具有抗氧化活性乳清发酵物的组分分析

利用乳酸菌对乳清蛋白进行发酵,检测发酵物的抗氧化能力。以DPPH自由基清除率为指标,测得其对DPPH自由基清除率为66.95%,经5kDa超滤后,分级产物对DPPH自由基的清除率提高至79%。经Tricine-SDS-PAGE电泳分析可知,具有抗氧化活性的乳清肽相对分子量小于2kDa。对发酵产物的氨基酸分析发现,与抗氧化活性关系密切的疏水性氨基酸、芳香族氨基酸的含量占总含量的70.17%,表现出显著的抗氧化活性。同时,其营养成分丰富,富含人体所需的必需氨基酸,适宜作为功能性食品开发。

Composition analysis of the whey fermentation product with the antioxidant activity

Using Lactobacillus to ferment whey protein,the antioxidant capacity of the fermentation product were analyzed.For the fermentation products,the DPPH radical scavenging rate adopted as the evaluation standard of the antioxidant capacity was 66.95%.The DPPH radical scavenging rate of graded product increased to 79% after 5kDa ultrafiltration.Tricine-SDS-PAGE electrophoresis analysis showed that,the molecular weight of the whey peptides which had antioxidant activity clearly was concentrated in less than 2kDa.Amino acid analysis of fermentation products demonstrated that,the content of the hydrophobic amino acids and aromatic amino acid closely related to the antioxidant activity were more than 70.17%.At the same time,these fermented products were full of the essential amino acids,and were suitable to develop new functional food.