Study On Production Characteristics Of Lactobacillus Helveticus H11 In Milk

Lactobacillus helveticus H11 is a probiotic with independent intellectual property rights in my country isolated from yogurt in Ili Prefecture,Xinjiang.Its fermented milk beverage has high ACE inhibition activity and ACE inhibitory peptides(VPP and IPP).First,L.helveticus H11 was fermented with a single strain,and the viable counts were(2×10~6、5×10~6、1×10~7 CFU/m L),and then 0.003%of the commercial starter Mild1.0,L.helveticus H11 with bacterial counts(2×10~6、5×10~6、1×10~7CFU/m L)were fermented separately.In this study,L.helveticus H11 and commercial starter Mild1.0 strains were fermented in bovine milk in single strain and compound mode.Sexual flavor substances,ACE inhibition rate and content of ACE inhibitory peptides(VPP and IPP)were analyzed to comprehensively evaluate the application potential of L.helveticus H11 in fermented milk.The results showed that:(1)The combination of L.helveticus H11 and commercial starter significantly reduced the fermentation time,among which the fermentation time of M+H11(5×10~6CFU/m L)was the shortest(6.04±0.05h).During storage,L.helveticus H11 compound fermentation had suitable lactic acid degree,fine texture,good viscoelasticity,high sensory score and stable viable count.At the end of storage,the viable count of compound fermented milk L.helveticus H11 was higher than 10~8CFU/m L,which could ensure probiotic activity.(2)During storage,L.helveticus H11-added fermented milk had higher ACE inhibitory activity,among which M+H11(5×10~6CFU/m L)compound fermented milk had the highest ACE inhibition activity(75.08±0.33%)at 14d storage.),while the contents of VPP and IPP were(1.7±0.12μmol/L)and(1.48±0.12μmol/L)respectively.(3)A total of 57 volatile flavor compounds were detected during storage,including 20acid compounds,There are 21 kinds of ketone compounds,9 kinds of ester compounds,4kinds of aldehyde compounds,and 3 kinds of alkane compounds.The fermented milk added with L.helveticus H11 has more kinds of volatile flavor substances,especially when it is stored for 14 days.The most prominent flavor characteristics were consistent with the sensory evaluation results.The research showed that the fermentation characteristics,storage stability,ACE inhibitory activity and sensory quality of fermented milk could be improved by using L.helveticus H11 with 5×10~6 CFU/m L inoculum and commercial starter.This study provides theoretical data support for the industrialization and application of L.helveticus H11,and provides new research ideas for the development of functional dairy products.