro días y los granos fueron volteados a las 24 y 72 horas de iniciado el proceso. La temperatura fue medida diariamente, así como los índices de hinchamiento y fermentación a los 0, 2 y 4 d, (more) tiempo en el que también fueron determinados la humedad, proteínas, pH, acidez total, taninos y azúcares totales en la pulpa + testa y en el cotiledón del grano en fermentación. Los resultados revelaron que entre los fermentadores, las características físicas no variaron significativamente, en cambio las características químicas difirieron a un nivel de probabilidad del 5%, lo que influyó sobre la humedad, los taninos, la acidez y los azúcares de la pulpa + testa y sobre la humedad y las proteínas del cotiledón. Los tres tipos de fermentadores resultaron eficientes en el proceso fermentativo, ya que se alcanzaron temperaturas e índices de fermentación apropiados, sin embargo por las características químicas obtenidas en el cacao y por razones de uso práctico, del manejo, el cajón de madera pudiese ser considerado como el tipo de fermentador más adecuado. Abstract in english To evaluate the fermentation devices used by cocoa producers in Cumboto, cocoa pods of the foreign type were collected, threshed and fermented in sacks of yute, and in plastic and saqui saqui wood boxes. The fermentative process lasted for four days and the mass was turned at 24 and 72 hours past the initiation of the process. The temperature was measured daily and swelling index and cut test were measured at 0, 2 and 4 days after the process began, at the same time, mois (more) ture, proteins, pH, total acidity, tannins and total sugars in pulp + testa and cotyledon of fermentation grains were also determined. The results revealed that physical properties didn't vary significantly; on the other hand, chemical characteristics differed, to a level of probability of 5%, between fermentation devices, which had an effect in moisture, tannins, total acidity and total sugars of pulp + testa, and in moisture and proteins of cotyledon. The three types of fermentation devices efficiently favored the fermentative process, since the appropriate temperatures and fermentation indexes were reached, however because of the chemical characteristics obtained in the cocoa and for reasons of practical use, as for handling, the wooden box could be considered as the most adequate device.

For an agricultural, oil-importing country such as Costa Rica, the use of biomass as a source of transportation fuels is a topic of great interest. This analysis is intended to assist the Costa Rican government and USAID/CR to identify possible biomass energy projects. While emphasis is on technologies for converting biomass into liquid fuels, agronomic issues and alternative energy options are also explored. Costa Rica plans to build six facilities for converting biomass (primarily sugarcane, supplemented by molasses, cassava, and banana wastes) to hydrous ethanol. The following issues relating to biomass conversion technologies are identified: use of hydroelectrically powered drives in sugarcane processing to allow use of bagasse as a fuel; possible sources and costs of energy for converting starch crops like cassava to ethanol; the optimal method for treating stillage; and the feasibility of using fermentation reactors. No definitive recommendation on the scale of ethanol production is made due to the lack of an environmental impact assessment. Finally, with regard to nonalcohol renewable energy, several ideas warrant consideration: electrically powered mass transit; electric cars; vehicle-mounted gasifiers operating on wood chips or pelletized fuels produced from excess bagasse; anaerobic digestion of animal manure and other agricultural wastes; and energy recovery from municipal solid wastes.

Thermophilic co-fermentation of cassava stillage (CS) and cassava excess sludge (CES) were investigated for hydrogen and methane production. The highest hydrogen yield (37.1 ml/g-total-VS added) was obtained at VS(CS)/VS(CES) of 7:1, 17% higher than that with CS digestion alone. The CES recycle enhanced the substrate utilization and improved the buffer capacity. Further increase the CES fraction led to changed VFA distribution and more hydrogen consumption. FISH analysis revealed that both hydrogen producing bacteria and hydrogen consuming bacteria were enriched after CES recycled, and the acetobacteria percentage increased to 12.4% at VS(CS)/VS(CES) of 6:2. Relatively high efficient and stable hydrogen production was observed at VS(CS)/VS(CES) of 5:3 without pH adjusted and any pretreatment. The highest total energy yield, the highest COD and VS degradation were obtained at VS(CS)/VS(CES) of 7:1. GFC analysis indicated that the hydrolysis behavior was significantly improved by CES recycle at both hydrogen and methane production phase. PMID:22789828

Rhodotorula mucilaginosa TJY15a which was isolated from surface of marine fish could accumulate a large amount of lipid from hydrolysate of cassava starch. The cells contained 47.9% (w/w) oil during batch cultivation, whereas 52.9% (w/w) of lipid was obtained during the fed-batch cultivation. At the end of the fed-batch cultivation, all the starch were converted into reducing sugar and only 0.34 g dm{sup -3} of reducing sugar was left in the fermented medium. Therefore, the marine-derived R. mucilaginosa TJY15a was another candidate for single cell oil production. The fatty acids from R. mucilaginosa TJY15a were mainly composed of palmitic acid (C{sub 16:0}), palmitoleic acid (C{sub 16:1}), stearic acid (C{sub 18:0}), oleic acid (C{sub 18:1}) and linolenic acid (C{sub 18:2}), suggesting that the fatty acids could be used as feedstock for biodiesel production. (author)

Aspergillus awamori possesses the ability to digest raw starches. For the effective utilization of starchy crops in South-Asian countries, it is important to digest raw starches without cooking for the industrial fermentation process. In this study, mutant strains of Aspergillus awamori IFO4033 with increased activity of ?-amylase were isolated from freeze dried spores irradiated with C5+ ion-beams. The frequency of the mutation and the activity were higher for C5+-irradiated samples than those for gamma-irradiated ones. Compared to the digestibility of raw starches from cassava, sago and sukun by the parent strain, it increased two- to threefold by some mutant strains obtained from C5+ ion-beam irradiated spores.   

The purpose of the study was to evaluate the sensory profile and acceptability of six types of fufu (a fermented cassava product) produced by different processes using sensory evaluation and consumer acceptability testing. Fufu samples were selected to evaluate the acceptability of dried fufu flours, which are increasingly being consumed, and compare with a traditional paste and a newly developed paste that produces less environmental waste. Descriptive sensory profiles of the selected samples demonstrated distinct differences in sensory profiles. They were evaluated for consumer acceptance at three demographic locations; Lagos (n = 91), Ibadan (n = 121) and Abeokuta (n = 99), Nigeria. Fufu made from a paste that produced less environmental waste had the highest acceptance scores, followed...

In a previous work, a continuous simultaneous saccharification and fermentation process to produce ethanol from cassava starch was studied, using a set of fixed-bed reactors. The biocatalyst consisted of glucoamylase immobilized in silica particles and co-immobilized with S. cerevisiae in pectin gel. Using 3.8?U mL?1 reactor and 0.05?gwet yeast mL?1 reactor at start-up, starch hydrolysis was the rate-limiting step. Maximum ethanol productivity was 5.8?gethanol L?1 h?1, with 94.0% conversion of total reducing sugars (TRS) and 83.0% of the ethanol theoretical yield. In this work, the molar mass of the substrate and the biocatalyst particle size were reduced in an attempt to improve the bioreactor performance. The diameters of silica and pectin gel particles were reduced from 100??m and 3?4?m...

Ethanol tolerance is a key trait of microbes in bioethanol production. Previous studies have shown that soya flour contributed to the increase of ethanol tolerance of yeast cells. In this paper, the mechanism of this ethanol tolerance improvement was investigated in cassava ethanol fermentation supplemented with soya flour or defatted soya flour, respectively. Experiment results showed that ethanol tolerance of cells from soya flour supplemented medium increased by 4?6% (v/v) than the control with defatted soya flour. Microscopic observation found that soya flour can retain the cell shape while dramatic elongations of cells were observed with the defatted soya flour supplemented medium. Unsaturated fatty acids (UFAs) compositions of cell membrane were analyzed and the UFAs amounts increase...

In the Caribbean the main root crops produced are cassava, sweet-potatoes, eddoes, dasheen and yam. The production of ethanol from these starchy substrates first requires the hydrolysis of the starch into simpler sugars. Hydrolysis can be performed enzymatically or by means of acids. The root crops selected for study were sweet-potatoes (Ipomoea batatas) and eddoes (Colocasia antiquorum esculenta var. globulifera). They were hydrolysed using the enzymes contained in malt. The sugars obtained under the above conditions were 5.6 and 5.4% (w/v) for sweet-potatoes and eddoes, respectively. The corresponding starch conversions were 88 and 92%. Fermentation of the above hydrolysates gave alcohol in the region of 2.3 and 2.2% (v/v) for sweet-potatoes and eddoes, respectively. The conversion of sugar to alcohol was 91 and 89%. (author).

