将Plackett-Burman因素水平设计应用于碱性蛋白酶水解大豆分离蛋白,以研究大豆分离蛋白酶水解物的抗氧化活性.通过测定水解产物的亚铁还原能力来确定其抗氧化活性的强弱,以此确定最佳水解工艺条件 为:反应温度72℃,底物浓度9％,酶用量(E/S) 1％,pH 7.0,水解时间5h.采用最适水解工艺条件得到水解度为19.78％,制备的水解物亚铁还原能力为:987.13μmol·L-1.同时测定水解物抑制脂质过氧化的能力(TBARS法)以及对DPPH(二苯代苦味肼基)自由基的清除能力.研究表明,水解物具有较高的抗氧化活性,可以有效抑制脂质过氧化以及较好的清除DPPH自由基,其抗氧化活性虽然低于化学合成抗氧化剂,但明显高于未水解的蛋白质.%The factorial level design of Plackett-Burman was used to study soybean peptides obtained through hydrolyzing soybean isolated proteins by Alcalase, and then the antioxidant activities of soy isolate protein hydrolyzate was studied. The antioxidant activity of hydrolysate was detected by measuring its ferrous iron's reducing capacity, and the optimal hydrolysis conditions were as followings: reaction temperature of 72 ℃, substrate concentration of 9%, enzyme concentration of (E/S) 1%, pH 7.0, hydrolysis time 5 h. The hydrolysis degree obtained under the optimum hydrolysis conditions was 19.78 %, and the reducing capacity of ferrous iron in prepared hydrolysate was 987.13 μmol · L-1. The study also detected the activity of hydrolyzate in terms of inhibiting overoxidation of lipid peroxidation (TBARS), and eliminated the DPPH free radical. The study showed that hydrolysate had a higher antioxidant activity which could inhibit overoxidation of lipid peroxidation and eliminate the DPPH free radical. Although the antioxidant capacity of hydrolysate was lower than that of chemical synthesized antioxidant, apparently higher than that of unhydrolyzed proteins.
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