Herein,a novel method for fl uorometric detection of soybean trypsin inhibitor(SBTI)activity based on a water-soluble poly(diphenylacetylene)derivative was reported.Fluorescence quenching of the polymer via p-nitroani...Herein,a novel method for fl uorometric detection of soybean trypsin inhibitor(SBTI)activity based on a water-soluble poly(diphenylacetylene)derivative was reported.Fluorescence quenching of the polymer via p-nitroaniline,produced from the trypsin-catalyzed decomposition of N-benzoyl-DL-arginine-4-nitroanilide hydrochloride(L-BAPA),was well described using the Stern-Volmer equation.SBTI activity was quantitatively assessed based on changes in the fl uorescence intensity of the polymer.This strategy has several advantages,such as high sensitivity and ease of operation.Moreover,its applicability to other biochemical analyses is promising.展开更多
By 30% - 60% (NH4)(2)SO4 fractional precipitation, anion-exchange chromatography on DEAE-Sepharose CL-6B, gel filtration on Sephacryl S-200 and anion-exchange chromatography on Waters AP-1 column (Protein(PM)-Pak DEAE...By 30% - 60% (NH4)(2)SO4 fractional precipitation, anion-exchange chromatography on DEAE-Sepharose CL-6B, gel filtration on Sephacryl S-200 and anion-exchange chromatography on Waters AP-1 column (Protein(PM)-Pak DEAE 15HR), a proteinase which can inactivate soybean trypsin inhibitor (STI) was purified from mung bean ( Vigna rabiata (L.) Wilezek) sprouts. Its molecular weight was estimated to be 29.8 kD by SDS-PAGE, and its K-m and V-max for STI were 769.2 N-alpha -benzoyl-L-arginine ethyl ester BAEE/mL and 115.3 BAEE . mL(-1) . min(-1) respectively. This proteinase was stable at temperatures lower than 50 degreesC and pH 6.5 - 8.5, and 90.91% STI activity of defatted soybean powder was inactivated by this preparation, with proteolytic activity 5 000 BAEE/mL at 50 degreesC and pH 8.0 in 4 h.展开更多
The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on ph...The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on phytic acid, crude protein, crude fat, and amino acid profile. Response surface methodology （RSM） with Box-Behnken design was used to optimize SSF. The optimal conditions derived from RSM for L. brevis fermentation were： pH=5. 1; inoculum size=10%; duration=72 h; substrate to water ratio=1.5. The minimum content of trypsin inhibitors was 6.4 mg g^-1 dry matter. The optimal conditions derived from RSM for A. oryzae fermentation were： substrate to water ratio= 0.8 1; inoculum size=4%; duration=120 h. The minimum content of trypsin inhibitors was 1.6 mg g^-1 dry matter. Both L. brevis and A. oryzae decreased trypsin inhibitors dramatically （57.1 and 89.2% respectively）. L. brevis fermentation did not affect phytic acid （0.4%） and crude fat （5.2%） considerably, whereas A. oryzae fermentation degraded phytic acid （34.8%） and crude fat （22.0%） contents to a certain extent. Crude protein content was increased after both fermentation （6.4 and 12.9% for L. brevis and A. oryzae respectively）. Urease activity was reduced greatly （83.3 and 58.3% for L. brevis and A. oryzae respectively）. In conclusion, SSF with A. oryzae and L. brevis reduced trypsin inhibitor content and modified major macronutrients in soybean meal.展开更多
Hebei Province is one of the main distribution areas growing wild soybean( Glycine soja ) in China. In this study, 461 seed samples,collected from 18 natural populations in this province, were used to electrophoretica...Hebei Province is one of the main distribution areas growing wild soybean( Glycine soja ) in China. In this study, 461 seed samples,collected from 18 natural populations in this province, were used to electrophoretically observe the change in forms and their frequencies of the Kunitz trypsin inhibitor protein (KTI)in individual populations and geographical areas. Allelic frequencies accounted for 85% for Tia and 15% for Tib in the total samples. Twelve populations examined were polymorphic at the KTI locus, accounting for over 50% in the populations investigated. Four populations, 22% of all the populations, were found to have natural cross-pollination with varied heterozygote rates of 3% -5.5%, and the average was 1% in the total sampies. Geographically, the mean Tib frequency in the north areas was higher than in the south, and higher in the mountainous area than in the plain areas. The populations in a lake ecological environment (Baiyangdian Lake) were almost monomorphic. No obvious relationship between the frequency and the geographical distance was observed. In addition, we first found a mutation for the absence of the KTI in wild soybean.展开更多
