It was studied that the technique of the enzymatic hydrolysis of walnut to prepare the peptide with low-molecular weights, antioxidant activities of which were also determined.The optimum hydrolysis conditions ( pH8.5,temperature 50℃, the ratio of enzyme concentration to substrate concentration [E]/[S]= 3: 100, substrate concentration[S]= 3.5g/100mL, time 5h) were obtained through single factor test and orthogonal test.Walnut peptides were isolated into 3 parts by ultrafiltration membranes with 3kDa MWCO( Molecular Weight Cutoff), 10kDa MWCO respectively.The antioxidant activities of different parts of walnut peptides were studied,which revealed that the part of walnut peptides with molecular weight ＜3kDa showed the best antioxidant activities.%利用木瓜蛋白酶酶解核桃分离蛋白制备小分子活性肽,并研究了不同分子量段核桃小分子肽的抗氧化性能.通过单因素实验和正交实验,确定了木瓜蛋白酶制备抗氧化肽的最佳酶解条件为:pH8.5,温度50℃,酶与底物浓度之比[E]/[S]=3:100,底物浓度[S]=3.5g/100mL,酶解时间5 h.用截留分子量分别为3kDa和10kDa的超滤膜将核桃粗肽液分离成＜3kDa,3～10kDa及＞10kDa 3个分子量段,并对不同分子量段核桃多肤的抗氧化性进行了研究,结果表明,分子量＜3kDa的核桃多肤的抗氧化性大于其他两个分子量段.
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