根据蛋白在水溶液、盐溶液、醇溶液及碱性溶液中的溶解性不同，从核桃粕中分离得到四类不同性质的蛋白组分：清蛋白、球蛋白、醇溶蛋白和谷蛋白，其中球蛋白和谷蛋白含量较高，分别为16.90%和71.40%。以脱脂脱酚粕、谷蛋白和球蛋白为原料，分别制备蛋白酶解液，以DPPH自由基清除率和蛋白质回收率为指标，对蛋白酶解工艺条件进行优化，探讨蛋白酶解液的分子量分布与抗氧化活性的关系。结果表明：在碱性蛋白酶、pH 8及酶解9 h的条件下，蛋白酶解液有较高的DPPH·清除率和蛋白回收率；脱脂脱酚核桃粕酶解液DPPH·清除率83.29%高于谷蛋白酶解液79.25%和球蛋白酶解液72.27%，蛋白回收率分别为69.83%、66.42%和73.71%。脱脂脱酚粕、谷蛋白和球蛋白酶解液以小分子肽居多，其中相对分子量≤1000的肽段分别占总量的42.73%、63.91%和55.10%，推测其抗氧化活性可能与小分子肽含量有关。

According to the solubility of protein in an aqueous solution, salt solution, alcoholic solution and alkaline solution, four types of different protein components were separated from walnut meal: albumin, globulin, gliadin and glutenin. Among which, the contents of globulin and glutenin were higher (16.90% and 71.40%, respectively). The defatted and dephenolated walnut meal, glutenin and globulin were used as raw materials to prepare the proteolytic solution, and the DPPH free radical scavenging rate and protein recovery rate were used as indices to optimize the proteolytic conditions and investigate the relationship between molecular weight distribution and antioxidant activity. The results showed that the enzymatic hydrolysate had higher DPPH· scavenging rate and protein recovery rate under the conditions: alkaline protease, pH 8, and enzymolysis time 9 h. The DPPH· scavenging rate for the enzymatic hydrolysate of the defatted and dephenolated walnut meal was higher (83.29%) than those of glutenin hydrolysate (79.25%), and globulin hydrolysate (72.27%), with their protein recovery rates being 69.83%, 66.42% and 73.71% respectively. The peptides in these protein hydrolysates were mostly small molecular peptides, and among which, those with molecular weights not more than 1000 accounted for 42.73% (hydrolysate of defatted walnut meal), 63.91% (hydrolysate of glutenin) and 55.10% (hydrolysate of globulin), respectively. It is speculated that their antioxidant activities may be related to the contents of small peptides.

“广东特支计划”科技青年拔尖人才项目（2014TQ01N645）；国家自然科学基金项目（31671804）；中央高校基本科研业务费项目（2017ZD079）；广州市产学研协同创新重大专项（201604020047）；广东省科技计划项目（2015B020230001）