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1.
Bambara groundnut, an indigenous African legume, was subjected to fermentation by three strains of Rhizopus. One strain B. arrhizus could not ferment the substrate. Mycelial penetration and binding was good when strains NRRL 2710 ( R. oligosporus) and NRRL 1477 ( R. stolonifer) were used. Fermentation by both strains resulted in increases of pH, moisture, protein and fat while total carbohydrate decreased by 50%. Sensory evaluation showed that bambara groundnut tempes rated similar (p>0.5) in taste and texture and higher (p<0.05) in color and flavor than soybean tempe. Bambara groundnut would be an acceptable food product in the diet as a good protein supplement.  相似文献   

2.
Soaking three beans cultivars (Phaseolus vulgaris L.: Great Northern, kidney, and pinto) in mixed salt solution (sodium chloride 2.5% + sodium bicarbonate 1.5% + sodium tripolyphosphate 1.0% + sodium carbonate 0.5%) resulted in 80%–85% reduction in cooking time over corresponding controls. Irradiation (-rays) at 500 krads of soaked and dehydrated beans caused a reduction of nearly 50% in cooking time. Water uptake and leaching losses for each treatment during soaking at 22°, 37°, and 45°C were investigated. High temperature (37° and 45°C) and pH (9.0) caused greater water imbibition and total solid loss than at room temperature (22°C). Organoleptic evaluation revealed that quick-cooking Great Northern beans appear to be more acceptable than kidney and pinto beans. Quick-cooking cooked beans had better in vitro protein digestibility than conventionally cooked beans. Phenolic content was found to be inversely related to in vitro digestibility.Utah Agricultural Experiment Station Journal article no. 2481.  相似文献   

3.
Rice-defatted soy flour blends prepared in three proportions viz. 40:60, 50:50 and 60:40 were fermented with buttermilk at 25, 30 and 35°C for 12, 18 and 24h. Fermentation of these blends lowered the pH and raised the titratable acidity, maximum drop in pH and rise in titratable acidity being observed at 35°C for 24h. The fermentation either decreased or did not change the protein content of cereal-legume blends. Fat as well as ash content remained unaltered irrespective of temperature and time period of fermentation.  相似文献   

4.
A good quality wine was produced from African bush mango (Irvingia var.gabonensis). Analysis of the African bush mango juice showed that it contained 3.6% total sugar, 1.09% protein, 4.2° Brix soluble solids (SS) 0.5% ash, 50.24% total solids (TS), 66.7 mg/100 ml ascorbic acid and pH 5.12. The juice ameliorated to 23° Brix was inoculated with 3% (w/v) Baker's yeast (Saccharomyces cerevisiae) and held at 30±2°C for 28 days. SS and pH decreased while titratable acidity (TA) increased with increasing period of fermentation. Fermentation was 110% efficient. The wine produced had 8.12% (v/v) alcohol, 0.78% protein, 6.5% Brix SS, 0.64 g/100 ml TA, and a pH 3.10. Sensory evaluation results showed that there was no significant difference (p=0.05) in colour, mouthfeel, sweetness, flavour and general acceptability, between African Bush mango wine and a reference wine. The wine was generally accepted.  相似文献   

5.
The phytic acid content of four different varieties of beans under different processing conditions was estimated. It was highest in red kidney (1.86–2.13%) slightly lower in pigeon (1.86–2.03%), white (1.80–1.96%) and black eyed beans (1.15–1.64%). There was no significant change in phytic acid content of beans after soaking at 25°C for 22 hours. However, both soaking and cooking revealed 26–37% loss of phytic acid in all four varieties of beans.The rate of in vitro casein digestibility with and without phytic acid at concentrations found in legumes was determined at pH 8 and 37°C using multienzyme technique. Addition of 5 mg Na-phytate reduced the casein digestibility up to 20% compared to the control. However, only 25% reduction of casein digestibility was observed in the presence of 25 mg of Na-phytate. Higher concentration of Na-phytate had no significant effect on the rate of casein digestibility. Data strongly suggest the formation of protein phytate complex at alkaline pH of small intestine.Part of this work was presented at the XIII International Congress of Nutrition in Brighton, UK in August 1985.  相似文献   

6.
Two common bean (Phaseolus vulgaris) varieties were seeded in the same location, harvested and cleaned. Three hardening procedures were used (soaking in acetate buffer, pH 4.1 at 37°C for 5 h; storage at 37°C, 100% RH for 28 days; and storage at 31–33°C, 76% RH for 120 days) to have seeds in a hard-to-cook (HTC) state. The adverse effects of HTC condition, in terms of cooking time as assessed by a Mattson bean cooker, were practically eliminated by soaking seeds in salt solutions (1% NaCl+0.75% NaHCO3; and 0.75% NaHCO3) instead of only water. Ultrastructural changes of cotyledon cells from fresh, HTC and softened seeds were observed. Results of this study may be used for the development of a technological procedure to utilize properly HTC beans generated by unefficient storage systems.  相似文献   