A significant reduction of trypsin inhibitory activity by selected bacterial proteolytic enzymes was demonstrated in vitro.Two trials were conducted to examine the capacity of the tested enzymes to inactivate soybean ...A significant reduction of trypsin inhibitory activity by selected bacterial proteolytic enzymes was demonstrated in vitro.Two trials were conducted to examine the capacity of the tested enzymes to inactivate soybean ANFs in vivo.In trial I,twenty four piglets weaned at four weeks of age were assigned in replicate groups of 4 piglets per pen to one of three dietary treatments:(1)control;(2)Enzyme 1 supplemented(E 1);(3)Enzyme 2 supplemented (E 2).In trial II,twenty piglets weaned at five weeks of age were alloted to five treatment diets:(1)contro,l:(2)0.1% P4 supplemented;(3)0.5% P4 supplemented;(4)0.1% P7 supplemented;(5)0.5% P7 supplemented.The optimum pH for hydrolysis was 8 for E ,9 11 for E 2,8.5 for P4 and nuctral for P7.After 17 days of the trial,daily gain of piglets on enzymes E 1 and E 2 was 36% and 18% more than that in the control group,although the difference was not significant.The animals on the treated groups had a tendency to have lighter heart(7.8 and 5.9%),spleen(11.1 and 7.4%) and pancreas(16.7 and 12.5% for E 1 and E 2 respectively)in relation to empty body weight than those in the control.The small intestine of pigs on the treated groups was significantly lighter(18.9 for E 1 and 7.7% for E 2) than that in the control(P<0.05).The stomach (26.4 and 24%,p=0.198) and cecum(21.9 and 9.4%,p=0.114) also showed the same pattern.The growth depression was attributed to reduced feed intake caused by antinutritional factors in soybeans.It is concluded that supplements of proteolytic enzymes E 1 or E 2 had a positive effect on growth and efficiency and caused much less reaction in the gut as manifested by the weight of the tract and of its accessory organs.Dietary saupplements of P4 or P7 had no significant effect on growth,but reduced reaction of soybean antinutritional factors in the gut,especialy P4 in dose of 0.5%.The growth depression was attributed to low feed intake caused by antinutritional factors in soybeans.展开更多
In this study,a low-capacity single-screw cooking extruder for the manufacture of expanded snacks was designed based on theoretical models and guided operating data and practices of existing cooking extruders.Construc...In this study,a low-capacity single-screw cooking extruder for the manufacture of expanded snacks was designed based on theoretical models and guided operating data and practices of existing cooking extruders.Construction was carried out using locally available engineering materials in modest machine shops satisfying sanitary design criteria and tested using blends of cassava and defatted soybean flour.The extruder developed has throughput,screw speed,barrel diameter,length-to-diameter ratio and power requirement of 13.0 kg/h,200 rpm,40 mm,12 and 1.908 kW,respectively.The cost of the extruder developed was estimated N650,000 in 2016.Extrudates had expansion ratio and trypsin inhibitor reduction which ranged from 1.82 to 2.98 and 61.07%to 87.93%,respectively,across all treatments.This study demonstrates that a low-capacity and affordable experimental single-screw extruder can be designed and built domestically which can be scaled-up for pilot and industrial applications for the production of expanded snacks.展开更多
基金The authors appreciate the support from the Zhe-jiang Province Lingyan Key R&D Project(No.2022C01177)the Zhejiang Administration for Market Regulation Eyas Program Cultiva-tion Project(No.CY2022355).
文摘Herein,a novel method for fl uorometric detection of soybean trypsin inhibitor(SBTI)activity based on a water-soluble poly(diphenylacetylene)derivative was reported.Fluorescence quenching of the polymer via p-nitroaniline,produced from the trypsin-catalyzed decomposition of N-benzoyl-DL-arginine-4-nitroanilide hydrochloride(L-BAPA),was well described using the Stern-Volmer equation.SBTI activity was quantitatively assessed based on changes in the fl uorescence intensity of the polymer.This strategy has several advantages,such as high sensitivity and ease of operation.Moreover,its applicability to other biochemical analyses is promising.
文摘By 30% - 60% (NH4)(2)SO4 fractional precipitation, anion-exchange chromatography on DEAE-Sepharose CL-6B, gel filtration on Sephacryl S-200 and anion-exchange chromatography on Waters AP-1 column (Protein(PM)-Pak DEAE 15HR), a proteinase which can inactivate soybean trypsin inhibitor (STI) was purified from mung bean ( Vigna rabiata (L.) Wilezek) sprouts. Its molecular weight was estimated to be 29.8 kD by SDS-PAGE, and its K-m and V-max for STI were 769.2 N-alpha -benzoyl-L-arginine ethyl ester BAEE/mL and 115.3 BAEE . mL(-1) . min(-1) respectively. This proteinase was stable at temperatures lower than 50 degreesC and pH 6.5 - 8.5, and 90.91% STI activity of defatted soybean powder was inactivated by this preparation, with proteolytic activity 5 000 BAEE/mL at 50 degreesC and pH 8.0 in 4 h.
