Multi-Omics Analysis of the Effect of Litsea cubeba Essential Oil on the Flavor of Fermented Sausages

Traditional fermented sausages are widely consumed in China but often face quality and safety risks due to contamination by spoilage and pathogenic microorganisms during natural fermentation. This study investigated the effect of Litsea cubeba essential oil (LCEO) on the microbial community structure and volatile flavor compounds (VFCs) of fermented sausages using multi-omics approaches, including 16S/ITS amplicon sequencing and HS-SPME-GC-MS. The results showed that LCEO significantly altered the microbial community, increasing the relative abundance of Lactobacillus from 4.65% to 76.22% and Debaryomyces from 11.95% to 22.35%, while reducing Staphylococcus and Aspergillus by 47.01% to 4.55% and 37.28% to 17.09%, respectively. A total of 695 VFCs were identified, with terpenoids and hydrocarbons being the most abundant. A differential analysis revealed that LCEO enhanced the relative content of key aroma-active compounds, including ethyl esters and aldehydes, with odor activity values exceeding 1 for fruity-related compounds such as decanoic acid, ethyl ester and nonanoic acid, methyl ester. Strikingly, the elevated levels of these fruity esters translated into significantly higher sensory scores for odor (p < 0.05) in LCEO-treated sausages, as panelists consistently perceived a pronounced fruity and fresh aroma profile, ultimately leading to a superior overall acceptability compared to the control. A correlation analysis indicated strong positive associations between Lactobacillus, Debaryomyces, and major flavor-contributing esters. In conclusion, LCEO potentially reduces the microbial risks and improves the flavor profile of fermented sausages, making it a promising natural additive for meat fermentation.