An extracellular alpha-amylase produced by a cassava-fermenting strain of Micrococcus luteus was purified 26-fold by gel filtration and ion-exchange chromatography. The molar mass was estimated to be approximately 56 kDa. The optimum temperature of the enzyme was 30 degrees C, optimum pH 6.0 and optimum substrate concentration was 0.6% (W/V). Treatment of the enzyme at 70 degrees C for 10 min resulted in 70% loss of activity. The activation energy was determined to be 34.8 kJ/mol. The activity of the enzyme was enhanced by Mg2+, Ca2+, K+, Na+ and inhibited by EDTA, KCN and citric acid. The enzyme may find some application in local food processing. PMID:9438346

The efficient fermentation of mixed substrates is essential for the microbial conversion of second-generation feedstocks, including pectin-rich waste streams such as citrus peel and sugar beet pulp. Galacturonic acid is a major constituent of hydrolysates of these pectin-rich materials. The yeast Saccharomyces cerevisiae, the main producer of bioethanol, cannot use this sugar acid. The impact of galacturonic acid on alcoholic fermentation by S. cerevisiae was investigated with anaerobic batch cultures grown on mixtures of glucose and galactose at various galacturonic acid concentrations and on a mixture of glucose, xylose, and arabinose. In cultures grown at pH 5.0, which is well above the pK(a) value of galacturonic acid (3.51), the addition of 10 g · liter(-1) galacturonic acid did not affect galactose fermentation kinetics and growth. In cultures grown at pH 3.5, the addition of 10 g · liter(-1) galacturonic acid did not significantly affect glucose consumption. However, at this lower pH, galacturonic acid completely inhibited growth on galactose and reduced galactose consumption rates by 87%. Additionally, it was shown that galacturonic acid strongly inhibits the fermentation of xylose and arabinose by the engineered pentose-fermenting S. cerevisiae strain IMS0010. The data indicate that inhibition occurs when nondissociated galacturonic acid is present extracellularly and corroborate the hypothesis that a combination of a decreased substrate uptake rate due to competitive inhibition on Gal2p, an increased energy requirement to maintain cellular homeostasis, and/or an accumulation of galacturonic acid 1-phosphate contributes to the inhibition. The role of galacturonic acid as an inhibitor of sugar fermentation should be considered in the design of yeast fermentation processes based on pectin-rich feedstocks. PMID:22582063

A process for removing inhibitors from pre-hydrolysis liquor (PHL) of a kraft-based dissolving pulp production process by adsorption and flocculation, and the characteristics of this process were studied. In this process, industrially produced PHL was treated with unmodified and oxidized activated carbon as an absorbent and polydiallyldimethylammonium chloride (PDADMAC) as a flocculant. The overall removal of lignin and furfural in the developed process was 83.3% and 100%, respectively, while that of hemicelluloses was 32.7%. These results confirmed that the developed process can remove inhibitors from PHL prior to producing value-added products, e.g. ethanol and xylitol via fermentation.

Tropical countries, such as Brazil and Colombia, have the possibility of using agricultural lands for growing biomass to produce bio-fuels such as biodiesel and ethanol. This study applies an energy analysis to the production process of anhydrous ethanol obtained from the hydrolysis of starch and cellulosic and hemicellulosic material present in the banana fruit and its residual biomass. Four different production routes were analyzed: acid hydrolysis of amylaceous material (banana pulp and banana fruit) and enzymatic hydrolysis of lignocellulosic material (flower stalk and banana skin). The analysis considered banana plant cultivation, feedstock transport, hydrolysis, fermentation, distillation, dehydration, residue treatment and utility plant. The best indexes were obtained for amylaceous...

Pre-extraction–kraft studies of hardwoods showed that when extracting about 10% of the wood, the final kraft pulp yield and physical properties could only be maintained at a level similar to that of regular kraft pulp when the final extract pH was close to neutral. This so-called “near neutral” pre-extraction condition at a level of 10% wood dissolution was achieved by contacting the wood chips with green liquor (GL) at a charge of about 3% (as Na2O on wood) at 160 °C for almost 2 hours (or an H-factor of about 800 hrs.). During subsequent kraft cooking of the pre-extracted hardwood chips the effective alkali charge could be reduced by about 3% (as Na2O on wood) and the cooking time shortened relative to that during regular kraft cooking, while still producing the same bleachable grade kappa number as the kraft control pulp. For softwood, no extraction conditions were discovered in the present investigation whereby both the final kraft pulp yield and physical properties could be maintained at a level similar to that of regular softwood kraft pulp. Therefore for hardwoods the “near- neutral green liquor pre-extraction conditions do meet the requirements of the IFPR concept, while for softwood, no extraction conditions were discovered which do meet these requirements. Application of simulated industrial GL at an extraction H-factor of about 800 hrs and 3% GL charge in a recirculating digester produced an hardwood extract containing about 4% (on wood) of total anhydro-sugars, 2% of acetic acid, and 1.3% of lignin. Xylan comprised of 80% of the sugars of which about 85% is oligomeric. Since only polymeric hemicelluloses and lignin may be adsorbed on pulp (produced at a yield of about 50% from the original wood), the maximum theoretical yield increase due to adsorption may be estimated as 10% on pulp (or 5% on wood). However, direct application of raw GL hardwood extract for hemicelluloses adsorption onto hardwood kraft pulp led to a yield increase of only about 1% (on pulp). By using the wet-end retention aid guar gum during the adsorption process at a charge of 0.5% on pulp the yield gain may be increased to about 5%. Unfortunately, most of this yield increase is lost during subsequent alkaline treatments in the pulp bleach plant. It was found that by performing the adsorption at alkaline conditions the adsorption loss during alkaline treatment in the bleach plant is mostly avoided. Thus a permanent adsorption yield of about 3 and 1.5% (on pulp) was obtained with addition of guar gum at a charge of 0.5 and 0.1% respectively during adsorption of GL hardwood extract on pre-extracted kraft pulp at optimal conditions of pH 11.5, 90 C for 60 minutes at 5% consistency. The beatability of the adsorbed kraft pulps was improved. Also, significant physical strength improvements were achieved. Further study is needed to determine whether the improvements in pulp yield and paper properties make this an economic IFPR concept. Application of the wood solids of a hot water extract of Acer rubrum wood strands as a substitute for polystyrene used for production of SMC maintained the water adsorption properties of the final product. Further work on the physical properties of the hemicellulose containing SMCs need to be completed to determine the potential of wood extracts for the production of partially renewable SMCs. The discovery of the “near-neutral” green liquor extraction process for hardwood was formed the basis for a commercial Integrated Biorefinery that will extract hemicelluloses from wood chips to make biofuels and other specialty chemicals. The pulp production process will be maintained as is proposed in the present researched IFBR concept. This Integrated Biorefinery will be constructed by Red Shield Acquisition LLC (RSA) at the Old Town kraft pulp mill in Maine. RSA in collaboration with the University of Maine will develop and commercialize the hemicellulose extraction process, the conversion of the hemicellulose sugars into butanol by fermentation, and the separation of specialty chemicals such as acetic acid from the extract. When operating the facility will produce 1.5 million gallons per year of butanol and create 16 new “green collar” jobs. Previously, a spare pulp digester was converted to a new extractor, and in 2009 it was demonstrated that a good hemicellulose extract could be produced, while simultaneously producing market pulp. Since then more than 250 hours of operational experience has been acquired by the mill generating a hemicellulose extract while simultaneously producing market pulp at a scale of 1000 tonnes (OD)/day of mixed northern hardwood chips.

Normal butanol, a potential diesel fuel additive, can be produced by the fermentation of paper pulp waste streams by Clostridia with isopropanol, acetone, and ethanol produced as byproducts. To design a distillation process for the recovery of n-butanol from fermentation broth, the vapor-liquid equilibria for the multicomponent system isopropanol-acetone-ethanol-n-butanol-water were modeled using Wilson equations to predict liquid activity coefficients. An extra parameter was added to the Wilson correlation to allow for the partial miscibility between butanol and water. The accuracy of the model was tested by comparing the predicted vapor composition with experimentally obtained values in the immiscible region. Even with the extra parameter, the model did not predict a miscibility gap between n-butanol and water, and the vapor-liquid equilibria were predicted with an accuracy of +- 0.15 mol fraction.

An in vitro gas production technique, where equine faeces was the source of microbial inoculum, was used to determine the effect of particle size (ground vs. unground) on the in vitro fermentation of high-temperature dried lucerne (L) and molassed sugar beet pulp (SB). Two experiments were conducted; in experiment 1, unprocessed (U) L and SB or ground L and SB (G; to pass through a 1mm dry mesh screen) were mixed in the following ratios: 100:0, 90:10, 80:20 and 70:30, L and SB, respectively. In experiment 2, unprocessed L or ground L, and ground SB were mixed in the following ratios: 100:0, 80:20, 60:40, 40:60, 20:80 and 0:100, L and SB, respectively. Substrate combinations were fermented in vitro with equine faecal inocula using in vitro gas production (GP). In both experiments, total gas...

Bioethanol can be obtained from wood by simultaneous enzymatic saccharification and fermentation step (SSF). However, for enzymatic process to be effective, a pretreatment is needed to break the wood structure and to remove lignin to expose the carbohydrates components. Evaluation of these processes requires characterization of the materials generated in the different stages. The traditional analytical methods of wood, pretreated materials (pulps), monosaccharides in the hydrolyzated pulps, and ethanol involve laborious and destructive methodologies. This, together with the high cost of enzymes and the possibility to obtain low ethanol yields from some pulps, makes it suitable to have rapid, nondestructive, less expensive, and quantitative methods to monitoring the processes to obtain ethanol from wood. In this work, infrared spectroscopy (IR) accompanied with multivariate analysis is used to characterize chemically organosolv pretreated Eucalyptus globulus pulps (glucans, lignin, and hemicellulosic sugars), as well as to predict the ethanol yield after a SSF process. Mid (4,000-400 cm(-1)) and near-infrared (12,500-4,000 cm(-1)) spectra of pulps were used in order to obtain calibration models through of partial least squares regression (PLS). The obtained multivariate models were validated by cross validation and by external validation. Mid-infrared (mid-IR)/NIR PLS models to quantify ethanol concentration were also compared with a mathematical approach to predict ethanol yield estimated from the chemical composition of the pulps determined by wet chemical methods (discrete chemical data). Results show the high ability of the infrared spectra in both regions, mid-IR and NIR, to calibrate and predict the ethanol yield and the chemical components of pulps, with low values of standard calibration and validation errors (root mean square error of calibration, root mean square error of validation (RMSEV), and root mean square error of prediction), high correlation between predicted and measured by the reference methods values (R (2) between 0.789 and 0.997), and adequate values of the ratio between the standard deviation of the reference methods and the standard errors of infrared PLS models relative performance determinant (RPD) (greater than 3 for majority of the models). Use of IR for ethanol quantification showed similar and even better results to the obtained with the discrete chemical data, especially in the case of mid-IR models, where ethanol concentration can be estimated with a RMSEV equal to 1.9 g?L(-1). These results could facilitate the analysis of high number of samples required in the evaluation and optimization of the processes. PMID:23070712

ABSTRACT The processing and acceptability of fried cassava balls ("Akara-akpu") supplemented with melon and soybean flours were studied. Cassava flour, defatted soybean flour and cassava mash were produced. Some functional and chemical properties of the flours were determined. Akara-akpu prepared from 100% cassava mash served as control; 100% cassava flour, 80% cassava flour + 20% defatted soybean and 70% cassava flour + 30% defatted melon flour were prepared. Akara-akpu balls were subjected to chemical and physical analyses. Akara-akpu prepared from composite flour blends had higher protein, fat, ash and energy value than Akara-akpu from 100% cassava mash. The cyanide content and degree of starch gelatinization of Akara-akpu prepared from 100% cassava mash (control) were higher than Akara...