7.
Studies on the enhancement of the traditional production of Ugba (a protein-rich fermented food) from African oil bean seeds were undertaken by fermenting the bean seeds at different temperatures, relative humidities (RH) and microenvironments. Fermentation was monitored by pH, texture, amino-nitrogen content and the viable cell count of the substrate. The 40 °C, 98% RH or the 130 m high density polyethylene (HDPE) treatment increased the fermentation microflora from ca. 106 CFU/g to ca. 108 CFU/g with high initial changes in pH (5.8–ca. 7.9) and texture (2.0 kg/cm2 to between 1.4 kg/cm2 and 0.9 kg/cm2) in 24 hours. Products with amino-nitrogen contents of between 12.00 mg N/100 g dry matter and 14.00 mg N/100 g dry matter were obtained in 3 days. The cell count of the 30 °C, 80% RH or 70 m treatment increased from 106 CFU/g to ca. 107 CFU/g and the pH increased from 5.8 to about 6.7 with a coincident decrease in the texture value from 2.0 kg/cm2 to about 1.7 kg/cm2 in 24 hours. Products with amino-nitrogen contents between 15.00 mg N/100 g dry matter and 19.2 mg N/100 g dry matter were obtained after 3 days. Changes in the fermentation indicators were not significant at p0.05 (pH and texture) and at p0.01 (amino-nitrogen) after 3 days for the 25 °C, 59.9% RH or 50 m low density polyethylene (LDPE) treatment. Products of fermentation at the combined optimal conditions (80% RH, 35 °C and 70 m HDPE) compared very well with the traditionally fermented products in terms of pH, texture and amino-nitrogen content.  相似文献   

8.
Germinated bambara groundnut was dried by three methods – oven-drying at 50 °C, in a solar drier at 38–42 °C, and sun drying at 28 ± 2 °C. The samples were milled into flour, and made into okpa, a steamed gel. Flour yield increased only in oven-dried malts. The quality of the okpa based on appearance and taste decreased with malting time; solar drying resulted in the poorest product because of its dark color.  相似文献   

9.
Biochemical changes in wheat grains stored at 10, 25 and 45 °C for six months were studied. A significant decrease in pH and an increase in titratable acidity was observed during storage of wheat grains at 25 °C and 45 °C. Moisture contents of wheat grains decreased by 15% at 25 °C and 26% at 45 °C during six months of storage. A significant decrease in water soluble amylose (20–28%) along with an increase in insoluble amylose contents (7.6–17%) were observed during storage at 25 and 45 °C. Amylase activity of the samples showed a decrease as the storage progressed. Total soluble sugars increased by 9% at 10 °C and 12% at 25 °C; a 37% decrease was observed after six months storage at 45 °C. Total available lysine decreased by 18.0% and 22.6% at 25 and 45 °C, respectively, after six months storage. In vitro protein digestibility of wheat grains decreased by 5.00% at 25 °C and 10.28% at 45 °C during six months of storage. However, no significant biochemical changes occurred during storage at 10 °C.  相似文献   

10.
Thirty-six adult Wistar albino male rats (75–128 g) of age 8 weeks were used to study the effect of dehulled and soaked bambara groundnut combined with sorghum or crayfish on iron and phosphorus balances of rats fed for 10 days. Three out of the ten days were for adjustment and the rest for the balance period. Six diets were formulated and fed to the rats. The mixed protein diets provided 10% protein daily for the entire study period. Casein(CA) served as a reference protein. Rats fed the CA diet had significant decreases (p < 0.05) in food intake, maintenance body weight, phosphorus intake and phosphorus balance when compared with those of the test groups. As judged by iron nutriture, dehulled brown bambara groundnut (DBGB) appeared to be superior to the white variety. Soaking seriously affected iron utilization in brown variety. Dehulling produced significant increases (p < 0.05) in phosphorus balance in animals fed the white variety of bambara groundnut compared with the brown variety. On the other hand, soaking produced positive phosphorus balance in rats consuming the brown variety. Addition of crayfish produced a slight nonsignificant decrease (p > 0.05) in rodents eating the brown variety. These results suggested that varietal difference and treatment affected iron and phosphorus utilization in rats fed bambara groundnut in conjunction with sorghum and/or crayfish.  相似文献   

11.

