洋葱蛋白及多肽的制备及其体外抗氧化活性评价

对洋葱蛋白、4种不同水解度的粗洋葱多肽、4种分子量范围的纯化多肽组分的水解度、分子量、氨基酸组成、DPPH·清除能力进行了研究。结果表明,洋葱蛋白酶解后分子量大幅降低,必需氨基酸组分和支链氨基酸组分均有所提高,DPPH·清除能力大幅提高,且与水解度成正比;在4种水解度的粗洋葱多肽的纯化组分中,P-III(分子量为1~5kDa)的DPPH·清除能力均为最强,这归功于其合适的分子量分布。该研究为洋葱的高值化利用提供了理论依据。

Preparation of Onion Protein and Peptides and Evaluation of Their Antioxidant Activity in Vitro

The degree of hydrolysis,molecular weight,amino acid composition and DPPH ·scavenging ability of onion protein,4 kinds of crude onion peptides with different degrees of hydrolysis and 4 kinds of purified peptides with different molecular weight ranges are studied.The results show that the molecular weight of onion protein decreases significantly after protease hydrolysis,the essential amino acid components and branched chain amino acid components increase,the DPPH·scavenging ability increases significantly,and is in direct proportion to the degree of hydrolysis,the DPPH·scavenging ability of P-III(molecular weight of 1~5 kDa)is the strongest among the 4 kinds of crude onion peptides with different degrees of hydrolysis,which is attributed to its proper molecular weight distribution.This study has provided a theoretical basis for the high-value utilization of onion.