Abstract in portuguese O mamão é fruta perecível, de vida útil pós-colheita curta. Novas tecnologias de conservação de produtos hortícolas com possibilidade de emprego em sistemas orgânicos têm sido desenvolvidas, a exemplo dos revestimentos comestíveis, que podem ser consumidos com o produto. Neste trabalho avaliou-se o amadurecimento de frutos de mamão Formosa 'Tainung 1' em temperatura ambiente, revestidos com película comestível à base de fécula de mandioca, que foi aplicada (more) por meio de imersão dos frutos durante um minuto em suspensões de 1%, 2% e 3%. No dia da aplicação do tratamento e a cada quatro dias, durante 12 dias, os frutos foram avaliados quanto à perda de massa, cor da casca, firmeza da polpa, sólidos solúveis (SS), acidez titulável (AT) e relação SS/AT. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial 4 x 4 (% de fécula na suspensão de tratamento x dias após o tratamento), com quatro repetições e um fruto por parcela. Os revestimentos comestíveis à base de fécula de mandioca a 1% e 3% prolongaram a vida útil pós-colheita de frutos de mamão Formosa 'Tainung 1' por quatro dias, sem afetarem a qualidade dos mesmos. Estes tratamentos retardaram o amadurecimento dos frutos, cujas alterações de cor da casca, firmeza da polpa, SS e AT foram significativamente mais lentas que os frutos não tratados. Abstract in english Papaya is a perishable fruit, of short shelf-life. New technologies of conservation of horticultural products with the possibility of being used in organic systems have been developed, such as the edible coatings that can be eaten with the product. In this work it was evaluated 'Tainung 1' Formosa type papaya ripening at room temperature and coated with edible cassava starch , which was applied by dipping the fruits during one minute in suspensions of 1%, 2% and 3%. In th (more) e day of treatment application and every four days, during 12 days, fruits were evaluated for mass loss, skin color, pulp firmness, total soluble solids (SS), total titratable acidity (AT) and ratio (SS/AT). The experiment was conducted at a completely randomized design, in a 4 x 4 factorial scheme (% starch in suspension x days after treatment), with four replications and one fruit per plot. The edible coatings of cassava starch at 1% and 3% extended the postharvest life of Formosa 'Tainung 1' papaya fruits for four days, without affecting their quality. These treatments delayed fruit ripening , whose skin color, pulp firmness, SS and AT changes were significantly slower than the ones of non-treated fruits.

Microwave irradiation (MWI) was used as pretreatment of wheat bran and eucalyptus kraft pulp to examine its effect on xylanase production by Bacillus halodurans FNP 135 using solid state fermentation and biobleaching with xylanase, respectively. Irradiation of wheat bran under optimized conditions (600 W, 6 min, and 20 % consistency) resulted in 56.8, and 31.7 % increase in xylanase yield and water absorbance of wheat bran and 17.3 % reduction in reducing sugars content. Optimized MWI of kraft pulp at 850 W, 2 min, and 20 % consistency led to 0.9 % increase in brightness, 10 % decrease in kappa number, 7.7 % increase in water absorbance, 4.6 % decrease in tear factor, 0.9 % increase in burst factor, and 7.5 % increase in viscosity. Also, MWI enhanced xylanase-mediated biobleaching by increasing brightness (1.1 %) and decreasing kappa number (14.3 %) and leading to a total of about 20 % reduction in chlorine consumption. MWI is an economical, efficient, and environment-friendly pretreatment of wheat bran and pulp for enhanced enzyme yield and rapid heating, respectively. PMID:22528655

Enzymatic modification of pulp is receiving increasing interest for energy reduction at the refining step of the paper-making process. In this study, the production of a multi-fiber modifying enzyme from Mamillisphaeria sp. BCC8893 was optimized in submerged fermentation using a response-surface methodology. Maximal production was obtained in a complex medium comprising wheat bran, soybean, and rice bran supplemented with yeast extract at pH 6.0 and a harvest time of 7 d, resulting in 9.2 IU/mL of carboxymethyl cellulase (CMCase), 14.9 IU/mL of filter paper activity (FPase), and 242.7 IU/mL of xylanase. Treatment of old corrugated container pulp at 0.2–0.3 IU of CMCase/g of pulp led to reductions in refining energy of 8.5–14.8%. The major physical properties were retained, including tensile and compression strength. Proteomic analysis showed that the enzyme was a complex composite of endo-glucanases, cellobiohydrolases, beta-1,4-xylanases, and beta-glucanases belonging to various glycosyl hydrolase families, suggestive of cooperative enzyme action in fiber modification, providing the basis for refining efficiency.   

Abstract in portuguese O elevado teor de ácido ascórbico no camu-camu (Myrciaria dubia McVaugh, Myrtaceae) desperta o interesse de extrativistas, agricultores e consumidores, e leva à necessidade de desenvolvimento de tecnologias adequadas para produção em terra firme e aproveitamento industrial do fruto. Este trabalho teve por objetivo verificar a adequação do camu-camu para a produção de bebida alcoólica fermentada, assim como o efeito do branqueamento do fruto e da incorporação d (more) a casca à polpa nas características nutricionais e sensoriais da bebida. Os frutos foram separados em quatro lotes, sendo dois branqueados (90 ºC por 7 min). Após a despolpa, as cascas de um lote de cada tratamento (com e sem branqueamento) foram incorporadas às respectivas polpas e avaliadas quanto à composição química (umidade, pH, acidez, sólidos solúveis, açúcares, ácido ascórbico, compostos fenólicos, antocianinas e flavonóides). Após a correção do mosto com açúcar, pasteurização, fermentação (25 dias), trasfega, pasteurização (70 ºC por 15 min), filtragem e clarificação, as bebidas foram avaliadas quanto a composição química, edulcoradas e submetidas à análise sensorial. O branqueamento reduziu a concentração de ácido ascórbico das polpas (33 %) e a agregação da casca aumentou os teores de matéria seca (39 % polpa), ácido ascórbico (33 % na polpa, 23 % no mosto e 50 % na bebida) e fenólicos (50 % bebida). O perfil sensorial e a aceitabilidade sugerem que o camu-camu é adequado para a produção de bebida alcoólica fermentada e que a agregação da casca à polpa contribuiu positivamente para a aceitabilidade (6,7 com casca e 6,2 sem casca, na escala de 9 pontos). As bebidas apresentaram flavor característico do fruto, limpidez, coloração vermelho-laranjada e sabor agradável. Abstract in english The high levels of ascorbic acid in camu-camu (Myrciaria dubia McVaugh, Myrtaceae) have stimulated interest of extractivists, farmers and consumers. This has led to a need to develop adequate technology for it's production on non-flooded land and the industrial use of this fruit. This study had as its main objective to verify if camu-camu is adequate for the production of fermented alcoholic beverages, measuring the effect of blanching the fruit and the incorporation of t (more) he fruit peel with the fruit pulp on the nutritional and sensory characteristics of the drink. The fruits were separated into 4 groups, two being blanched (90 ºC for 7 minutes). After the pulp was removed, the peels of one group from each blanching treatment were incorporated into the respective pulps and their chemical composition evaluated. After sugar correction of the must, pasteurisation, fermentation (25 days), decanting, pasteurisation (70 ºC for 15 minutes), filtering and clarification, the beverages were evaluated as to their chemical composition, sweetened and submitted to sensory analysis. Blanching reduced the concentration of ascorbic acid in the pulps (33 %) and the addition of the peel increased the amount of dry matter (39 % in pulp), ascorbic acid (33 % in pulp, 23 % in must and 50 % in drink) and phenolic compounds (50 % in drink). The sensory profile and acceptability suggest that camu-camu is adequate for the production of fermented alcoholic beverages and that the addition of the peel to the pulp contributes positively to it's acceptability (6.7 with versus 6.2 without, of 9 points possible). The beverage had flavour characteristic of the fruit, a orangish-red color and agreeable taste.

Four, rumen fistulated crossbred (Brahman × native) beef cattle steers were randomly assigned to receive four dietary treatments according to a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. Factor A was carbohydrate source; cassava chip (CC) or CC + rice bran at a ratio 3:1 (CR3:1) and Factor B was cotton seed meal level (CM); and 109 g CP/kg (LCM) and 328 g CP/kg (HCM) at similar overall CP levels (490 g CP/kg). The animals were fed 5 g concentrate/kg BW, and urea-treated rice straw (UTS) (50 g urea/kg DM) was fed ad libitum. Carbohydrate source did not affect feed intake, nutrient digestibility, blood urea nitrogen, rumen fermentation, or microbial protein synthesis; however, animals fed with CC had a higher population of total viable bacteria than the CR3:1 treatment (Pruminal pH was higher than the LCM fed treatment (Pcattle diets resulted in lower microbial protein synthesis when compared with the LCM fed treatment (Pcattle. It is also noted that a high level of cotton seed meal in the concentrate may impact rumen fermentation and animal performance. PMID:22072076

Keywords: Farmer perception, indigenous knowledge, extensive cassava, earthworm casts, arbuscular mycorrhiza, crop rotation, nutrient uptake, soil fertility, co-research, land tenure.Farmers in the transitional zone of Benin claim that extensive cassava cropping and prior cotton fertiliser enhance y...

