【摘要】 该研究采用两步酶解法制备小龙虾副产物多肽,先用碱性蛋白酶水解提取小龙虾副产物中粗蛋白,利用单因素和正交试验确定粗蛋白的最佳制备条件:2%碱性蛋白酶,酶解2 h,料液比1∶20(g/mL),酶解温度55℃、pH8.5,虾副产物蛋白得率最高为64.32%;胰蛋白酶二次酶解虾副产物粗蛋白制备多肽,以蛋白水解度为标准,利用正交试验优化得到酶解制备多肽的工艺条件:2%胰蛋白酶、酶解4 h,料液比1∶15(g/mL),酶解温度37℃、pH8.0的条件下,虾副产物蛋白水解度为45.2%。二次酶解产物比一次酶解产物的总抗氧化能力强;Tricine-十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)图谱显示二次酶解多肽的分子质量主要集中在3.3 k Da以下;多肽中含有18种氨基酸,其中必需氨基酸占总氨基酸的64.36%。小龙虾副产物多肽可用于功能食品及调味品的开发。更多还原

【Abstract】 A two-step enzymatic hydrolysis method was used to extract the polypeptides from crayfish by-products. Alcalase was used to prepare the protein from crayfish by-products. Single-factor and orthogonal array design revealed that the optimal preparation efficiency parameters were 2% alcalase,hydrolysis time 2 h,1∶20(g/mL)solid/liquid ratio,pH8.5,and 55 ℃. The protein extraction efficiency using the optimized conditions was 64.32%.In the second step,the protein from crayfish by-products was hydrolyzed by trypsin to prepare polypeptides with proteolysis as the standard. The optimum conditions were 2% trypsin concentration,hydrolysis duration of 4 h,1∶15(g/mL)solid/liquid ratio,pH8.0,and 37 ℃. The protein hydrolysis degree was up to 45.2% under the optimized conditions. The total antioxidant capacity of secondary hydrolysates were stronger than the primary ones.Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the relative molecular weight of most secondary hydrolysates was below 3.3 kDa. The two-step enzymatic hydrolysis resulted in 18 amino acids in the polypeptides. Essential amino acids comprised 64.36% of the total amino acids. The polypeptides could be used in functional foods and condiments.更多还原