Effects of different raw materials on bacterial community and flavor compounds in fermented red sour soup

Red Sour Soup (RSS), a traditional Miao delicacy from Guizhou, China, is primarily fermented using tomatoes, red peppers, white wine, glutinous rice flour, and salt. To elucidate the mechanisms underlying flavor formation of RSS, this study examined four fundamental components of RSS. Findings revealed that ethanol plays a role in inhibiting the proliferation of harmful microorganisms. A total of 42 volatile flavor compounds were identified, including ethyl acetate and phenylethanol. Notably, 3-hexenol emerged as the principal aromatic compound from tomato fermentation, while heptanol was the key compound derived from pepper fermentation. Lactobacillus became the predominant microbial community. Lactobacillus, Leuconostoc , and Micrococcus influenced flavor compound production through various metabolic pathways, with Lactobacillus enhancing the formation of ethyl hexanoate and ethyl octanoate, whereas Kocuria appeared to suppress the production of several volatile flavor compounds. This study offers a theoretical framework to advance the production and research of RSS.