During cassava starch production, large amounts of cyanoglycosides were released and hydrolysed by plant-borne enzymes, leading to cyanide concentrations in the wastewater as high as 200 mg/l. For anaerobic degradation of the cyanide during pre-acidification or single-step methane fermentation, anaerobic cultures were enriched from soil residues of cassava roots and sewage sludge. In a pre-acidification reactor this culture was able to remove up to 4 g potassium cyanide/l of wastewater at a hydraulic retention time (tHR) of 4 days, equivalent to a maximal cyanide space loading of 400 mg CN- 1(-1) day-1. The residual cyanide concentration was 0.2-0.5 mg/l. Concentrated cell suspensions of the mixed culture formed ammonia and formate in almost equimolar amounts from cyanide. Little formamide was generated by chemical decay. A concentration of up to 100 mmol ammonia/l had no inhibitory effect on cyanide degradation. The optimal pH for cyanide degradation was 6-7.5, the optimal temperature 25-37 degrees C. At a pH of 5 or lower, cyanide accumulated in the reactor and pre-acidification failed. The minimal tHR for continuous cyanide removal was 1.5 days. The enriched mixed culture was also able to degrade cyanide in purely mineralic wastewater from metal deburring, either in a pre-acidification reactor with a two-step process or in a one-step methanogenic reactor. It was necessary to supplement the wastewater with a carbon source (e.g. starch) to keep the population active enough to cope with any possible inhibiting effect of cyanide. PMID:9802225

In a method for obtaining cassava flour from cassava roots the following steps are carried out: grating the cassava roots, adding water to the grated matter to form a slurry, removing undesired components, such as proteins, among other components, from the slurry so as to obtain a product mass and, ...

Cassava (Manihot esuculenta) is a major food staple for over 600 million people in Africa, Asia, and Latin America. Major losses in yield result from biotic and abiotic stresses that include diseases such as Cassava Mosaic Disease (CMD) and Cassava Bacterial Blight (CBB), drought, and acid soils. A...

Uniplex and multiplex reverse transcription-polymerase chain reaction (RT-PCR) protocols were developed for the detection of cassava brown streak viruses (CBSVs) in single and mixed infections with cassava mosaic begomoviruses (CMBs) in a tropical crop plant, cassava (Manihot esculenta). CMBs contain ssDNA as their genome (genus Begomovirus, family Geminiviridae) while CBSVs are made up of positive sense ssRNA (genus Ipomovirus, family Potyviridae), and they cause the economically important cassava mosaic and cassava brown streak diseases, respectively, in sub-Saharan Africa. Diagnostic methodologies have long been available for CMBs but they are limited for CBSVs especially in mixed infections. In this study, the two CBSVs, Cassava brown streak virus (CBSV) and Cassava brown streak Uganda virus (CBSUV) occurring singly or in mixed infection with CMBs, African cassava mosaic virus and East African cassava mosaic virus were detected in a single RT-PCR using both previously described and newly designed virus-specific primers. These protocols were highly efficient for detecting CBSVs compared to the existing methods and have great potential to minimize sample handling and contamination. As well as improving the diagnosis of cassava viruses, the development of multiplex RT-PCR protocols have revealed the common occurrence of mixed infections by CBSV and CBSUV in cassava fields of Tanzania and Kenya, which was contrary to the common belief until recently that these two viruses have existed separately. These protocols have implications for diagnosis and epidemiological studies on cassava virus diseases in Eastern Africa. PMID:22080852

Some low-yield sulfite pulping operations ferment spent sulfite liquor (SSL) to remove biochemical oxygen demand associated with dissolved sugars while at the same time generating ethanol as a salable product. Simultaneous saccharification and fermentation (SSF) of primary clarifier sludge in a medium of SSL was proposed as a means of reducing the amount of sludge to be disposed of while at the same time increasing ethanol productivity. In this article, the option of fortifying existing SSL fermenting processes with the sugars produced via in situ enzymatic hydrolysis of sulfite primary clarifier sludge (PCS) has been explored. In 100% SSL PCS hydrolysis rates as high as 3.4 g/(L{center_dot}h) were observed at an initial enzyme loading of 10 filter paper units (FPU)/g PCS. To reduce the deleterious effects of glucose inhibition, single-stage SSF was carried out using cellulose enzymes and Saccharomyces cerevisiae. The production rate of ethanol in SSL was increased by as much as 25% through the SSF process. 12 refs., 4 figs., 2 tabs.

Palm kernel cake (PKC), the residue obtained after extraction of palm oil from oil palm seeds and tamarind seed powder (TSP) obtained after removing the fruit pulp from tamarind fruit pod were tested for the production of tannase under solid-state fermentation (SSF) using Aspergillus niger ATCC 16620. The fungal strain was grown on the substrates without any pretreatment. In PKC medium, a maximum enzyme yield of 13.03 IU/g dry substrate (gds) was obtained when SSF was carried out at 30 degrees C, 53.5% initial substrate moisture, 33 x 10(9) spores/5 g substrate inoculum size and 5% tannic acid as additional carbon source after 96 h of fermentation. In TSP medium, maximum tannase yield of 6.44 IU/gds was obtained at 30 degrees C, 65.75% initial substrate moisture, 11 x 10(9) spores/5 g substrate inoculum, 1% glycerol as additional carbon source and 1% potassium nitrate as additional nitrogen source after 120 h of fermentation. Results from the study are promising for the economic utilization and value addition of these important agro residues, which are abundantly available in many tropical and subtropical countries. PMID:15734308

Abstract in portuguese Objetivou-se com esta pesquisa avaliar os efeitos da idade de corte do capim-elefante cv. Napier (Pennisetum purpureum Schum.) e da inclusão da polpa sobre a qualidade fermentativa e a estabilidade aeróbia da silagem, além de elaborar um índice de recomendação da inclusão de polpa cítrica, em função do teor de umidade do capim, para reduzir os custos com esta tecnologia. Foram confeccionados silos de laboratório (capacidade de 6 litros) e testados 20 tratamento (more) s (quatro repetições), correspondentes a cinco idades de crescimento do capim (40, 60, 80, 100 ou 120 dias após corte de nivelamento) e quatro níveis de inclusão de polpa cítrica peletizada (0, 3, 6 ou 9%, com base na matéria natural do capim), em arranjo fatorial 5 x 4. Houve efeito da interação idade de corte × nível de polpa sobre as concentrações de ácidos acético, propiônico, butírico e lático, a relação lático/acético, o pH, o nitrogênio amoniacal e a temperatura máxima, mas não para a concentração de álcool, a digestibilidade in vitro da MS, o tempo para atingir a temperatura máxima, a taxa para elevação da temperatura e o tempo para elevação da temperatura em 2ºC. A inclusão de polpa melhorou o perfil fermentativo das silagens, com efeito mais pronunciado em silagens produzidas com capins mais novos. Com base no teor de ácido acético e em derivações da equação de superfície gerada, foi possível obter a recomendação de inclusão de 0,7% de polpa cítrica (com base na matéria natural do capim) para cada unidade percentual de MS que o capim possuir abaixo de 32. Portanto, o nível ótimo de inclusão de polpa que otimiza a qualidade da silagem é igual a (32 - MS) x 0,7. Abstract in english The objectives of this trial were to evaluate the effects of regrowth age of elephantgrass (Pennisetum purpureum Schum. cv. Napier), and citrus pulp addition on the fermentation pattern and aerobic stability of their silage. In addition to that, this research also aimed to create a recommendation index of citrus pulp addition taking into account the moisture concentration of the grass, in order to decrease costs of technology adoption. Laboratory silos (6 L-capacity each) (more) were used and 20 treatments were tested, corresponding to 5 different grass regrowth ages (40, 60, 80, 100, or 120 days after harvesting) and four levels of citrus pulp pellets (0, 3, 6, or 9%, based on grass fresh matter) in a factorial arrangement 5 x 4, with four replicates. Regrowth age and citrus pulp addition level interacted for acetic, propionic, butyric, and lactic acid concentrations, lactic/acetic acid ratio, pH, ammoniacal nitrogen, and maximum temperature, but did not for alcohol concentration, in vitro DM digestibility, time to achieve the maximum temperature, rate for increasing temperature, and time for increasing temperature in 2ºC. In general, the addition of citrus pulp improved fermentation pattern of silages, with greater effect when silages were produced with high moisture grasses. Based on acetic acid concentration and using derivations from the surface equation, it was possible to recommend the addition of 0.7% of citrus pulp (based on grass fresh matter) for each percentage unit of grass DM lower than 32%. Therefore, the optimum addition level of citrus pulp which optimizes silage quality is equal to (32 - DM) x 0.7.