基金supported by a research project of the Science and Technology Key Group in Zhejiang Provincethe research projects from the Science and Technology Department of Zhejiang Province,China (2009C12068)
文摘The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on phytic acid, crude protein, crude fat, and amino acid profile. Response surface methodology （RSM） with Box-Behnken design was used to optimize SSF. The optimal conditions derived from RSM for L. brevis fermentation were： pH=5. 1; inoculum size=10%; duration=72 h; substrate to water ratio=1.5. The minimum content of trypsin inhibitors was 6.4 mg g^-1 dry matter. The optimal conditions derived from RSM for A. oryzae fermentation were： substrate to water ratio= 0.8 1; inoculum size=4%; duration=120 h. The minimum content of trypsin inhibitors was 1.6 mg g^-1 dry matter. Both L. brevis and A. oryzae decreased trypsin inhibitors dramatically （57.1 and 89.2% respectively）. L. brevis fermentation did not affect phytic acid （0.4%） and crude fat （5.2%） considerably, whereas A. oryzae fermentation degraded phytic acid （34.8%） and crude fat （22.0%） contents to a certain extent. Crude protein content was increased after both fermentation （6.4 and 12.9% for L. brevis and A. oryzae respectively）. Urease activity was reduced greatly （83.3 and 58.3% for L. brevis and A. oryzae respectively）. In conclusion, SSF with A. oryzae and L. brevis reduced trypsin inhibitor content and modified major macronutrients in soybean meal.
文摘Hebei Province is one of the main distribution areas growing wild soybean( Glycine soja ) in China. In this study, 461 seed samples,collected from 18 natural populations in this province, were used to electrophoretically observe the change in forms and their frequencies of the Kunitz trypsin inhibitor protein (KTI)in individual populations and geographical areas. Allelic frequencies accounted for 85% for Tia and 15% for Tib in the total samples. Twelve populations examined were polymorphic at the KTI locus, accounting for over 50% in the populations investigated. Four populations, 22% of all the populations, were found to have natural cross-pollination with varied heterozygote rates of 3% -5.5%, and the average was 1% in the total sampies. Geographically, the mean Tib frequency in the north areas was higher than in the south, and higher in the mountainous area than in the plain areas. The populations in a lake ecological environment (Baiyangdian Lake) were almost monomorphic. No obvious relationship between the frequency and the geographical distance was observed. In addition, we first found a mutation for the absence of the KTI in wild soybean.
文摘A significant reduction of trypsin inhibitory activity by selected bacterial proteolytic enzymes was demonstrated in vitro.Two trials were conducted to examine the capacity of the tested enzymes to inactivate soybean ANFs in vivo.In trial I,twenty four piglets weaned at four weeks of age were assigned in replicate groups of 4 piglets per pen to one of three dietary treatments:(1)control;(2)Enzyme 1 supplemented(E 1);(3)Enzyme 2 supplemented (E 2).In trial II,twenty piglets weaned at five weeks of age were alloted to five treatment diets:(1)contro,l:(2)0.1% P4 supplemented;(3)0.5% P4 supplemented;(4)0.1% P7 supplemented;(5)0.5% P7 supplemented.The optimum pH for hydrolysis was 8 for E ,9 11 for E 2,8.5 for P4 and nuctral for P7.After 17 days of the trial,daily gain of piglets on enzymes E 1 and E 2 was 36% and 18% more than that in the control group,although the difference was not significant.The animals on the treated groups had a tendency to have lighter heart(7.8 and 5.9%),spleen(11.1 and 7.4%) and pancreas(16.7 and 12.5% for E 1 and E 2 respectively)in relation to empty body weight than those in the control.The small intestine of pigs on the treated groups was significantly lighter(18.9 for E 1 and 7.7% for E 2) than that in the control(P<0.05).The stomach (26.4 and 24%,p=0.198) and cecum(21.9 and 9.4%,p=0.114) also showed the same pattern.The growth depression was attributed to reduced feed intake caused by antinutritional factors in soybeans.It is concluded that supplements of proteolytic enzymes E 1 or E 2 had a positive effect on growth and efficiency and caused much less reaction in the gut as manifested by the weight of the tract and of its accessory organs.Dietary saupplements of P4 or P7 had no significant effect on growth,but reduced reaction of soybean antinutritional factors in the gut,especialy P4 in dose of 0.5%.The growth depression was attributed to low feed intake caused by antinutritional factors in soybeans.
文摘In this study,a low-capacity single-screw cooking extruder for the manufacture of expanded snacks was designed based on theoretical models and guided operating data and practices of existing cooking extruders.Construction was carried out using locally available engineering materials in modest machine shops satisfying sanitary design criteria and tested using blends of cassava and defatted soybean flour.The extruder developed has throughput,screw speed,barrel diameter,length-to-diameter ratio and power requirement of 13.0 kg/h,200 rpm,40 mm,12 and 1.908 kW,respectively.The cost of the extruder developed was estimated N650,000 in 2016.Extrudates had expansion ratio and trypsin inhibitor reduction which ranged from 1.82 to 2.98 and 61.07%to 87.93%,respectively,across all treatments.This study demonstrates that a low-capacity and affordable experimental single-screw extruder can be designed and built domestically which can be scaled-up for pilot and industrial applications for the production of expanded snacks.
