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1.
Single as well as mixed culture fermentations by yeasts (S. diastaticus;S. cerevistiae) and lactobacilli (L. brevis;L. fermentum) at 30 °C for 72 h improved the starch and protein digestibility (in vitro) of pearl millet flour significantly. The flour fermented bySaccharomyces diastaticus, a starch hydrolysing yeast, had the highest starch digestibility whereas fermentation bySaccharomyces cerevisiae enhanced the in vitro protein digestibility of the flour significantly. Weaning mixtures prepared from the fermented flour were also found to be organoleptically acceptable.  相似文献   

2.
Sequential culture fermentation by yeasts (S. diastaticus orS. cerevisiae) at 30°C for 72 hr and then followed by lactobacilli fermentation (L. brevis orL. fermentum) at 30°C for 72 h more resulted in a significant reduction in phytic acid and polyphenol content of pearl millet flour. Fermentation byS. diastaticus andL. brevis combination almost eliminated phytic acid from pearl millet flour. The combinations ofS. diastaticus with both the lactobacilli reduced phytic acid more effectively than those ofS. cerevisiae. The products fermented byS. cerevisiae andL. brevis and byS. diastaticus andL. brevis combinations had the highest protein and starch digestibility (in vitro).  相似文献   

3.
The effects of different domestic processing and cooking methods on starch digestibility (in vitro) and protein digestibility (in vitro) of four strains of amphidiploids (black gram×mung bean) were investigated. An increase of 35 to 48% and 22 to 25% was observed in starch digestibility and protein digestibility, respectively, when the seed of amphidiploids were soaked for 18 h. Cooking (both of unsoaked and soaked seeds) and germination improved significantly the starch digestibility and protein digestibility of all the varieties.  相似文献   

4.
Germinated brown rice (GBR) recently has received renewed attention due to its enhanced nutritional value. Pasting properties and in vitro starch digestibility of GBR were examined before and after hydrothermal treatments. Steeping in water (30 °C, 24 h) raised the moisture content and germination percentage of brown rice. Pasting viscosity was substantially decreased but gelatinization temperatures and enthalpy were decreased only marginally by germination (30 °C, 48 h). However, annealing (50 °C, 24 h) and heat-moisture treatment (100 °C, 1 h at 30% moisture) after germination resulted in increased pasting viscosity and gelatinization temperatures. The hydrothermal treatments, however, induced browning reactions to darken the flour of GBR. The digestibility of starch in brown rice was increased by germination. The contents of rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) in the cooked brown rice were 47.3%, 40.8%, and 11.9%, respectively, but changed to 57.7%, 39.1%, and 3.2%, respectively upon germination. The hydrothermal treatments, however, decreased the digestibility of starch in GBR. The heat-moisture treatment decreased the RDS content in GBR near to that of native brown rice. The digestibility and physical properties of brown rice can be controlled by germination and hydrothermal treatments.  相似文献   

5.
Amino acid profiles, protein digestibility corrected aminoacid scores (PDCAAS), chemical scores, essential amino acid indexes, andcalculated biological values of control-cowpea flour (CCF), germinated cowpeaflour (GCF) prepared from cowpeas germinated at 25 °C for either24 h or 48 h and weaning foods prepared from cowpea flours weredetermined. Locally available rice, cowpea flour, banana-pumpkin slurry,and skim milk powder and sucrose in the ratio 35:35:15:15:5 were used to formulateweaning food containing not less than 15% protein. The ingredients werecooked into a slurry and oven-dried to produce flakes. The nutritional andsensory qualities of the weaning products were evaluated. Germination hadlittle effect on the amino acid profile of cowpeas. In vitro proteinquality and starch digestibility were improved in germinated cowpea flour. The PDCAAS of 24 h germinated cowpea flour (GCF) weaning food washigher (55.49%) than CCF-weaning food (46.74%). Vitamin A activityin 24 h GCF weaning food was higher than in CCF-weaning food. Invitro starch digestibilities of 24 h GCF and 48 h GCF-weaning foods werehigher than that of CCF weaning food. The 24 h GCF-weaning food which hada higher overall acceptability score by sensory panelist than 48 h GCFand CCF-weaning food is recommended for household consumption.  相似文献   