Abstract in portuguese Com frutos de pupunha (Bactris gasipaes Kunth) e fermentação natural, índios na Amazônia produzem uma bebida alcoólica turva, densa, com resíduos de polpa, denominada de "caiçuma". Pesquisas realizadas no Instituto Nacional de Pesquisas da Amazônia mostram que com hidrólise enzimática do amido, fermentação por Saccharomyces cerevisiae e filtração adequada, a limpidez e características desejáveis podem ser obtidas. Este experimento teve por objetivo aumenta (more) r o rendimento em bebida e facilitar o processo pelo aumento da proporção água:polpa no mosto e exclusão da hidrólise enzimática do amido, respectivamente. A composição química da polpa dos frutos in natura e cozidos foi determinada, e com a polpa cozida e autoclavada foi preparado o mosto completando-se a quantidade de substrato com a adição de xarope de sacarose. Após a inoculação com Saccharomyces cerevisiae a fermentação foi monitorada diariamente por sete dias através de análises químicas. A bebida foi caracterizada quanto à composição química, edulcorada e analisada sensorialmente. A cocção e autoclavagem ocasionaram hidrólise parcial do amido presente na polpa. A evolução da fermentação foi mostrada pelo consumo de açúcares e produção de ácidos e álcool. O rendimento em bebida (± 60%), graduação alcoólica de 12,1% (v/v), atraente coloração alaranjada clara, limpidez, sabor e aroma agradáveis e boa aceitabilidade (81,90%), mostraram a viabilidade técnica do processo na utilização da pupunha para produção de bebida. O aumento da proporção água:polpa no mosto contribuiu para o rendimento. A exclusão da hidrólise enzimática e o aumento do rendimento em bebida não interferiram na graduação alcoólica, coloração, sabor, aroma e aceitabilidade da bebida alcoólica fermentada de pupunha. Abstract in english Pejibaye (Bactris gasipaes Kunth) fruits and natural fermentation are used by Amazonian natives to produce a thick drink called "caiçuma". The beverage presents high turbidity because of numerous pulp fragments of various sizes. A study done at the National Institute of Amazon Research showed that enzymatic starch hydrolysis, fermentation by Saccharomyces cerevisiae and filtration transformed "caiçuma" into a highly acceptable drink. The experiment was carried out with (more) the aim of increasing beverage volume yield and process efficiency by increasing the water:pulp ratio of the mash and eliminating the starch enzymatic hydrolysis, respectively. Raw and cooked pejibaye fruits were characterized in terms of their chemical properties. The mash was prepared with pejibaye pulp (previously cooked and autoclaved) and sucrose syrup. After Saccharomyces cerevisiae inoculation, the fermentation process was monitored (every 24 hours) during seven days by physical-chemical analysis. The beverage obtained was analyzed chemically, and, after sweetening, was submitted to a sensory evaluation panel. The cooked and autoclaved fruits presented partially hydrolyzed starch. Fermentation evolution was followed by sugar consumption, and alcohol and acid production. The beverage obtained showed high yield (about 60%), ideal alcoholic content (12.1%, v/v), characteristic color of the fruit, clearness, pleasant flavor and high acceptability (81.9%). The fermentation process without enzymatic hydrolysis of pejibaye starch and increased beverage volume did not affect the good quality and acceptability of the pejibaye beverage. The increased water:pulp ratio of the mash formulation contributed to the high beverage yield.

Bagasse and wheat straw were soda-pulped in a digester at 200 degrees under N pressure of up to 13.8 MPa, followed by explosive discharge through nozzles to give pulp having lower yield and higher initial freeness than batch soda pulp. Explosion pulping required less NaOH than conventional batch soda pulping, and the properties of explosion pulp obtained were similar to those of batch soda pulp at a given freeness.

Paper mill sludge is a solid waste material composed of pulp residues and ash generated from pulping and paper making processes. The carbohydrate portion of the sludge has chemical and physical characteristics similar to pulp. Because of its high carbohydrate content and well-dispersed structure, the sludges can be biologically converted to value-added products without pretreatment. In this study, two different types of paper mill sludges, primary sludge and recycle sludge, were evaluated as a feedstock for bioconversion to ethanol. The sludges were first subjected to enzymatic conversion to sugars by commercial cellulase enzymes. The enzymatic conversion was inefficient because of interference by ash in the sludges with the enzymatic reaction. The main cause was that the pH level is dictated by CaCO3 in ash, which is two units higher than the pH optimum of cellulase. To alleviate this problem, simultaneous saccharification and cofermentation (SSCF) using cellulase (Spezyme CP) and recombinant Escherichia coli (ATCC-55124), and simultaneous saccharification and fermentation (SSF) using cellulase and Saccharomyces cerevisiae (ATCC-200062) were applied to the sludges without any pretreatment. Ethanol yields of 75-81% of the theoretical maximum were obtained from the SSCF on the basis of total carbohydrates. The yield from the SSF was also found to be in the range of 74-80% on the basis of glucan. The SSCF and SSF proceeded under stable condition with the pH staying near 5.0, close to the optimum for cellulase. Decrease of pH occurred due to carbonic acid and other organic acids formed during fermentation. The ash was partially neutralized by the acids produced from the SSCF and SSF and acted as a buffer to stabilize the pH during fermentation. When the SSF and SSCF were operated in fed-batch mode, the ethanol concentration in the broth increased from 25.5 and 32.6 g/L (single feed) to 45 and 42 g/L, respectively. The ethanol concentration was limited by the tolerance of the microorganism in the case of SSCF. The ethanol yield in fed-batch operation decreased to 68% for SSCF and 70% for SSF. The high-solids condition in the bioreactor appears to create adverse effects on the cellulase reaction. PMID:20099047

Abstract in portuguese O presente trabalho avaliou a utilização de farelo de trigo e polidextrose como fontes de fibra no enriquecimento de biscoitos de polvilho. Utilizou-se a Metodologia de Superfície de Resposta para verificar a influência da adição destes ingredientes nos parâmetros de qualidade dos biscoitos. As respostas avaliadas do planejamento experimental fatorial completo 2² foram o volume específico, a dureza instrumental, a umidade e a cor - parâmetros L, a* e b*. Para as (more) respostas: volume específico e dureza instrumental, todos os fatores foram significativos, a 95% de confiança, com R² = 0,9307 e 0,8091, respectivamente. Pela análise das superfícies geradas, pode-se observar que o farelo de trigo e a polidextrose reduziram o volume específico e o farelo teve maior efeito no aumento da dureza. A substituição de polvilho azedo por farelo de trigo e polidextrose nas proporções de 1,5 e 5%, respectivamente, gerou uma amostra rica em fibras, com 6,23% de fibra alimentar (calculado teoricamente), sem prejuízo considerável para as características de expansão e dureza, e com boa aceitação sensorial. Abstract in english This work evaluated the use of wheat bran and polidextrose as fiber sources to enrich fermented cassava starch biscuits. The Response Surface Methodology was used to verify the influence of the addition of these fiber sources on the quality parameters of the biscuits. The responses of the 2² central composite rotational experimental design that were evaluated were specific volume, hardness, and moisture and color - parameters L, a*, and b*. For the specific volume and ha (more) rdness responses, all factors were significant: 95% confidence level, with R² of 0.9307 and 0.8091, respectively. Analyzing the surfaces obtained it could be observed that the wheat bran and polidextrose reduced the specific volume and the wheat bran had a greater effect in increasing hardness. The substitution of fermented cassava starch by wheat bran and polidextrose in proportions of 1.5 and 5%, respectively, produced a fiber-rich sample with 6.23% dietary fiber (calculated theoretically) without affecting the expansion and texture characteristics negatively and with a good sensory acceptance.

Insect pests and plant diseases reduce cassava yields substantially, posing a threat to food security throughout the developing world. While agricultural scientists have recognized these threats, few assessments of the geographic distribution of cassava pests and diseases have been made at the global scale. The goal of this study is to make such an evaluation for four key biotic constraints to cassava production in developing countries: whiteflies, cassava green mites, cassava mosaic disease and cassava brown streak disease. Occurrence records were obtained from laboratory and biodiversity databases and from the scientific literature. These records were then used in ecological niche models to predict the potential distribution of cassava pests and diseases. The distribution maps were cross...

The cyanogen content of 35 cassava-based foods was determined using the enzyme-dipstick method. The analyses showed presence of residual cyanogens in these products, and they ranged from 2 to 88 mg HCN equivalent/kg. Foodstuff prepared from grated cassava roots exhibited a lower level of cyanogen content (2-31 mg HCN equivalent/kg) compared with those prepared as cassava root slices or from cassava flour (28-88 mg HCN equivalent/kg). These results showed that current commercial processing methods did not remove all the cyanogen present from cassava roots and it might be worthwhile re-examining these processing practices. In this respect, the report showed that an overnight treatment of cassava root slices with linamarase and cellulase might facilitate the removal of cyanogens. This study also demonstrated the usefulness of enzyme-dipsticks for assessing cyanogen content in cassava food products. PMID:11397512

The intestinal mucosa is constantly exposed to a variety of microbial species including commensals and pathogens, the latter leaving the host susceptible to infection. Antimicrobial peptides (AMP) are an important part of the first line of defense at mucosal surfaces. Human ?-defensins (HBD) are AMP expressed by colonic epithelial cells, which act as broad spectrum antimicrobials. This study explored the direct and indirect effects of green kiwifruit (KF) on human ?-defensin 1 and 2 (HBD-1 and 2) production by epithelial cells. In vitro digestion of KF pulp consisted of a simulated gastric and duodenal digestion, followed by colonic microbial fermentation using nine human faecal donors. Fermenta from individual donors was sterile filtered and independently added to epithelial cells prior to analysis of HBD protein production. KF products obtained from the gastric and duodenal digestion had no effect on the production of HBD-1 or 2 by epithelial cells, demonstrating that KF does not contain substances that directly modulate defensin production. However, when the digested KF products were further subjected to in vitro colonic fermentation, the fermentation products significantly up-regulated HBD-1 and 2 production by the same epithelial cells. We propose that this effect was predominantly mediated by the presence of short-chain fatty acids (SCFA) in the fermenta. Exposure of cells to purified SCFA confirmed this and HBD-1 and 2 production was up-regulated with acetate, propionate and butyrate. In conclusion, in vitro colonic fermentation of green kiwifruit digest appears to prime defense mechanisms in gut cells by enhancing the production of antimicrobial defensins. PMID:22872469

