鸭蛋卵清蛋白多肽的酶解条件优化及生物活性

Optimization of Enzymatic Hydrolysis Conditions of Ovalbumin from Duck Eggs and Biological Activity of the Resulting Peptides

通过正交试验探究了鸭蛋卵清蛋白的酶解条件,以水解度为指标确定了最佳酶解条件:选用木瓜蛋白酶,加酶量为4.5×104 U/(g·min),酶解时间5.5 h,酶解温度55℃,酶解pH 6.40,最佳条件下的水解度为27.91%。采用高效液相色谱法确定了鸭蛋卵清蛋白酶解产物(Hydrolysate of albumin in duck egg,HD)的相对分子质量分布范围:0<Mw<300占33.71%,300<Mw<450占29.21%,450<Mw<1450占20.42%,1450<Mw<6500占0.49%,6500<Mw<12500占5.05%,Mw>12500占11.12%。再对其生物活性进行探究,在HD的免疫活性实验中,250μg/mL的HD能显著提高RAW 264.7细胞中NO、细胞因子TNF-α和IL-6的分泌量(P<0.05),1000μg/mL的HD对AAPH诱导的红细胞溶血抑制率为(53.95±1.82)%,具有显著性(P<0.05),对DPPH、ABTS+·自由基清除率分别为(31.92±0.54)%、(86.46±2.12)%,ORAC值为0.3574μmol/mg,表明HD也具有很好的体外抗氧化活性。

The enzymatic hydrolysis conditions of ovalbumin from duck eggs were investigated through orthogonal test,and the optimal hydrolysis conditions were determined by taking the hydrolysis degree as the index:the amount of papain 4.5×104 U/(g·min),hydrolysis time 5.5 h,temperature 55℃,pH 6.40.With the optimal conditions,the hydrolysis degree was 27.91%.The molecular weight distribution ranges of hydrolysate were determined by HPLC:0<Mw<300(33.71%),300<Mw<450(29.21%),450<Mw<1450(20.42%),1450<Mw<6500(0.49%),6500<Mw<12500(5.05%),and Mw>12500(11.12%).Its biological activity was further studied.Hydrolysate(250μg/mL)significantly increased the secretion of NO,cytokines TNF-αand IL-6 in RAW 264.7 cells(P<0.05),showing a certain immunological activity.Meanwhile,the inhibition rate of 1000μg/mL hydrolysate for AAPH induced erythrocyte hemolysis was(53.95±1.82)%(P<0.05),the scavenging rates of DPPH and ABTS+·free radical were(31.92±0.54)%and(86.46±2.12)%,and the ORAC value was 0.3574μmol/mg,indicating that the hydrolysate also had a good antioxidant activity in vitro.