6.
Simple wet heat treatments like simple boiling (atmospheric pressure, 100 °C) and pressurized boiling (higher than 100 °C) reduced the polyphenol content of mature dark red seeds of cowpea (Vigna unguiculata (L.) Walp.) cultivar UPL Cp 3 by 61 to 80% and improved in vitro protein digestibility (IVPD) by 6 to 26%. Pressurized steaming (higher than 100 °C) removed 48 to 83% of the polyphenols but increased IVPD by only 1.1 to 4.2%. Dry heat as exemplified by roasting and microwave treatment inactivated 58 to 71% of the tannins but increased IVPD by only 1%. All the heat treatments were effective in removing/inactivating polyphenols though different responses were observed with the resulting in vitro protein digestibilities.  相似文献   

7.
Blue-green alga,Nostoc commune, contained moderate amounts of protein and iron. Itsin vitro protein digestibility was 43–50%. The soluble and ionic iron from the alga was extractable to some extent at pH 1.5 but was not detectable at pH 8.0. The digestion by protease did not affect the iron detection. Heat processing at 100 and 120°C failed to increase the digestibility and the content of available iron. The dietary fiber in the alga may be responsible for low protein digestion and low iron availability.  相似文献   

8.
Bran is a good source of dietary fibre, phytochemicals, and also protein, but highly insoluble and recalcitrant structure of bran hinders accessibility of these components for gastrointestinal digestion. In the present work, influence of bioprocessing on the microstructure and chemical properties of rye bran and wheat bread fortified with the rye bran were studied. In vitro protein digestibility, and release of short chain fatty acids (SCFA) and ferulic acid in a gut model were studied. Bioprocessing of rye bran was performed with subsequent treatments with cell-wall hydrolysing enzymes (40 °C, 4 h) and yeast fermentation (20 °C, 20 h). Bioprocessing of rye bran resulted in reduced total dietary fibre content, caused mainly by degradation of fructan and β-glucan, and increased soluble fibre content, caused mainly by solubilisation of arabinoxylans. Microscopic analysis revealed degradation of aleurone cell wall structure of the bioprocessed rye bran. Bioprocessing caused release of protein from aleurone cells, assessed as a larger content of soluble protein in bran and a higher hydrolysis rate in vitro. Bioprocessed bran had also faster SCFA formation and ferulic acid release in the colon fermentation in vitro as compared to native bran.  相似文献   

9.
The objective of this research was to ascertain the effects of soaking black grams (Cultivar AARI-5732)in different salt solutions at different temperatures and different timeperiods, and different methods of cooking on the tannin content and proteindigestibility. Tannin content of black grams was reduced to variousextents by soaking at 30° and 100 °C for different timeperiods. However, soaking at 100 °C increased the rate ofextraction and reduced the extraction time of tannins. Soaking black gramsin water at 100 °C reduced tannins by 22.14% in 45 minuteswhereas about 2.5 times more tannin was reduced after soaking in sodiumbicarbonate solution with or without sodium chloride. Maximumimprovement in protein digestibility was also observed after soaking blackgrams in sodium bicarbonate solution. Tannin contents were furtherreduced along with improvement in protein digestibility as a result ofcooking.  相似文献   

10.
Mature dark red seeds of cowpea (Vigna unguiculata (L.) Walp.) UPL Cp 3, were subjected to several soaking treatments to remove their polyphenols. Soaking in water at room temperature for 8 and 24 h resulted in 17% and 21% loss of assayable polyphenols, respectively. Dilute solutions of alkali (Na2CO3, NaHCO3, NH4OH and KOH) and acid (CH3 COOH, HCl and H2 SO4) were more effective in removing polyphenols up to 88% than higher concentrations of alkali and acid solutions.Vinegar (0.005–0.65 M CH3 COOH) decreased polyphenols from 55 to 62% with a 6 to 14% improvement in in vitro protein digestibility (IVPD). Commercial lime (65% CaO) removed polyphenols from seeds soaked for 8 to 24 h by 70% with 2 to 10% increase in in vitro protein digestibility. Ash removed 40 to 60% of the polyphenols after 8 and 24 h of soaking with an increase in IVPD of 7 to 13%. Total polyphenols were significantly correlated (+0.92**) with protein precipitable polyphenols (condensed tannins).  相似文献   