The possibility to utilize fiber sludge, waste fibers from pulp mills and lignocellulose-based biorefineries, for combined production of liquid biofuel and biocatalysts was investigated. Without pretreatment, fiber sludge was hydrolyzed enzymatically to monosaccharides, mainly glucose and xylose. In the first of two sequential fermentation steps, the fiber sludge hydrolysate was fermented to cellulosic ethanol with the yeast Saccharomyces cerevisiae. Although the final ethanol yields were similar, the ethanol productivity after 9.5 h was 3.3 g/l/h for the fiber sludge hydrolysate compared with only 2.2 g/l/h for a reference fermentation with similar sugar content. In the second fermentation step, the spent fiber sludge hydrolysate (the stillage obtained after distillation) was used as growth medium for recombinant Aspergillus niger expressing the xylanase-encoding Trichoderma reesei (Hypocrea jecorina) xyn2 gene. The xylanase activity obtained with the spent fiber sludge hydrolysate (8,500 nkat/ml) was higher than that obtained in a standard medium with similar monosaccharide content (1,400 nkat/ml). Analyses based on deglycosylation with N-glycosidase F suggest that the main part of the recombinant xylanase was unglycosylated and had molecular mass of 20.7 kDa, while a minor part had N-linked glycosylation and molecular mass of 23.6 kDa. Chemical analyses of the growth medium showed that important carbon sources in the spent fiber sludge hydrolysate included xylose, small aliphatic acids, and oligosaccharides. The results show the potential of converting waste fiber sludge to liquid biofuel and enzymes as coproducts in lignocellulose-based biorefineries. PMID:20824487

The optimization of cultural variables resulted in a marked enhancement in the secretion of cellulase-free and alkali-thermostable xylanase (EC 3.2.1.8) by an extreme thermophile Geobacillus thermoleovorans. The enzyme secretion was enhanced when the medium was supplemented with xylan (0.15%) and Tween-80 (0.1% v/v). In wheat bran-tryptone medium, the peak in enzyme production was attained within 42?h in a fermenter as compared to 72?h in shake flasks. Optimization of the culture conditions resulted in a 7.72-fold enhancement in enzyme production. The cellulase-free xylanase was optimally active at pH?8.5 and 80?C, and it was found to be useful in the pre-bleaching process of paper pulps.

The effect of 3 fermentation methods, in situ (IS) in 4 lactating cows (average pH of 5.8), in vitro (IVn) with media pH of 6.8, or in vitro (IVa) with media pH adjusted to 6.0 using citric acid, on fiber degradation parameters was studied using feeds ground to different particle sizes. Corn silage (CS), grass silage (GS), barley grain (B), sugar beet pulp (BP), and rapeseed cake (RC) were ground using a shear mill. Silages were ground through 8-, 4-, 2-, or 1-mm screens, B and BP through 4-, 2-, or 1-mm screens, and RC through 2- or 1-mm screens. The amylase-treated NDF (aNDF) content of samples ground using a 1-mm screen was 399, 431, 197, 480, and 251 g/kg of DM for CS, GS, B, BP, and RC, respectively, but increased with increasing screen size.

Four types of carbohydrate sources, sugar beet pulp (SBP), rye grass hay (RYE), alfalfa hay (ALF) and fructooligosaccharides (FOS) were used to investigate their effects on the metabolism of l-tryptophan to skatole and indole by a mixed bacterial population from the large intestines of pigs. Microbial suspensions were anaerobically incubated at 38??C, and indole compounds, pH value and volatile fatty acids were analyzed after 24?h fermentation. Effects of carbohydrate sources on the microbial diversity were analyzed using denaturing gradient gel electrophoresis (DGGE) of PCR amplicons of 16S rDNA, cloning and sequencing. Addition of SBP showed decreasing effect on skatole concentration and decreased the relative rate of skatole production significantly, whereas RYE and ALF treatments signi...

Five industrial Saccharomyces cerevisiae strains were evaluated for their suitability for strain improvement for future use in ethanol production processes. Principal components analysis of growth-related and production-related fermentation parameters of the 5 strains grown on glucose demonstrated the superiority of the Y9 strain in terms of its rapid growth and highest ethanol yields on both biomass and glucose. The growth and ethanol production performances of these strains on various agro-industrial wastes (including sugar beet pulp, starch and sugar beet molasses) and biological residues (including carrot, tomato and potato peel) were also determined. Ethanol tolerance studies, using both solid and liquid cultures, revealed the remarkable abilities of the BC187 and Y9 strains to surviv...

In batch experiments, pressed pulp was first converted anaerobically to biogas with adapted mixed cultures. Hydrolysis of the uncomminuted solids took place in two stages: pectin and the pentosans were decomposed first, and then the cellulose. Hydrolysis of the solids proved to be the slowest step in their fermentation. The effect of solids loading, residence time and biogas yield were examined in an experimental continuous two-stage unit. The solids loading in the first stage (the hydrolysis and acidification reactor) were between 5 and 15 g/(l/d) and the hydraulic residence time in the range from 10 to 30 hours, and, in the second stage (the methane reactor) 2 to 6 days. It was possible to maintain pH in the optimal range between 6.2 and 6.8 in the first stage without use of correcting means. The methane yields obtained in the two-stage system were approximately 90%. 30 references.

Dissolved lignocelluloses from the pre-hydrolysis liquor (PHL) of kraft-based dissolving pulp production process were recovered by adsorption to lime mud produced in the causticizing plant of the kraft process. The adsorption of lignocelluloses was a fast process, and could be completed within one hour. The addition of polydiallyldimethylammonium chloride (PDADMAC) significantly increased the amounts of adsorbed lignin and hemicelluloses, which more than doubled at the PDADMAC dosage of 0.1% (based on the weight of PHL). The measured heating values of the adsorbed lignocelluloses indicate that adsorption of lignocelluloses to lime mud may result in the energy saving of the lime kiln. The process proposed in this study could also be adapted to decrease inhibitor concentrations (lignin and acetic acid) if the dissolved hemicelluloses in the PHL were used to produce value-added products, e.g., ethanol, xylitol, based on the fermentation process. PMID:21907575

BACKGROUND: Cellulose acetate membranes are frequently used for pressure-driven membrane processes. The aim of this work was to prepare cellulose acetate membranes from nata-de-coco using coconut water as starting material. The use of this lignin-free material will certainly minimize the use of chemicals usually needed in the traditional pulps and substitute for the use of wood, which helps prevent global warming and preserves nature as well.RESULTS: Coconut water was fermented by Acetobacter xylinum for 6 days to produce nata-de-coco, which was then acetylated to produce cellulose diacetate with an acetyl content of 39.6%. Fourier transform infrared analysis showed characteristic peaks for the acetyl group at 1748 and 1236 cm-1. The resulting membranes made from the hydrolysis product sho...

The production of extracellular xylanase by a locally isolated strain of Aspergillus tubingensis JP-1 was studied under solid-state fermentation. Among the various agro residues used wheat straw was found to be the best for high yield of xylanase with poor cellulase production. The influence of various parameters such as initial pH, moisture, moistening agents, nitrogen sources, additives, surfactants and pretreatment of substrates were investigated. The production of the xylanase reached a peak in 8 days using untreated wheat straw with modified MS medium, pH 6.0 at 1:5 moisture level at 30 °C. Under optimized conditions yield as high as 6,887 ± 16 U/g of untreated wheat straw was achieved. Crude xylanase was used for enzymatic saccharification of agro-residues like wheat straw, rice bran, wheat bran, sugarcane bagasse and industrial paper pulp. Dilute alkali (1 N NaOH) and acid (1 N H(2)SO(4)) pretreatment were found to be beneficial for the efficient enzymatic hydrolysis of wheat straw. Dilute alkali and acid-pretreated wheat straw yielded 688 and 543 mg/g reducing sugar, respectively. Yield of 726 mg/g reducing sugar was obtained from paper pulp after 48 h of incubation. PMID:22271252

The side chains of the rhamnogalacturonan I fraction in sugar beet pectin are particularly rich in arabinan moieties, which may be substituted with feruloyl groups. In this work the arabinan-rich fraction resulting from sugar beet pulp based pectin production was separated by Amberlite XAD hydrophobic interaction and membrane separation into four fractions based on feruloyl substitution and arabino-oligosaccharide chain length: short-chain (DP 2–10) and long-chain (DP 7–14) feruloylated and nonferuloylated arabino-oligosaccharides, respectively. HPAEC, SEC, and MALDI-TOF/TOF analyses of the fractions confirmed the presence of singly and doubly substituted feruloylated arabino-oligosaccharides in the feruloyl-substituted fractions. In vitro microbial fermentation by human fecal samples (n = 6 healthy human volunteers) showed a selective stimulation of bifidobacteria by both the feruloylated and the nonferuloylated long-chain arabino-oligosaccharides to the same extent as the prebiotic fructo-oligosaccharides control. None of the fractions stimulated the growth of the potential pathogen Clostridium difficile in monocultures. This work provides a first report on the separation of potentially bioactive feruloylated arabino-oligosaccharides from sugar beet pulp and an initial indication of the potentially larger bifidogenic effect of relatively long-chain arabino-oligosaccharides as opposed to short-chain arabino-oligosaccharides.

