The aim of this research was to find and assay phytochemical compounds and various biological macromolecules of the tender stems of Dioscorea praehensilis benth and evaluate their antioxidant activity and to compare t...The aim of this research was to find and assay phytochemical compounds and various biological macromolecules of the tender stems of Dioscorea praehensilis benth and evaluate their antioxidant activity and to compare the content of oxalates and cyanogenetic glucosides between raw and cooked tender stems.The plant collection and identification,phytochemical evaluation:phytochemical screening,preliminary(qualitative)analyses and in vitro assays.Phytochemical screening was performed by qualitative methods.The estimation of the content of secondary metabolites was evaluated by spectrophotometry-UV.Antioxidant activity was evaluated using the ABTS and DPPH assays and preliminary composition by the gravimetric method.The results obtained show that the stems of Dioscorea praehensilis are devoid of certain important chemical groups,the flavonoids were not detected and they were rich in total polyphenols(17.22±0.16),tannins(19.32±0.52)and anthocyanins(25.22±0.04).Our extracts showed a lower antioxidant activity than that of positive controls.The samples are rich in carbohydrates and fiber,with low levels of proteins,lipids and ash.Dioscorea praehensilis has a high toxicity in HCN,but after a good cooking of about 1 hour,99.97%of the cyanide are eliminated and does not have many oxalates.The results obtained show that Dioscorea praehensilis has a high dietary value and can therefore be used as a nutritive food.展开更多
Background: Corn and soybean meal(SBM) are two of the most common feed ingredients used in pig feeds.However, a variety of antinutritional factors(ANFs) present in corn and SBM can interfere with the bioavailability o...Background: Corn and soybean meal(SBM) are two of the most common feed ingredients used in pig feeds.However, a variety of antinutritional factors(ANFs) present in corn and SBM can interfere with the bioavailability of nutrients and have negative health effects on the pigs. In the present study, two-stage fermentation using Bacillus subtilis followed by Enterococcus faecium was carried out to degrade ANFs and improve the nutritional quality of corn and SBM mixed feed. Furthermore, the microbial composition and in vitro nutrient digestibility of inoculated mixed feed were determined and compared those of the uninoculated controls.Results: During the fermentation process, B. subtilis and lactic acid bacteria(LAB) were the main dominant bacteria in the solid-state fermented inoculated feed, and fermentation produced a large amount of lactic acid(170 mmo L/kg),which resulted in a lower pH(5.0 vs. 6.4) than the fermented uninoculated feed. The amounts of soybean antigenic proteins(β-conglycinin and glycinin) in mixed feed were significantly decreased after first-stage fermentation with B. subtilis. Inoculated mixed feed following two-stage fermentation contained greater concentratioin of crude protein(CP), ash and total phosphorus(P) compared to uninoculated feed, whereas the concentrations of neutral detergent fiber(NDF), hemicellulose and phytate P in fermendted inoculated feed declined(P < 0.05) by 38%, 53%, and 46%,respectively. Notably, the content of trichloroacetic acid soluble protein(TCA-SP), particularly that of small peptides and free amino acids(AA), increased 6.5 fold following two-stage fermentation. There was no difference in the total AA content between fermented inoculated and uninoculated feed. However, aromatic AAs(Phe and Tyr) and Lys in inoculated feed increased, and some polar AAs, including Arg, Asp, and Glu, decreased compared with the uninoculated feed. In vitro dry matter and CP digestibility of inoculated feed improved(P < 0.05) compared with the uninoculated feed.Conclusions: Our results suggest that two-stage fermentation using B. subtilis followed by E. faecium is an effective approach to improve the quality of corn-soybean meal mixed feed.展开更多
Anti-nutritional studies on cowpea (Vigna ungiculata L.) seeds as whole cowpea flour (WCF), dehulled cowpea flour (DCF), dehulled defatted cowpea flour (DDCF) and protein isolates obtained from DDCF by isoelectric (CP...Anti-nutritional studies on cowpea (Vigna ungiculata L.) seeds as whole cowpea flour (WCF), dehulled cowpea flour (DCF), dehulled defatted cowpea flour (DDCF) and protein isolates obtained from DDCF by isoelectric (CPIA) and micellization (CPIB) precipitation. The protein content of WCF and DDCF were 22.3% and 26.75% respectively, while CPIA and CPIB showed 75% and 76% respectively. The abundant minerals in WCF and DCF were calcium (32.38 - 33.61 mg/100 g);potassium (29.25 - 24.99 mg/100 g);and sodium (1.76 - 1.00 mg/100 g). The least abundant minerals were iron (0.004 - 0.013 mg/100 g);copper (0.04 - 0.25 mg/100 g);manganese (0.18 - 0.30 mg/100 g) and zinc (0.26 - 1.22 mg/100 g);respectively. Trypsin inhibitor activity for WCF, CPIA and CPIB was found 16,640 TIU/g, 4293 TIU/g and 4290 TIU/g respectively. Condensed tannins in RCF and DDCF were found 0.003% and 0.004% respectively while phytic acid content 0.8% and 1.17% respectively, no phytic acid and tannins were observed in protein isolates. Cowpea flour was also similar to other edible grain legumes in content of anti-nutritional factors;appropriate processing methods improved cowpea nutritive value and significantly reduced the levels of anti-nutritional factors.展开更多
文摘The aim of this research was to find and assay phytochemical compounds and various biological macromolecules of the tender stems of Dioscorea praehensilis benth and evaluate their antioxidant activity and to compare the content of oxalates and cyanogenetic glucosides between raw and cooked tender stems.The plant collection and identification,phytochemical evaluation:phytochemical screening,preliminary(qualitative)analyses and in vitro assays.Phytochemical screening was performed by qualitative methods.The estimation of the content of secondary metabolites was evaluated by spectrophotometry-UV.Antioxidant activity was evaluated using the ABTS and DPPH assays and preliminary composition by the gravimetric method.The results obtained show that the stems of Dioscorea praehensilis are devoid of certain important chemical groups,the flavonoids were not detected and they were rich in total polyphenols(17.22±0.16),tannins(19.32±0.52)and anthocyanins(25.22±0.04).Our extracts showed a lower antioxidant activity than that of positive controls.The samples are rich in carbohydrates and fiber,with low levels of proteins,lipids and ash.Dioscorea praehensilis has a high toxicity in HCN,but after a good cooking of about 1 hour,99.97%of the cyanide are eliminated and does not have many oxalates.The results obtained show that Dioscorea praehensilis has a high dietary value and can therefore be used as a nutritive food.