11.
Rabadi fermentation of barley flour-buttermilk mixture (fresh and autoclaved) at 30, 35 and 40°C for 6, 12, 18, 24 and 48 h lowered pH, enhanced titratable acidity and did not change fat and total mineral (Ca, Fe, Cu, Zn, Mn and P) content. Protein content of fermented fresh as well as autoclaved barley flour-buttermilk mixture either decreased or remained unchanged.Rabadi prepared from both types of barley flour at different temperatures and time periods was acceptable; but that which was fermented at 40°C for 48 h was less acceptable in terms of taste.  相似文献   

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.
Solid state fermentation (SSF) represents a technological alternative for a great variety of cereals and legumes, orcombination of them, to improve their nutritional quality and to obtain edible products with palatable sensorial characteristics. The objective of this work was to find the best conditions of fermentation temperature and time to obtain tempeh from hardened chickpeas (Cicer arietinum L.) applying SSF. Response surface methodology(RSM) was applied over three response variables (phytic acid, in vitro protein digestibility and available lysine) to find best conditions of fermentation to carry out the process. A central composite experimental design with two factors [X1 = temperature (31–36 °C) and X2 = time (48–72 h)] in five levels (2 factorials,2 axial, I central) was used. Spores from Rhizopus stolonifer were suspended in distilled water (1 ×106 spores/mL) and used as starter. According to regression models, minimum and maximum levels of the response variables were 1.24–2.66 mg phytic acid/g ofsample DM, 77.6–83.5% in vitro protein digestibility and2.18–4.63 g available lysine/16 g N. The superposition ofcontour plots of each one of the response variables allowedresearchers to find, graphically, the best conditions for the SSF process: 35.8 °C for 42.7 h.  相似文献   

14.
A Box-Behnken experimental design and response surface methodology were employed to optimize the pretreatment parameters of a formic/acetic acid delignification treatment of Miscanthus × giganteus for enzymatic hydrolysis. The effects of three independent variables, namely cooking time (1, 2 and 3 h), formic acid/acetic acid/water ratio (20/60/20, 30/50/20 and 40/40/20) and temperature (80, 90 and 107 °C) on pulp yield, residual Klason lignin content, concentration of degradation products (furfural and hydroxymethylfurfural) in the black liquor, and enzymatic digestibility of the pulps were investigated. The major parameter influencing was the temperature for pulp yield, delignification degree, furfural production and enzymatic digestibility. According to the response surface analysis the optimum conditions predicted for a maximum enzymatic digestibility of the glucan (75.3%) would be obtained using a cooking time of 3 h, at 107 °C and with a formic acid/acetic acid/water ratio of 40/40/20%. Glucan digestibility was highly dependent on the delignification degree.  相似文献   

15.
The nutritional quality of wild and cultivated species ofVigna has been evaluated. Wild species showed significantly higher protein content (P<0.01), antitryptic activity (P<0.005) and tannin content (P<0.025) and significantly lower protein digestibility (P<0.005). No significant differences were found with regard to protein quality, measured as chemical score corrected by the digestibility; sulphur amino acids turned out to be limiting in both groups. In addition no correlations were found between sulphur amino acids and protein levels, or between sulphur amino acid and trypsin inhibitor levels.Selected lines showed an improvement from the nutritional point of view linked to lower antitryptic factors and tannin content, which may give rise to a decreased resistance to pests. For all the properties considered, whether physical or biochemical, wild samples presented wider variations and the types considered most primitive were those that differed most from the cultivated ones, whose properties were altogether more consistent. In vitro protein digestibility turned out to be a useful parameter in evaluating wild and improved samples.IITA (International Institute of Tropical Agriculture) fellowship recipients.  相似文献   

