Relationship between Microbial Community Structure and Quality of Suanyu Products

To understand the effects of microbial communities on product quality of different Suanyu products,pH,lactic acid,free amino acids,biogenic amines in different Suanyu products and microbial diversity information were analyzed by 16S rDNA genes sequencing,and volatile flavors were analyzed by solid phase microextraction and GC-MS. The correlation between microbial diversity and various indicators of different Suanyu products was examined. The results showed that the eight commercially available Suanyu products had lower levels of biogenic amines. There were six essential amino acids in Suanyu products,and the sample 2 had the most amino acid species contributing to the taste. The umami amino acids were detected in all seven kinds of Suanyu products,and the umami amino acids in samples 4 and 6 contributed a lot to the taste. GC-MS analysis showed that alcohols,aldehydes and hydrocarbons were the main flavor contributors in Suanyu products,and 3-methyl-1-butanol,heptanal and γ-terpinene were the key flavors substance in Suanyu products. The dominant bacteria door in Suanyu products was the Firmicutes,and the dominant genus was Lactobacillus and Streptococcus. RDA showed that increasing Lactobacillus in the Suanyu products contributed to the release of glutamic acid and aspartate. Staphylococcus and Weissella were beneficial to promote the release of aldehydes from Suanyu products,and the sweetness of heptanal. The increase in the abundance of Tetragenococcus in Suanyu products was beneficial to the release of key flavor substances of 3-methyl-1-butanol and γ-terpinene,giving a unique aromatic odor and pine oil aroma.