Thyme essential oil and sausage diameter effects on biogenic amine formation and microbiological load in smoked horse meat sausage

Thyme essential oil (TEO) and sausage diameter effects on biogenic amines (BA) formation and microbial communities in traditional Xinjiang smoked horse meat sausage were studied. Evaluation of the pH, moisture content, and microorganisms population of smoked horsemeat sausage was done. Significant differences due to sausage size were found for BA and microbial populations. Smaller diameter sausages showed decreased (P < 0.05) BA compared to the larger diameter sausages. The use of TEO greatly reduced BA (tyramine, putrescine, cadaverine, and histamine). In addition, TEO decreased the total bacterial count and more specifically the Gram-negative Enterobacteriaceae family (P < 0.05). High throughput sequencing showed that essential oil (EO) treatment and the difference in sausage diameter did not change the predominant microbiota in sausages during fermentation. However, the relative abundance of the microbiota can be changed. The correlation heat map showed relationships between the microbial community and BA production. Staphylococcus, Leuconostoc, and Lactobacillus showed a strong positive relationship with BA formation.