益生菌发酵藜麦制备ACE抑制肽

Study on the preparation of ACE inhibitory peptides by probiotic fermentation of quinoa

目的:探究利用益生菌发酵藜麦制备血管紧张素转换酶(ACE)抑制发酵液潜在的能力及发酵工艺对其的影响。方法:以藜麦为原料,ACE抑制率为指标,对18株乳酸菌和12株酵母制备具有ACE抑制能力的发酵液进行了筛选,并对接种量、发酵温度、发酵时间进行了正交优化;对发酵液中的肽进行液质鉴定,并对筛选出的肽进行体内试验评价降压效果。结果:30株菌中Lactobacillus paracasei L2(副干酪乳杆菌)作用效果最好,发酵藜麦制备的发酵液ACE抑制率高达(86.50±0.25)%;Lactobacillus paracasei L2菌株发酵藜麦制备具有ACE抑制活性的发酵液最佳发酵条件为接种量5%,发酵时间48 h,发酵温度34℃,该条件下ACE抑制率最高,为(90.41±0.16)%;通过对液质鉴定结果比对数据库得到两条ACE抑制效果较好的两条肽NIFRPFAPEL和AALEAPRILNL,它们均能够在自发性高血压大鼠(SHR)体内显现出显著的降血压作用,均在灌胃4 h时达到最佳降压效果。收缩压(SBP)分别降低(2.67±0.21),(3.46±0.01)kPa,舒张压(DBP)分别下降(29.36±0.54),(22.33±0.77)kPa。且NIFRPFAPEL和AALEAPRI-LNL均对Wistar-Kyoto大鼠(WKY)的血压不产生影响。结论:藜麦是制备具有ACE抑制活性发酵液的优质谷物原料,且从发酵液中分离制备的NIFRPFAPEL和AALEAPRILNL ACE抑制肽可用于降血压功能食品或者药品的开发。

Objective:The potential ability of probiotics to prepare angiotensin-converting enzyme(ACE)inhibitory fermentation broth from quinoa and the effects of fermentation process on it were investigated.Methods:In this study,18 strains of lactic acid bacteria and 12 strains of yeast were screened for their ability to prepare ACE inhibitory fermentation broth using quinoa as the raw material and the ACE inhibition rate as an indicator.The inoculum amount,fermentation temperature and fermentation time were optimized by orthogonal tests.Finally,the peptides in the fermentation broth were identified,and the selected peptides were tested in vivo to evaluate the antihypertensive effect.Results:Lactobacillus paracasei L2 had the best effect among the 30 strains,and the ACE inhibition rate of the fermentation broth prepared by fermenting quinoa was as high as(86.50±0.25)%;The optimal fermentation conditions for the preparation of ACE inhibitory fermentation broth by fermenting quinoa with Lactobacillus paracasei L2 strain were 5%inoculum,48 h fermentation time,and 34℃fermentation temperature.Under these conditions,the ACE inhibition rate was the highest,which was(90.41±0.16)%;By comparing the results of liquid quality identification with the database,two peptides NIFRPFAPEL and AALEAPRILNL with better ACE inhibition effect were obtained.Both NIFRPFAPEL and AALEAPRILNL could significantly lower blood pressure in spontaneously hypertensive rats(SHR),and both achieved the best blood pressure lowering effect at 6 h after gavage.Systolic blood pressure(SBP)decreased by(2.67±0.21)and(3.46±0.01)kPa,and diastolic blood pressure(DBP)decreased by(29.36±0.54)and(22.33±0.77)kPa,respectively.And NIFRPFAPEL and AALEAPRI-LNL had no effect on blood pressure in Wistar-Kyoto rats(WKY).Conclusion:Therefore,quinoa is a high-quality grain raw material for preparing ACE inhibitory fermentation broth,and NIFRPFAPEL and AALEAPRILNL can be used for the development of blood pressure-lowering functional foods or medicines.