基金supported by a China Pig Modern Industrial Technology System Grant(CARS-36),the ChinaZhejiang province Postdoctoral Science Foundation(518000-X91604,518000-X81601)
文摘Background: Corn and soybean meal(SBM) are two of the most common feed ingredients used in pig feeds.However, a variety of antinutritional factors(ANFs) present in corn and SBM can interfere with the bioavailability of nutrients and have negative health effects on the pigs. In the present study, two-stage fermentation using Bacillus subtilis followed by Enterococcus faecium was carried out to degrade ANFs and improve the nutritional quality of corn and SBM mixed feed. Furthermore, the microbial composition and in vitro nutrient digestibility of inoculated mixed feed were determined and compared those of the uninoculated controls.Results: During the fermentation process, B. subtilis and lactic acid bacteria(LAB) were the main dominant bacteria in the solid-state fermented inoculated feed, and fermentation produced a large amount of lactic acid(170 mmo L/kg),which resulted in a lower pH(5.0 vs. 6.4) than the fermented uninoculated feed. The amounts of soybean antigenic proteins(β-conglycinin and glycinin) in mixed feed were significantly decreased after first-stage fermentation with B. subtilis. Inoculated mixed feed following two-stage fermentation contained greater concentratioin of crude protein(CP), ash and total phosphorus(P) compared to uninoculated feed, whereas the concentrations of neutral detergent fiber(NDF), hemicellulose and phytate P in fermendted inoculated feed declined(P < 0.05) by 38%, 53%, and 46%,respectively. Notably, the content of trichloroacetic acid soluble protein(TCA-SP), particularly that of small peptides and free amino acids(AA), increased 6.5 fold following two-stage fermentation. There was no difference in the total AA content between fermented inoculated and uninoculated feed. However, aromatic AAs(Phe and Tyr) and Lys in inoculated feed increased, and some polar AAs, including Arg, Asp, and Glu, decreased compared with the uninoculated feed. In vitro dry matter and CP digestibility of inoculated feed improved(P < 0.05) compared with the uninoculated feed.Conclusions: Our results suggest that two-stage fermentation using B. subtilis followed by E. faecium is an effective approach to improve the quality of corn-soybean meal mixed feed.
文摘Anti-nutritional studies on cowpea (Vigna ungiculata L.) seeds as whole cowpea flour (WCF), dehulled cowpea flour (DCF), dehulled defatted cowpea flour (DDCF) and protein isolates obtained from DDCF by isoelectric (CPIA) and micellization (CPIB) precipitation. The protein content of WCF and DDCF were 22.3% and 26.75% respectively, while CPIA and CPIB showed 75% and 76% respectively. The abundant minerals in WCF and DCF were calcium (32.38 - 33.61 mg/100 g);potassium (29.25 - 24.99 mg/100 g);and sodium (1.76 - 1.00 mg/100 g). The least abundant minerals were iron (0.004 - 0.013 mg/100 g);copper (0.04 - 0.25 mg/100 g);manganese (0.18 - 0.30 mg/100 g) and zinc (0.26 - 1.22 mg/100 g);respectively. Trypsin inhibitor activity for WCF, CPIA and CPIB was found 16,640 TIU/g, 4293 TIU/g and 4290 TIU/g respectively. Condensed tannins in RCF and DDCF were found 0.003% and 0.004% respectively while phytic acid content 0.8% and 1.17% respectively, no phytic acid and tannins were observed in protein isolates. Cowpea flour was also similar to other edible grain legumes in content of anti-nutritional factors;appropriate processing methods improved cowpea nutritive value and significantly reduced the levels of anti-nutritional factors.