16.
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   

17.
Amino acid composition, protein digestibility, calculated protein efficiency ratio (C-PER and DC-PER), chemical scores and water-soluble vitamin content of cowpea seeds germinated at 25°C or 30°C for 24h were determined. Also, the effect of processing steps (heated-air drying, decortication and cooking) on these parameters were examined. Germination had little effect on amino acid profile of cowpeas. In vitro protein digestibility was not improved significantly by germination nor by decortication but was improved by cooking. C-PER and DC-PER ranged from 1.95 to 2.21 and from 1.63 to 1.82, respectively. DC-PER compared well withreported rat PER of cowpea products and seemed more sensitive than C-PER. Based on whole egg values, chemical scores ranged from 37.7 to 45.8% (mean±SD; 42.2±2.4%). Germination increased the contents of niacin, thiamin and riboflavin significantly. Decortication resulted in up to 30% loss in niacin while thiamin content was reduced 41% by cooking.  相似文献   

18.
This study aimed to determine the fermentation characteristics, nutrient composition and in vitro digestibility of desert wormwood (DW, Artemisia desertorum Spreng.) silage as the sole ingredient, or mixed with high‐moisture maize (corn) straw (HMCS). Desert wormwood and HMCS were harvested and chopped (1–2 cm) then ensiled in laboratory silos (25 cm high with an internal diameter of 7·6 cm) at a density of 550 g L?1 at room temperature for 60 days. The proportions of DW in the DW/HMCS mixtures were 1, 0·75, 0·50, 0·25 and 0, based on fresh weight. The silages were analysed for fermentation characteristics, nutrient composition and in vitro digestibility. Desert wormwood ensiled with HMCS had lower pH and acetic acid concentration and higher lactic acid concentration as the proportion of DW decreased. As the proportion of DW decreased, the crude protein concentration and the in vitro digestibility of dry matter increased and the concentrations of neutral detergent fibre, acid detergent fibre and acid detergent lignin decreased. This study has indicated that mixing HMCS with DW can improve the fermentation quality and nutrient composition of these silage mixtures.  相似文献   

19.
In vitro ruminal fermentation techniques rely on the availability of fistulated ruminants for rumen fluid (RF), a major constraint for resource‐poor institutions. An alternative would be to use faecal microbes. This study was therefore designed to compare the potency of fresh bovine faeces against RF as sources of microbial inocula for fermenting six contrasting tropical forages using the Tilley and Terry (Journal of British Grassland Society, 18 , 104–111) technique. Faecal inocula were prepared at concentrations of 250 g (Faec250), 300 g (Faec300), 350 g (Faec350), 400 g (Faec400) and 450 g (Faec450) fresh cow faeces per litre bicarbonate buffer. In vitro organic matter digestibility (IVOMD) increased with increasing concentration of faeces at 12‐, 24‐ and 48‐h incubation intervals. All faecal inocula except Faec450 had lower potency when compared with RF at all incubation intervals. Digestibility of forage substrates with Faec450 (533 ± 23 g kg?1 DM IVOMD) was comparable to RF (566 ± 5 g kg?1 DM IVOMD) after 48‐h incubation. Faec450 showed greater potency on more fibrous and low‐protein substrates than RF. The coefficient of determination of the regression models for predicting 12‐, 24‐ and 48‐h RF IVOMD from Faec450 were 0·914, 0·75 and 0·756 respectively. It was concluded that inocula prepared from 450 g cow faeces demonstrated great potential as a substitute and predictor for RF in 48‐h IVOMD assays of tropical forages.  相似文献   

20.
The effects of rate of inorganic nitrogen (N) fertilization (0, 80 or 160 kg N ha?1 per regrowth), season of harvest (regrowths 1, 2 and 3) and perennial ryegrass (Lolium perenne L.) cultivar [classified as having either a normal or elevated water soluble carbohydrate (WSC) concentration genotype] on in vitro gas production and digestibility were assessed. Increased N fertilizer application significantly decreased total gas production (TGP), methane (CH4) production and organic matter digestibility (OMD). The results suggest that the decreases in TGP and CH4 production were associated with a restriction in organic matter (OM) fermentation and an altered crude protein (CP) to structural carbohydrate ratio rather than a modification in the stoichiometry of fermentation. Season of harvest only significantly (P < 0·05) altered in vitro OMD and CH4 production at 8 h, despite altering the chemical composition of the herbage. Cultivar effects on all measured in vitro parameters were not significant presumably because the elevated WSC concentration trait was not expressed strongly in the study.  相似文献   

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