蛋白酶种类及水解时间对猪血浆蛋白水解物抗氧化性和乳化性的影响

Antioxidant Activity and Emulsifying Properties of Porcine Plasma Protein Hydrolysates as Influenced by Different Hydrolysis Times and Proteases

主要探讨蛋白酶种类及水解时间对猪血浆蛋白水解物抗氧化活性以及乳化能力的影响。采用3种蛋白酶(碱性蛋白酶、木瓜蛋白酶和中性蛋白酶)对猪血浆蛋白分别水解20、40、60、80、120 min。测定猪血浆蛋白水解物的抗氧化活性、乳化活力、乳化稳定性以及分子质量的变化趋势。结果表明:相对于木瓜蛋白酶和中性蛋白酶来说,碱性蛋白酶能够显著提高猪血浆蛋白水解物的还原能力、ABTS^+·和1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除能力(P<0.05),而且碱性蛋白酶水解60 min时所获得的猪血浆蛋白水解物具有最高的乳化活力和乳化稳定性(P<0.05)。另外,随着水解时间的延长,猪血浆蛋白水解物中小于5 k D的成分显著增加(P<0.05),且碱性蛋白酶对猪血浆蛋白的酶解效果最佳(P<0.05)。上述结果表明,碱性蛋白酶适度水解猪血浆蛋白以后获得的水解物同时具有良好的抗氧化活性和乳化能力。

The effect of different hydrolysis times and type of protease on the antioxidant activity and emulsifying activity of porcine plasma protein hydrolysates（PPPH） was investigated. Porcine plasma protein was hydrolyzed with three different commercial proteases（alcalase, neutral protease and papain） for 0 to 120 min. The antioxidant activity, emulsifying activity index（EAI）, emulsion stability index（ESI） and molecular weight distribution of the hydrolysates were evaluated. The results showed that compared with neutral protease and papain, the PPPH prepared with alcalase rendered the highest antioxidant activity（reducing power, ABTS＋· radical-scavenging activity and DPPH radical-scavenging activity）（P〈 0.05）. Moreover, the hydrolysate prepared by alcalase hydrolysis for 60 min showed the highest EAI and ESI（P〈 0.05）. The proportion of less than 5 k D was significantly increased with increasing hydrolysis time（P〈 0.05）, and the alcalase provided the best hydrolysis efficiency（P 〈0.05）. Therefore, these results demonstrated that modest hydrolysis by alcalase could yield PPPH with higher antioxidant capacity and emulsifying properties, which can be used as a potential additive in the food industry.