Characteristics of microbial community in Linyi fermented pork sausage and their correlation with quality: effects of the single Lactobacillus starter

This study aimed to assess the effect of five Lactobacillus starters adding on the quality and bacterial diversity of Linyi fermented sausage (LFS). The relationships between the differentially abundant microorganisms and product quality were explored. The Lactobacillus bulgaricus (B), Lactobacillus casei (C), Lactobacillus reuteri (RE) and Lactobacillus rhamnosus (RH) were inoculated into the meat batter with single strains, and the commercial starter Lactiplantibacillus plantarum (P) was used as the control group. The results demonstrated that the B and C samples presented better fermentation characteristics (lower pH and aw), the most content of free amino acids, and significantly improved sausage sensory and texture properties. As for the volatile profile identified by headspace gas chromatography-ion mobility spectrometry, aldehydes were enriched in the B sample, which imparted a stronger fat, floral, honey-like fragrance. High-throughput sequencing showed that 11 bacteria genera were identified as differentially abundant. Spearman correlation revealed that excessive Klebsiella, Serratia and Hafnia-Obesumbacterium might not contribute to improving the quality of LFSs. Collectively, these findings are providing the theoretical guidance for the screening of functional starters.