Optimization Of Lactiplantibacillus Plantarum P-8 Fermented Soy Milk Formulation Based On Dynamic In Vitro Bionic Digestion System

Fermented soymilk is an extremely important part of soymilk products.It has received extensive attention from the market due to its rich nutritional value and probiotic properties.Therefore,it is of great significance to research and develop fermented soymilk products.In this study,Streptococcus salivarius subsp.thermophilus S10(S.salivarius subsp.thermophilus S10)and Lactiplantibacillus plantarum P-8(L.plantarum P-8)were used as control strains and experimental strains,respectively.Based on different raw material ratios(2.3%or 3%of protein),fermentation temperature(37℃or42℃and inoculation amount(5.0×10~6CFU/m L or 2.0×10~7CFU/m L)for soymilk fermentation,a group of fermented soymilk products with good fermentation characteristics and storage stability,and can significantly alleviate the soybean odor were selected to provide data support for commercial applications.The results are as follows:(1)At the end of fermentation(p H 4.60±0.02),the number of viable bacteria in each group was higher than 1.0×10~8CFU/m L;the results of dynamic in vitro biomimetic digestion experiments showed that under the comprehensive conditions of 2.3%protein content,42℃fermentation and 5.0×10~6CFU/m L inoculation amount,the components of fermented soy milk can affect L.Plantarum P-8 provides optimal protection,and the survival rate was as high as 26.52%when it was kept in the stomach for 100 min.In addition,the sensory evaluation score under this condition was the highest,the tissue state was delicate,the taste was refreshing and the flavor was soft.(2)The monitoring results of S10 group and P-8 group for 28 days showed that both fermented soymilks had great storage stability.Compared with the S10 group,the viable count,acidity,viscosity and water holding capacity of the P-8 group showed a more stable trend.(3)Fermentation is the main reason for the difference in the metabolic profile of volatile flavor substances,and fermentation strains can cause further differences.The total amount of soybean odor substances in the fermented soymilk of the two groups was significantly reduced,and the P-8 group decreased more significantly.Hexanal,benzaldehyde and(E,E)-2,4-decadienal decreased significantly in both fermented soymilk(P<0.01),and(E)-2-hexenal decreased significantly in P-8 group(P<0.001).At the same time,P-8 group enriched more flavor-friendly volatile metabolites such as ethanol,acetic acid,butyl acetate and ethyl acetate.