Unraveling the mechanism of "smelling slightly off but tasting delicious" of fermented sour pork via multi-omics analysis: insights from microbial community analysis, flavoromics, untargeted metabolomics and targeted metabolomics.

In this study, the dynamic changes of FSP in different fermentation processes were systematically explored by using multi-omics technology. Esters, alcohols and terpenoids provided fruity, wine-like, and herbal aromas for FSP, which were the main components of pleasant flavors. Fermentation was associated with the deep degradation of proteins, lipids and carbohydrates. With the extension of fermentation time, the enrichment of amino acids, peptides and fatty acid derivatives was the main contributing substance to the "tasting delicious" of FSP, and FAA in 60d FSP increased by 8.82-fold. Notably, the flavor substances of (+/-)-4-Terpineol, Phenylethyl Alcohol, 1-Octen-3-One and 1-Hepten-3-One exhibit concentration-dependent aroma characteristics and may contribute to bad flavor. At the same time, the gradual formation of Butane-1,4-diamine and lipid oxidation products may contribute to the formation of the characteristic volatile "smelling slightly off" flavor of FSP. It provided theoretical basis for the flavor regulation and industrial production of FSP.