To study the fermentation characteristics of different non-conventional dietary fibre (DF) sources with varying levels of indigestible CP content and their effects on the production of fermentation metabolites and on faecal nitrogen (N) excretion, an experiment was conducted with 40 growing pigs (initial BW 23 kg) using wheat bran (WB), pea hulls (PH), pea inner fibres (PIF), sugar beet pulp (SBP) or corn distillers dried grains with solubles (DDGS). The diets also contained soya protein isolate, pea starch and sucrose, and were supplemented with vitamin-mineral premix. Faecal samples were collected for 3 consecutive days from day 10, fed with added indigestible marker (chromic oxide) for 3 days from day 13 and pigs were slaughtered on day 16 from the beginning of the experiment. Digesta from the ileum and colon were collected and analysed for short-chain fatty acids (SCFA) and ammonia (NH3) content. The apparent total tract N digestibility was the lowest (P PIF and PH (79% and 81%, respectively). Expressed per kg fermented non-starch polysaccharides (NSP), faecal N excretion was higher with DDGS and WB diets (130 and 113 g/kg NSP fermented, respectively) and lower with PIF, PH and SBP diets (42, 52 and 55 g/kg NSP fermented, respectively). The PH-based diets had the highest (P < 0.05) SCFA concentrations, both in the ileum and the colon (27 and 122 mMol/kg digesta, respectively). The highest NH3 concentration was also found in the colon of pigs fed with PH (132 mMol/kg digesta). Loading plot of principle component analysis revealed that the CP : NSP ratio was positively related with faecal N excretion and NH3 concentration in colon contents, whereas negatively related with SCFA concentration in colon contents. In conclusion, pea fibres and SBP increased SCFA and reduced NH3 concentration in the pig's intestine and reduced faecal N excretion, which makes pea fibres and SBP an interesting ingredient to use in pig diet to improve the positive effect of DF fermentation on the gastrointestinal tract and reduce faecal N excretion. PMID:22436276

Abstract in portuguese Objetivou-se com este trabalho determinar o perfil fermentativo das silagens de quatro variedades de mandioca. No estudo do pH, do nitrogênio amoniacal, dos ácidos orgânicos, do índice de recuperação de matéria seca (MS) e da densidade das silagens, utilizou-se delineamento em blocos casualizados com esquema fatorial 4 × 3, com quatro repetições, sendo quatro variedades de mandioca (Amarelinha, Olho Roxo, Periquita e Sabará) e três frações da parte aérea (p (more) lanta inteira, sobras do plantio e terço superior). No estudo da perda de matéria seca por gases e efluentes, o esquema fatorial utilizado foi 4 × 3 × 7, com quatro repetições, composto de quatro variedades de mandioca, três frações da parte aérea e sete datas de abertura dos silos (1, 3, 5, 7, 14, 28 e 56 dias após a ensilagem). A ensilagem foi realizada em silos de laboratório confeccionados em tubos de PVC. Os dados obtidos foram submetidos à análise de variância e, para comparação das médias, foi realizado o teste de Scott-Knott a 5% de significância. Não houve diferença significativa entre os valores de pH, ácidos orgânicos e densidade das silagens das diferentes variedades, entretanto, o pH, o nitrogênio amoniacal e a densidade das silagens das frações da parte aérea diferiram entre as variedades. O nitrogênio amoniacal das silagens também diferiu entre as variedades. Embora a forragem fresca tenha apresentado valores de matéria seca inferiores a 30%, os valores de pH foram satisfatórios. As silagens das frações terço superior e sobras do plantio têm ótima qualidade fermentativa. As silagens deste estudo apresentam baixa perda de matéria seca. Abstract in english The objective of this work was to determine fermentative profile of silage of four cassava varieties. In the study of pH, ammonia nitrogen, organic acid, dry matter (DM) recovery index and silage densities, it was used a 4 × 3 factorial arrangement, with four repetitions, four cassava varieties (Amarelinha, Olho Roxo, Periquita and Sabará) and three aerial part fractions (entire plant, surpluses of the planting and superior third). In the study of dry matter loss by gas (more) es and effluents, it was used a 4 × 3 × 7 factorial arrangement, with four replicates, composed of four cassava varieties, three aerial section fractions and seven silo opening dates (1, 3, 5, 7, 14, 28 and 56 days after ensilage). Ensilage was done in laboratory silos made of PVC pipes. The obtained data were submitted to analysis of variance and for average comparison effect, the test of Scott-Knott was performed at the 5% level of significance. There was no significant difference among pH values, organic acid and silage densities of the different varieties but pH, ammonia nitrogen and silage densities of aerial section fractions differed among varieties. Ammonia nitrogen of silages also differed among varieties. Although fresh forage had presented dry matter values lower than 30%, values of pH were satisfactory. Silages of superior-third fractions and plant remains present great fermentative quality. Silages of this study present low dry matter loss.

The Guangxi Zhuang autonomous region has plentiful cassava resources, which is an ideal feedstock for fuel ethanol production. The Guangxi government intends to promote cassava fuel ethanol as a substitute for gasoline. The purpose of this study was to quantify the energy efficiency and potentials of a cassava fuel ethanol project in the Guangxi region based on a 100 thousand ton fuel ethanol demonstration plant at Qinzhou of Guangxi. The net energy value (NEV) and net renewable energy value (NREV) are presented to assess the energy and renewable energy efficiency of the cassava fuel ethanol system during its life cycle. The cassava fuel ethanol system was divided into five subsystems including the cassava plantation/treatment, ethanol conversion, denaturing, refueling and transportation. All the energy and energy related materials inputs to each subsystem were estimated at the primary energy level. The total energy inputs were allocated between the fuel ethanol and its coproducts with market value and replacement value methods. Available lands for a cassava plantation were investigated and estimated. The results showed that the cassava fuel ethanol system was energy and renewable energy efficient as indicated by positive NEV and NREV values that were 7.475MJ/L and 7.881MJ/L, respectively. Cassava fuel ethanol production helps to convert the non-liquid fuel into fuel ethanol that can be used for transportation. Through fuel ethanol production, one Joule of petroleum fuel, plus other forms of energy inputs such as coal, can produce 9.8J of fuel ethanol. Cassava fuel ethanol can substitute for gasoline and reduce oil imports. With the cassava output in 2003, it can substitute for 166.107 million liters of gasoline. With the cassava output potential, it can substitute for 618.162 million liters of gasoline. Cassava fuel ethanol is more energy efficient than gasoline, diesel fuel and corn fuel ethanol but less efficient than biodiesel. (author)

A total of 375 lactic acid bacteria were isolated from fermenting cassava in South Africa, Benin, Kenya and Germany, and were characterised by phenotypic and genotypic tests. These could be divided into five main groups comprising strains of facultatively heterofermentative rods, obligately heterofermentative rods, heterofermentative cocci, homofermentative cocci and obligately homofermentative rods, in decreasing order of predominance. Most of the facultatively heterofermentative rods were identified by phenotypic tests as presumptive Lactobacillus plantarum-group strains, which also comprised the most predominant bacteria (54.4% of strains) isolated in the study. The next predominant group of lactic acid bacteria (14.1% of total isolates) consisted of obligately heterofermentative rods belonging either to the genus Lactobacillus or Weissella, followed by the heterofermentative cocci (13.9% of isolates) belonging to the genera Weissella or Leuconostoc. Homofermentative cocci were also isolated (13.3% of isolates). Biochemical properties such as production of alpha-amylase, beta-glucosidase, tannase, antimicrobials (presumptive bacteriocin and H(2)O(2)-production), acidification and fermentation of the indigestible sugars raffinose and stachyose, were evaluated in vitro for selection of potential starter strains. A total of 32 strains with one or more desirable biochemical properties were pre-selected and identified using rep-PCR fingerprinting in combination with 16S rRNA sequencing of representative rep-PCR cluster isolates. Of these strains, 18 were identified as L. plantarum, four as Lactobacillus pentosus, two each as Leuconostoc fallax, Weissella paramesenteroides and Lactobacillus fermentum, one each as Leuconostoc mesenteroides subsp. mesenteroides and Weissella cibaria, while two remained unidentified but could be assigned to the L. plantarum-group. These strains were further investigated for clonal relationships, using RAPD-PCR with three primers, and of the 32 a total of 16 strains were finally selected for the development as starter cultures for Gari production. PMID:17188771

In the present study, a total of 116 lactic acid bacteria (LAB) strains isolated from Mill flour and fermented cassava were screened for their antifungal activity. Three strains among 116 were selected for their strongest inhibitory activity against food molds. These 3 strains were?Lactobacillus plantarum?VE56,?Weissella cibaria?FMF4B16, and?W. paramesenteroides?LC11. The compounds responsible for the antifungal activity were investigated. The strains displayed an inhibitory activity against targeted molds at acidic pH. However, the influence of organic acids was rejected according to the calculated minimal inhibitory concentration (MIC). Antifungal compounds were investigated in the cell-free supernatants and phenyllactic acid (PLA) was detected in different amounts with a maximal concentration for?Lb. plantarum?VE56 (0.56 mM). Hydroxy fatty acid, such as 2-hydroxy-4-methylpentanoic acid, was also produced and involved in the inhibitory activity of?Lb. plantarum?VE56 and?W. paramesenteroides?LC11. Antifungal LAB are known to produce PLA and 3-hydroxy fatty acids and other organic acids with antifungal activity. This short communication focuses on antifungal activity from?Weissella?genus. The antifungal activity was attributed to antifungal compounds identified such as PLA, 2-hydroxy-4-methylpentanoic acid, and other organic acids. Nevertheless, the concentration produced in the cell-free supernatant was too low to compare to their MIC, suggesting that the inhibitory activity was caused by a synergy of these different compounds. PRACTICAL APPLICATION: Antifungal LAB are interesting to prevent food spoilage in fermented food and prolong their shelf life. In this way, chemical preservatives could be avoided and replaced by natural preservatives. PMID:21729073

The cross-flow filtration characteristics of bacterial cells (S. bovis) obtained from a lactic acid fermentation broth of fresh cassava roots have been investigated in terms of specific cake resistance. The amount of particles accumulated on the membrane surface was evaluated using a cake filtration model. The effects of the operating conditions (transmembrane pressure, cross-flow velocity and cell concentration) on permeate flux, cake resistance and specific cake resistance were studied. The cake properties in cross-flow filtration were then compared to those in dead-end filtration. The specific cake resistance in the cross-flow filtration shows a higher value than in the dead-end filtration for almost the same cake compressibilities of about 1.0. The specific cake resistance increases with increasing cross-flow velocity and decreases with increasing cell concentration until reaching a concentration at which the specific cake resistance hardly changes. The increasing ratio of the specific cake resistance in the cross-flow filtration over the dead-end filtration is found to be independent of the transmembrane pressure and cell concentration.   

