不同蛋白酶水解高温花生粕和低温花生粕及其水解产物抗氧化活性的对比研究

Comparison of Hydrolyses of Heat-and Cold-pressed Peanut Meals by Different Proteases and Antioxidant Activities of Their Hydrolysates

由于高温花生粕中的花生蛋白在高温压榨过程中高度变性,因此在食品工业中蛋白利用率较低。本研究通过对比高温花生粕和低温花生粕经过不同商业蛋白酶（Alcalase 2.4 L,Neutrase,Papain,Protamex及Flavorzyme 500 MG）水解后水解产物特性的蛋白回收率、水解度、分子量分布及抗氧化活性,确定高温花生粕是否适合采用生物酶解的方式利用其中的蛋白质并筛选合适的蛋白酶。结果表明,高温花生粕经不同蛋白酶水解后,其蛋白质利用率均在60.61~67.86%,与低温花生粕相当;水解度及分子量分布方面,高温花生粕Flavorzyme水解产物的DH最高,高达44.92%,且含有较多的〈3 ku小分子肽及游离氨基酸;此外,高温花生粕不同酶水解产物的DPPH自由基清除活性均高于低温花生粕,这可能是由于高温花生粕水解产物中含有较多具有供电子的小分子肽、游离氨基酸以及高温压榨过程中生成的美拉德反应产物。

Given the high degree of protein denaturation during the high-temperature pressing process,heat-pressed peanut meals have a low protein utilization rate in the food industry.In this study,heat-and cold-pressed peanut meals were hydrolyzed using different commercial proteases（e.g.,alcalase 2.4 L,neutrase,papain,protamex,and flavorzyme 500 mg）.The protein recovery,degree of hydrolysis（DH）,molecular weight（MW） distribution,and antioxidant activities of their hydrolysates were compared to verify whether enzymatic hydrolysis was suitable to utilize these proteins in heat-pressed peanut meals and to select the appropriate protease.The results showed that the protein recoveries of heat-pressed peanut meals after hydrolysis by different proteases were 60.61~67.86%,which were comparable to the values of cold-pressed peanut meals.The highest DH（44.92%） was observed in the heat-pressed peanut meal hydrolysate prepared by flavorzyme hydrolysis,and there were numerous small peptides with a MW of 〈3 ku and free amino acids.In addition,the 1,1-diphenyl-2-picryl-hydrazyl radical-scavenging activities of different heat-pressed peanut meal hydrolysates were higher than those in cold-pressed peanut meal hydrolysates.This may be because heat-pressed peanut meal hydrolysates contain a larger number of small peptides and free amino acids with electron-donating ability as well as Maillard reaction products generated during the heat-pressing process.