Cocoa beans and cocoa products contain considerable amounts of bioactive compounds. Harvesting cocoa fruit too early or too late may have effects on the phenolic and alkaloid concentrations of the cocoa powder. Fermentation, a primary processing used to transform cocoa beans to cocoa powder, may also influence the contents of bioactive compounds. In this study, proanthocyanidins, the major compounds in cocoa polyphenols, caffeine and theobromine of cocoa beans, were evaluated at different maturities at harvest, and with different fermentation durations, with and without the addition of a commercial enzyme, Pectinex® Ultra SP-L. The amounts of proanthocyanidins, caffeine and theobromine, and the antioxidant capacities of the unfermented cocoa beans increased as the fruits matured. The values ranged from 16.12–27.28 g catechin equivalents (CE)/100 g dry weight (DW); 99.66–173.61 mg/100 g DW; 556.39–948.84 mg/100 g DW; 23.23–26.32 mol Trolox equivalents (TE)/100 g DW, respectively. Prolonged fermentation with or without the addition of pectinase, from three to seven days, significantly reduced the amounts of these compounds present. Fermentation using the enzyme significantly reduced the proanthocyanidin content and antioxidant capacity of the cocoa powder, with the overall means decreasing from 8.93–4.93 g CE/100 g DW and from 15.81–12.95 g mol TE/100 g DW, respectively. Two-way ANOVA analyses showed that the proanthocyanidins, caffeine, theobromine contents and the antioxidant capacity of cocoa beans were strongly dependet to their stages of maturity, fermentation methods and fermentation duration.

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12.
Changes in pH, titratable acidity, total soluble solids and proteins ofDabar sorghum (Sorghum bicolor (Linn) Moench.) during naturalfermentation at 37 °C for up to 36 h were monitored. The pH ofthe fermenting material decreased sharply with a concomitant increase in the titratable acidity. Total soluble solids increased with progressivefermentation time. The crude protein and non-protein nitrogen slightlyincreased during the last stages of fermentation. The in vitroprotein digestibility markedly increased as a result of fermentation.The globulin plus albumin fractions increased significantly (p 0.05)during the first 8 h of fermentation. Kaffirin fraction decreasedduring the first 8 h of fermentation but increased sharply as fermentationprogressed. Cross-linked kaffirins fluctuated during the fermentationprocess. Glutelin like protein, which was the minor fraction, trueglutelins, the second most abundant fraction, together with non-extractableproteins fluctuated during the fermentation process.  相似文献   

13.
Five cultivars of bambara groundnut were selected on which to study the effects of germination and fermentation on their proximate composition. The cultivar that had the highest protein content was chosen to prepare unfermented and fermented milk. Standard assay techniques were adopted to determine the parameters selected for use. Germination caused a decrease in the protein, carbohydrate and starch; it increased sugar content, and had varied effects on the lipids contents of the dry samples. The anti-nutritional factor-tannin concentration was decreased. Germination and fermentation had varied effects on the nutrient compositions of the milk. Compared to the control, germination had the same effect as in the seeds. Fermentation further decreased some of the nitrogenous constituents, sugar and starch content of the milk and much more drastically the tannin content. Hydrolysis and other metabolic changes freed the nutrients from their bound forms while decreasing the quantity, but increasing the quality and availability of the nutrients.  相似文献   

14.
The effect of different heat treatments on inactivation of trypsin inhibitor and hemagglutinin of winged bean was investigated. Trypsin inhibitor extracted from winged bean meal was stable at 60 °C for 60 min. At 80 °C, the activity of the extracted inhibitor decreased by 25% within 5 min, and continued to decline gradually to a loss of 45% of activity after 30 min. When the extracted inhibitor was incubated at 100 °C, it exhibited a triphasic pattern of inactivation. The winged bean extract incubated at 60 °C lost 60% of its hemaggluinating activity within 30 min. At 80 °C, there was a complete loss of activity within 5 min. The microwave treatment to winged bean meal had no effect on trypsin inhibitor or hemagglutinating activities in the meal. However, infrared treatment to winged bean seeds for 60 seconds was effective in destroying most of the trypsin inhibitor and hemagglutinating activities. Autoclave treatment (120 °C at 15 lb pressure) for 10 min inactivated trypsin inhibitor and hemagglutinin in winged bean meal almost completely. Cooking of presoaked beans in boiling water for 30 min was effective in destroying most of the trypsin inhibitor and hemagglutinating activities.  相似文献   

