Abstract: In order to improve the quality and flavor of fermented sausages, the effects of mixtures of Saccharomyces cerevisiae Y-8 and Lactiplantibacillus plantarum Z43 in different proportions on the physical and chemical properties, volatile flavor compounds and fatty acids of fermented sausages were explored. The volatile flavor compounds and fatty acids were determined by gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS), respectively. The results showed that the addition of S. cerevisiae Y-8 promoted the production of esters and alcohols, reduced the acetic acid content, increased the final pH and the relative content of oleic acid, and rapidly reduced the number of enterobacteria in fermented sausages. Based on variable importance in the projection (VIP > 1) values obtained from the model established using orthogonal partial least squares discriminant analysis (OPLS-DA), 17 differential volatile flavor compounds were identified, which could effectively distinguish among all fermented sausage samples. Fermented sausage inoculated with L. plantarum Z43 and S. cerevisiae Y-8 in a ratio of 20:1 (the inoculum amount of L. plantarum Z43 was 107 CFU/g) had the highest overall sensory evaluation score and chrominance value, and its hardness was significantly higher than that of the other groups (P < 0.05). In addition, its content of 3-hydroxy-2-butanone was apparently higher than those of the other three groups. Inoculation with S. cerevisiae Y-8 could impart fermented sausages with high alcoholic and estery aromas, effectively eliminate the sour taste, and improve the quality and safety of fermented sausages. This finding can provide a reference for the application of S. cerevisiae in fermented meat products.

Key words: Saccharomyces cerevisiae; fermented sausage; volatile flavor substance; fatty acid