猪血浆蛋白水解物抗氧化作用模式的研究

Study on Antioxidation of Hydrolysates of Porcine Plasma Protein

将猪血浆蛋白(4%浓度,W/W)分别用碱性蛋白酶水解0.5～6h。用pH-Stat方法测定其水解度;同时测定水解物还原能力、金属离子(Cu2+和Fe2+)鳌合能力以及对DPPH自由基清除能力来分析猪血浆蛋白水解物的抗氧化作用模式。结果表明,5h的猪血浆蛋白碱性蛋白酶水解物具有较高的还原能力、合成抗氧化剂所没有的金属鳌合能力以及较强的清除自由基的能力。通过比较不同浓度的水解物抗氧化性实验发现,随着水解物浓度的增高,其抗氧化活性显著增强(p<0.05)。尽管未水解的猪血浆蛋白也有一定的抗氧化活性,但远远低于水解物的抗氧化活性(p<0.05)。由于猪血浆蛋白水解物具有一定的抗氧化活性,所以可以作为金属离子鳌合剂、氢供体和自由基稳定剂用以抑制脂质氧化。

Porcine plasma protein （4%, W/W） was hydrolyzed by alcalase for 0.5 h to 6 h, and the degree of hydrolysis （DH） was determined by pH-Stat method. Meanwhile, reducing power, metal-chelating （Cu^2＋ and Fe^2＋） activity and DPPH radicals scavenging activity of hydrolysates were also determined. The results showed that the products of 5h-hydrolysis have good reducing power, metal ion chelating activity and DPPH radical scavenging activity. Compared among different concentrations of hydrolysates, the antioxidant activity significantly increases （p 〈 0.05） with the increasing of concentration. Although intact porcine plasma protein also displays the antioxidation, it is far less potent than hydrolyzed porcine plasma protein （p 〈 0.05）. In conclusion, enzyme-hydrolyzed porcine plasma protein can act as a metal ion chelator, a hydrogen donor, as well as a radical stabilizer to inhibit lipid oxidation because of its antioxidant activity.