15.
With the view of preparing semi-liquid weaning foods of high energy content, the influence of roasting (stationary hot air treatment) and fermentation (with natural and pure culture inocula) on the viscosity of maize-sorghum-soya porridges was investigated. Roasting resulted in porridges of significantly higher viscosity (cooked porridge cooled to 40 °C). Porridges made from the individual ingredients (maize, sorghum, soya) did not show this behaviour. Natural fermentation of mixed ingredients resulted in lower porridge viscosities (cooked porridge cooled to 40 °C, as well as hot-paste peak viscosity) when pH was 5.0–5.5. At lower pH the viscosity of the final porridges increased. Fermentation experiments of individual ingredients inoculated with pure cultures ofLactobacillus plantarum andCandida famata lead to the conclusion that various factors contribute to the effect of fermentation on porridge viscosity. Porridges of minimum viscosity are obtained at pH 5.0–5.5 corresponding with a moderate extent of fermentation. From a consumer safety point of view, it would be preferable to acidify to lower pH values (pH<4.5). If necessary, viscosity adjustments could be made using malted cereals.  相似文献   

16.
Effect of blanching time, salt concentration and fermentation on texture of green beans (var. Tuf) was determined. Beans were blanched at 90 °C for 1, 10 or 20 minutes and fermented with brine containing 3.08 and 4.6% salt (corresponding to 1.2 and 1.8% salt in the finished product). The beans were assessed for texture mechanically using Universal Testing Machine (Model 1011, Instron). Sensory evaluation was carried out to assess the taste, texture and overall acceptability of the products. Pectolytic enzyme (pectinestarase and exopolygalacturonase) activities were determined in fresh and fermented beans. Increase in blanching time improved the texture significantly. Significant (p<0.05) decreases in shearing energy of the beans were observed in the first two days of fermentation and, thereafter, there were no significant (p>0.05) changes except for samples blanched for one minute. Salt concentration showed a small but significant effect on texture only in samples blanched for one minute and this was probably due to activation by salt of residual pectolytic enzymes in the beans. Most acceptable beans were those blanched for 20 minutes and fermented with 1.2% salt brine.  相似文献   

17.
Fermentation of raw as well as autoclaved wheat flour with buttermilk at 30, 35 and 40°C for 6, 12, 18, 24 ad 48h significantly decreased the level of phytic acid; maximum decrease was observed at 40°C for 48h. Starch as well as protein digestibility (in vitro) improved with an increase in temperature and period of fermentation. Phytic acid had a significant (P<0.05) negative correlation with digestibility (in vitro) of both starch and protein ofrabadi.  相似文献   

18.
Natural as well as single, mixed and sequential pure cutlure (S. diastaticus, S. cerevisiae, L. brevis andL. fermentum) fermentations of pearl millet flour for 72h lowered pH and raised titratable acidity. The fermentation either decreased or did not change the protein content of pearl millet flour. Natural fermentation increased whereas pure culture fermentation decreased the fat content. Ash content did not change. Natural fermentation at 20°C and 25°C increased whereas at 30°C it decreased the thiamine content of the pearl millet flour. Yeast fermentation raised the level of thiamine two- to three-fold, while lactobacilli fermentation lowered it significantly.  相似文献   

19.
The storage stability of melon milk at room (30 ± 2 °C)and refrigeration (10 ± 2 °C) temperatures was determined by analyzing changes in the chemical, microbial andsensory properties of the milk stored for 7 days. Theresults showed that at both storage temperatures, solublesolids and pH of the milk decreased while titratableacidity increased with storage. The standard plate countsincreased appreciably while coliforms were absent in themilk with storage at both storage temperatures. The overallacceptability score of the melon milk dropped duringstorage, the drop being faster at 30 ± 2 °C than at 10 ± 2 °C. The milk samples stored at 30 ± 2 °C and 10 ± 2 °C were acceptable only within one and three days, respectively; thereafter, theywere unacceptable.  相似文献   

20.
Bambara groundnut is a leguminous crop that originated in West Africa. It is a drought-tolerant crop and has the potential to provide improved food and nutritional security in the dry areas of Africa. However, the plant contains anti-nutritional factors that affect its food value chain. The objective of this study was to assess the content of four major anti-nutritional factors in 30 bambara groundnut accessions in South Africa. The seeds of the bambara groundnut landraces were ground to make a fine powder and assessed for condensed tannins (CTs), phytic acid phosphate (PAP), polyphenol, and trypsin inhibitor content. Each assay was done in triplicate. The content of the four anti-nutritional compounds varied widely among the bambara groundnut accessions. The mean values for CTs ranged between 0.2 and 6.2 mg/g of prodephinidin equivalent, whereas that of the PAP was between 1.4 and 4.9 mg/g. A low mean polyphenol content of 0.4 mg/g of GA (gallic acid) equivalent was observed among the accessions. The level of trypsin inhibitor ranged from 5.3 to 73.4 TI/mg. With the exception of CTs and trypsin inhibitor, no significant correlation was observed among the four anti-nutritional factors assessed in this study. Generally, higher levels of anti-nutrients were observed in this study compared with certain studies reported earlier.  相似文献   

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