The effect of combined heat treatment and acid hydrolysis (various concentrations) on cassava grate waste (CGW) biomass for ethanol production was investigated. At high concentrations of H{sub 2}SO{sub 4} (1--5 M), hydrolysis of the CGW biomass was achieved but with excessive charring or dehydration reaction. At lower acid concentrations, hydrolysis of CGW biomass was also achieved with 0.3--0.5 M H{sub 2}SO{sub 4}, while partial hydrolysis was obtained below 0.3 M H{sub 2}SO{sub 4} (the lowest acid concentration that hydrolyzed CGW biomass) at 120 C and 1 atm pressure for 30 min. A 60% process efficiency was achieved with 0.3 M H{sub 2}SO{sub 4} in hydrolyzing the cellulose and lignin materials present in the CGW biomass. High acid concentration is therefore not required for CGW biomass hydrolysis. The low acid concentration required for CGW biomass hydrolysis, as well as the minimal cost required for detoxification of CGW biomass because of low hydrogen cyanide content of CGW biomass would seem to make this process very economical. From three liters of the CGW biomass hydrolysate obtained from hydrolysis with 0.3M H{sub 2}SO{sub 4}, ethanol yield was 3.5 (v/v%) after yeast fermentation. However, although the process resulted in gainful utilization of CGW biomass, additional costs would be required to effectively dispose new by-products generated from CGW biomass processing.

A study was conducted on the microbiological quality of traditionally fermented cassava flour 'kpor umilin' and a laboratory modification of the method developed with a view to upgrading the traditional process. Microbial analysis of samples from both processing methods was evaluated using standard microbiological methods. The bacterial count in the traditionally processed flours ranged from 2.7 x 10(3) to 1.2 x 10(7) cfu/g, while the modified sample had a count of 3.5 x 10(2) cfu/g. The predominant flora were Leuconostoc spp., Lactobacillus spp., Staphylococcus spp., Micrococcus spp., Bacillus spp., Streptococcus spp. and coliforms such as Escherichia coli. Other isolates were Enterobacter spp. and proteus spp. The sample from the modified method had a negligible (4 MPN/100 ml) coliform count. The yeast and mould count ranged from 1.9 x 10(3) cfu/g to 3.9 x 10(5) cfu/g in the traditionally processed samples as compared with 1.5 x 10(3) cfu/g in the sample from the modified process. Aspergillus spp., Penicillium spp., Saccharomyces spp. and Geotrichum candidum were the predominant fungi. The poor microbiological quality of 'kpor umilin', processed traditionally, calls for urgency in upgrading the processing and preservation methods as developed in this study as well as proper education of the local processors on good manufacturing practices. PMID:15369985

Abstract in spanish En la actualidad se desarrollan numerosas investigaciones para la producción de alcohol a partir de biomasa lignocelulósica. En este estudio, se evaluó el etanol producido a partir de pulpa y mucílago de café, levadura comercial y panela (jugo de caña solidificado y deshidratado). La pulpa y el mucílago del café se hidrolizaron vía acida y el mosto (jugo de pulpa y mucilago) se fermentó con un inóculo de Saccharomyces cerevisiae en fase exponencial, elaborado c (more) on panela entera comercial. El producto fermentado se destiló y su análisis mediante cromatografía de gases arrojó un resultado de 25,44 kg/m³ de etanol a partir de 64,40 kg/m³ de azúcares totales, lo que equivale a un rendimiento del 77,29% respecto al teórico; mostrando que es posible su obtención en pequeñas fincas cafeteras con materias primas de fácil acceso. Se analizaron las vinazas resultantes del proceso, reportando valores de 0,40 ppm (Hierro), 0,97 ppm (Magnesio), 1,54 ppm (Calcio), y 4,40 ppm (Fósforo), lo que las hace particularmente útiles como complemento en el desarrollo de biofertilizantes para la lombricultura. Abstract in english Currently, many research studies are being carried out on the production of alcohol from lignocellulosic biomasses. In this study, the ethanol obtained from a mixture of coffee pulp and mucilage, commercial baker's yeast and panela (dehydrated and solidified cane juice) was evaluated. The pulp and mucilage of coffee underwent an acid hydrolysis, and the wort (pulp juice and mucilage) was fermented with an inoculum of exponential phase Saccharomyces cerevisiae and commerci (more) al whole panela. The fermented product was distilled, and the gas chromatographic analysis showed an ethanol yield of 25.44 kg/m³, resulting from the 64.40 kg/m³ of total sugars, such yield is equivalent to 77.29% of the theoretical yield. This fact shows that the production of ethanol is viable in small coffee farms using readily available raw materials. The stillage was analyzed and it presented the following values: 0.40 ppm (Iron), 0.97 ppm (Magnesium), 1.54 ppm (Calcium), and 4.40 ppm (Phosphorus). The results confirm that they are particularly useful as a complement in the production of bio-fertilizers for earthworms.

The baobab milk and fermented baobab/acha flour mixtures were analyzed chemically for their proximate, ascorbate, mineral and antinutrient composition. The dry pulp scraped from baobab fruits was kneaded, made into solution, extracted through cheese-cloth and stored frozen until analyzed. The acha and baobab grains were cleaned, fermented for 24 to 120 hours, dried and hammermilled into fine flours. The unfermented flours served as controls. The standard assay methods of AOAC were selected for use for the analysis of the nutrients and the antinutrients. The mixtures were composed of 70% acha and 30% baobab flours (70:30 protein basis). The baobab milk contained more protein (1.5%) and minerals (Fe, 17.8 mg; Ca 134.2 mg) than those of human milk (protein, 1.3%, Fe, 0.2 mg, Ca 30 mg) and cow milk (Fe, 0.1 mg; Ca 1.20 mg) and most leading national commercial infant formulas e.g. cerelac (Fe, 10.0 mg). The composite flours contained more nutrients than the baobab or the acha flour alone. The BF96 had greater advantage over other BF flours as a supplement to acha. The mixtures are within the reach of lower income group and can be incorporated into their diets. PMID:7855083

The feasibility of cellulase production by Trichoderma reesei using inexpensive lignocellulosic material was examined. Sulfite pulp used as standard substrate yielded 3.7 IU/ml filter paper units (FPU) and 2.15 IU/ml ..beta..-glucosidase. The yield was 185 FPU per gram total carbohydrate (CH) in the fermentation medium. Steam treated wheat straw (2%) gave 1.9 FPU/ml, 0.83 IU/ml ..beta..-glucosidase and 151 FPU/g CH, whereas the spent fibres remaining after enzymatic hydrolysis of steamed wheat straw gave 2.4 FPU/ml, 1.55 IU/ml ..beta..-glucosidase and 147 FPU/g CH. A good substrate (3%) was also the combustible fraction of municipal waste (BRAM) treated with NaOH, which gave 2.5 FPU/ml, 0.86 IU/ml ..beta..-glucosidase and 130 FPU/g CH. A further increase in the final enzyme titer is obtainable by increasing the substrate concentration. In shake cultures 5% steamed wheat straw gave 3.8 FPU/ml and 1.95 IU/ml ..beta..-glucosidase. Untreated wheat straw gave only low final enzyme titers and low yields of FPU/g CH. In the case of lignocellulosic substrates a constant pH-value of pH 6.0 during the fermentation gave optimal yields.

Recently there has been much interest in developing processes for producing liquid fuels from renewable resources. The most logical long term approach in terms of economics derives the carbohydrate substrate for fermentation from the hydrolysis of cellulosic crop and forest residues rather than from grains or other high grade food materials (1,2). Since the presence of lignin is the main barrier to the hydrolysis of cellulose from lignocellulosic materials, delignification processes developed by the wood pulping industry have been considered as possible prehydrolysis treatments. The delignification process under study in our laboratory is envisioned as a synthesis of two recently developed pulping processes. In the first step, called autohydrolysis, hot water is used directly to solubilize hemicellulose and to depolymerize lignin (3). Then, in a second step known as organosolv pulping (4), the autohydrolyzed material is extracted with aqueous alcohol. A s shown in Figure 1, this process can separate the original lignocellulosic material into three streams--hemicellulose in water, lignin in aqueous alcohol, and a cellulose pulp. Without further mechanical milling, delignified cellulose can be enzymatically hydrolyzed at 45-50 C to greater than 80% theoretical yield of glucose using fungal cellulases (5, 6). The resulting glucose syrup can then be fermented by yeast to produce ethanol or by selected bacteria to produce acetone and butanol or acetic and propionic acids (7). One objection to such a process, however, is the large energy input that is required. In order to extend our supplies of liquid fuels and chemicals, it is important that the use of fossil fuels in any lignocellulosic conversion process be minimized. The direct use of geothermal hot water in carrying out the autohydrolysis and extraction operations, therefore, seems especially attractive. On the one hand, it facilitates the conversion of non-food biomass to fuels and chemicals without wasting fossil fuel; and on the other hand, it provides a means for ''exporting'' geothermal energy from the well site. The primary goal of the work discussed in this report was to investigate the effects of variations in autohydrolysis conditions on the production of fermentable sugars from wheat straw. In assessing the relative merits of various sets of conditions, we considered both the direct production of sugar from the autohydrolysis of hemicellulose and the subsequent yield from the enzymatic hydrolysis of cellulose. The principal parameters studied were time, temperature, and water/fiber weight ratio; however, we also investigated the effects of adding minor amounts of phenol and aluminum sulfate to the autohydrolysis charge. Phenol was selected for study because it was reported (8) to be effective in suppressing repolymerization of reactive lignin fragments. Aluminum sulfate, on the other hand, was chosen as a representative of the Lewis acids which, we hoped, would catalyze the delignification reactions.

Cassava mosaic geminiviruses (CMGs) are implicated in cassava mosaic disease (CMD), the main constraint to cassava production in Africa. Here, we report the complete nucleotide sequences of the DNA-A and DNA-B of a newly characterized CMG found infecting cassava in Madagascar, for which we propose the tentative name cassava mosaic Madagascar virus. With the exception of two recombinant regions that resembled a CMG, we determined that the non-recombinant part of the DNA-A component is distantly related to the other CMGs. Whereas the DNA-B component possesses one recombinant region originating from an unidentified virus, the rest of the genome was seen to be closely related to members of the species East African cassava mosaic Zanzibar virus (EACMZV). Phylogenetic analysis based on complete ...