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Thirty-seven lactic acid bacteria (LAB) strains were isolated from traditional dry sausages collected from Northeast China, including Latilactobacillus sakei (29 strains), Lactiplantibacillus plantarum (4 strains), Latilactobacillus curvatus (2 strains), Weissella hellenica (1 strain), and Lactococcus lactis (1 strain). Some LAB strains had tolerance to high concentrations of sodium chloride (6%), sodium nitrite (150 mg/L NaNO 2), and acid (pH 4.0). They showed good growth and acidification properties and antimicrobial activity. Among them, five LAB strains that exhibited the best technological properties were selected and inoculated in the sausage model to explore their roles in flavor development. The contents of total free amino acids (FAAs) decreased ranging from 109.11 mg/g to 58.06 mg/g. A total of 46 volatile compounds were identified and the contents of volatile compounds increased in the sausage model during fermentation. Partial least squares regression analysis showed that Lb. sakei HRB10, Lb. plantarum MDJ2, W. hellenica HRB6, and Lc. lactis HRB0 promoted the generation of FAAs and volatile compounds in the sausage model. These findings demonstrated that the autochthonous LAB species are promising for the production of sausage with better flavor and fermentation performance. [Display omitted] • Thirty-seven LAB strains were isolated from traditional dry fermented sausages. • The selected strains exhibited high tolerance to salt, sodium nitrite, and acid. • LAB inoculation promoted free amino acid (FAA) and flavor generation. • The FAAs were responsible for the differences in the flavor of sausage models. [ABSTRACT FROM AUTHOR]

The objective of this study was to explore the correlation between bacterial communities and volatile compounds in traditional dry sausages from different regions in Northeast China. The bacterial community structure of dry sausages from five different regions as determined by high-throughput sequencing technology demonstrated that Firmicutes and Proteobacteria were the predominant phyla; Lactobacillus , Staphylococcus , Leuconostoc , Lactococcus and Weissella were the predominant genera; and Staphylococcus xylosus , Lactobacillus sakei , Weissella hellenica , Leuconostoc citreum , Lactococcus raffinolactis and Lactobacillus plantarum were the predominant species. Meanwhile, a total of 120 volatile compounds were detected in sausages from five different regions and mainly included alcohols, acids, aldehydes, ketones, esters and terpenes. Furthermore, the potential correlations between the core bacteria and major volatile compounds (64) were explored based on Spearman's correlation analysis. Positive correlations were found between W. hellenica , Lb. sakei , Lactococcus lactis , Lactobacillus alimentarius , Lb. plantarum and carboxylic acids and alcohols. Lc. lactis , Lb. alimentarius and Lb. plantarum were associated with the production of most esters, aldehydes and ketones. This study provides a deep insight into the relationship between the bacterial community and the volatile flavour profile of dry sausages, which may be helpful for the production of fermented dry sausages. Image 1 • The pdredominant phyla were Firmicutes and Proteobacteria in traditional dry sausage. • A total of 120 volatile compounds were detected in the five traditional sausages. • Five core bacteria improved the formation of volatile compounds in dry sausage. [ABSTRACT FROM AUTHOR]