富含支链氨基酸汉麻分离蛋白酶解物制备及其品质评价

Preparation and quality evalutation of hemp protein isolate hydrolysate rich in branched amino acids

以汉麻籽粕为原料,通过胃蛋白酶和风味蛋白酶分步酶解,辅助活性炭脱芳,制备富含支链氨基酸的汉麻分离蛋白酶解物,并以抗氧化性和溶解度评价其品质特性。结果表明:制备富含支链氨基酸的汉麻分离蛋白酶解物工艺中胃蛋白酶最佳酶解条件为料液比1∶5、酶添加量0.9%、酶解温度37℃、酶解pH 2.5、酶解时间5 h,风味蛋白酶最佳酶解条件为酶解温度50℃、酶添加量0.8%、酶解p H 7、酶解时间4 h;经两步酶解后得到的汉麻分离蛋白酶解物(E-HPI)水解度为(33.01±0.43)%、A280为0.321±0.002;与汉麻分离蛋白(HPI)相比,E-HPI溶解度得到极大改善,p H 7时其溶解度为(83.67±2.45)%。氨基酸分析结果显示,E-HPI支链氨基酸含量为23.37%,显著高于HPI中支链氨基酸含量。抗氧化研究结果显示,E-HPI的·OH清除率和DPPH·清除率相比HPI分别提高了1.15倍和1.58倍。

Taking hemp seed meal as raw material,hemp protein isolate hydrolysate rich in branched amino acids was prepared by two-step hydrolysis of pepsin and flavourzyme and dearomatication by activated carbon.The quality of hemp protein isolate hydrolysate was evaluated by antioxidant properties and solubility.The results showed that the optimal hydrolysis conditions of pepsin were obtained as follows:solid-liquid ratio 1∶5,amount of enzyme 0.9%,pH 2.5,enzymolysis temperature 37℃and enzymolysis time5 h.The optimal hydrolysis conditions of flavourzyme were obtained as follows:enzymolysis temperature50℃,amount of enzyme 0.8%,pH 7 and enzymolysis time 4 h.Under these conditions,the degree of hydrolysis and A280 were(33.01±0.43)%and 0.321±0.002,respectively.Compared with hemp protein isolate(HPI),the solubility of hemp protein isolate hydrolysate(E-HPI)was significantly improved and it was(83.67±2.45)%at pH 7.The content of branched amino acid of E-HPI was23.37%,significantly higher than that of HPI.The antioxidant results showed that the scavenging rates of E-HPI on·OH and DPPH·were 1.15 times and 1.58 times higher than that of HPI.