Exploring the regulation of metabolic changes mediated by different combined starter cultures on the characteristic flavor compounds and quality of Sichuan-style fermented sausages.

Comprehensive 2D gas chromatography-mass spectrometry (GC × GC-MS) and non-targeted metabolomics were used in this study to systematically investigate the effects of various fermentation agent combinations on the quality characteristics of Sichuan-style fermented sausages. The results indicate that the inoculation of the combined starter culture significantly improves the sensory score and texture characteristics of Sichuan-style sausages, with the overall acceptability score increasing from 77.6 to 79.9-82.9. Furthermore, substantial improvements were observed in key texture parameters, particularly in hardness (increased from 9050.34 g to 10,625.40-16,633.95 g) and chewiness (elevated from 2231.33 g to 2327.23-4505.71 g). Additionally, it reduces both pH values (from 5.86 to 5.83-5.71) and moisture content (from 31.84 % to 31.72-28.99 %). The combined starter culture facilitates the degradation, transformation, and metabolism of proteins and lipids in the sausages, resulting in the production of more metabolites and volatile flavor compounds. In addition, the combined starter culture may promote the release of flavor substances in the sausage spices, thereby enhancing the overall flavor quality. Compared to the control group, the combined starter culture F, comprising Debaryomyces hansenii, Lactobacillus curvatus, Staphylococcus carnosus, and Staphylococcus vitulinus, significantly increased the levels of 60 volatile flavor substances, such as linalool, β-myrcene, and 3-methyl-1-butanol, in the sausages. The combined starter culture F enhanced the levels of 73 secondary metabolites, including beneficial amino acids, organic acids, fatty acids, and others, demonstrating its superior effectiveness in improving the quality characteristics of Sichuan-style fermented sausages.