植物乳杆菌B发酵水牛奶产ACE抑制肽的工艺优化及其动态过程分析

Process optimization of ACE inhibitory peptides produced from fermented buffalo milk using Lactobacillus plantarum B and analysis of its dynamic process

采用植物乳杆菌B发酵水牛奶以提高对血管紧张素转化酶(ACE)的抑制活性。以ACE抑制率为指标,在单因素试验的基础上通过响应面法优化发酵工艺,并对发酵过程中产物的动态变化、氨基酸组成和ACE抑制活性进行分析和评价。结果表明:最佳发酵工艺为发酵温度39℃、发酵时间8 h、植物乳杆菌B菌液接种量5%(以发酵水牛奶的体积为基准),在此条件下产物的ACE抑制率为92.42%。在发酵过程中,发酵水牛奶体系中的可溶性蛋白质含量较稳定,保持在2.21~2.37 mg/g。随着发酵时间的延长,发酵水牛奶体系的pH逐渐下降,硬度、稠度、黏附性逐渐升高,发酵6 h后发酵水牛奶体系的持水力上升。氨基酸分析结果表明,水牛奶富含9种必需氨基酸和疏水性氨基酸,且随着发酵时间的延长,游离氨基酸总含量持续下降。

Lactobacllus plantarum B was used to ferment buffalo milk to enhance the inhibitory activity of angiotensin converting enzyme(ACE).Taking ACE inhibition rate as an indicator,the fermentation process was optimized by response surface methodology based on single factor experiments,and the dy-namic changes,amino acid composition,and ACE inhibition activity of the products during fermentation process were analyzed and evaluated.The results showed that the optimal fermentation process was fer-mentation temperature 39 C,fermentation time 8 h,and inoculation of Lactobacillus plantarum B solu-tion 5%(based on the volume of fermented buffalo milk).Under these conditions,the inhibition rate of ACE was 92.42%.During the fermentation process,the soluble protein content in the fermented buffalo milk system was relatively stable,which remained at 2.21 to 2.37 mg/g.With the extension of fermenta-tion time,the pH of the fermented buffalo milk system gradually decreased,and the hardness,consisten-cy,and adhesion gradually increased.The water holding capacity of fermented buffalo milk system in-creased after 6 h of fermentation.The amino acid analysis results showed that buffalo milk was rich in 9 essential amino acids and hydrophobic amino acids,and the total content of free amino acids continued to decrease with the extension of fermentation time.