The capacity of five enzymes (P1-P5) to inactivate the trypsin inhibitory activity (TIA) and lectin in raw soybean (RS) and low temperature-extruded soybean (LTES) was examined. P1 is an acid fungal protease with pH o...The capacity of five enzymes (P1-P5) to inactivate the trypsin inhibitory activity (TIA) and lectin in raw soybean (RS) and low temperature-extruded soybean (LTES) was examined. P1 is an acid fungal protease with pH optimum of 5 and P2, P3, P4 and P5 are bacterial proteases with pH optima of 7, 10, 8 and 8 respectively. The results indicated that all enzymes could reduce TIA to a varying degree at their optimum pH. The sequence of effectiveness was P3>P4>P5>P1>P2. The most effective enzyme, P3, reduced TIA to 38% and chymotrypsim inhibitory activity (CIA) to 9% of the original values. After six hours incubation at 50℃, the lectin concentration of LTES and RS was reduced by 50 and 17% respectively by P3, and by 42 and 29% by P4. In the second study, the best enzymes, P3 and P4, were incubated with RS or LTEs at different doses of 0, 0.10, 0.50% or 1.00% (w/w), for periods of 1, 2, 3, 6 or 12 hours. After one hour incubation with P3 at 1.00%, TIA of RS was reduced from 36.60 to 13.30 mg·g -1 . The corresponding values for LTES were 24.50 and 1.90 mg·g -1 . When the incubation was extended to 12 hours, the remaining TIA was 0.90 for LTES and 1.20 mg·g -1 for RS. P4 was not as effective as P3 up to six-hour incubation, but after twelve hours it achieved a similar reduction in activity to that of P3. A kinetic analysis of data showed that the inactivation process of purified soyabean trypsin inhibitors by P3 followed first-order chemical kinetics (Ct=90.90 -0.0408t , r=0.99). The rate of denaturation was -0.0408 per minute. It is concluded that the use of selected enzymes for anti-nutritive factors (ANFs) is an exciting possibility, but still requires further development.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
文摘The capacity of five enzymes (P1-P5) to inactivate the trypsin inhibitory activity (TIA) and lectin in raw soybean (RS) and low temperature-extruded soybean (LTES) was examined. P1 is an acid fungal protease with pH optimum of 5 and P2, P3, P4 and P5 are bacterial proteases with pH optima of 7, 10, 8 and 8 respectively. The results indicated that all enzymes could reduce TIA to a varying degree at their optimum pH. The sequence of effectiveness was P3>P4>P5>P1>P2. The most effective enzyme, P3, reduced TIA to 38% and chymotrypsim inhibitory activity (CIA) to 9% of the original values. After six hours incubation at 50℃, the lectin concentration of LTES and RS was reduced by 50 and 17% respectively by P3, and by 42 and 29% by P4. In the second study, the best enzymes, P3 and P4, were incubated with RS or LTEs at different doses of 0, 0.10, 0.50% or 1.00% (w/w), for periods of 1, 2, 3, 6 or 12 hours. After one hour incubation with P3 at 1.00%, TIA of RS was reduced from 36.60 to 13.30 mg·g -1 . The corresponding values for LTES were 24.50 and 1.90 mg·g -1 . When the incubation was extended to 12 hours, the remaining TIA was 0.90 for LTES and 1.20 mg·g -1 for RS. P4 was not as effective as P3 up to six-hour incubation, but after twelve hours it achieved a similar reduction in activity to that of P3. A kinetic analysis of data showed that the inactivation process of purified soyabean trypsin inhibitors by P3 followed first-order chemical kinetics (Ct=90.90 -0.0408t , r=0.99). The rate of denaturation was -0.0408 per minute. It is concluded that the use of selected enzymes for anti-nutritive factors (ANFs) is an exciting possibility, but still requires further development.
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.
