Microbial safety and chemical characteristics of sausage coated by chitosan and postbiotics obtained from Lactobacillus bulgaricus during cold storage.

This study investigated the antioxidant and antimicrobial properties, as well as the volatile compounds, of Lactobacillus bulgaricus (L. bulgaricus) postbiotics (at concentration of 150 and 300 mg/L) and their combination with chitosan coatings (0.5% and 1%) on sausage quality (with 100 ppm nitrite) during 40 days of cold storage. The results were compared to a control group, as well as to sausages containing commercial formulation (120 ppm) and reduced (100 ppm) levels of nitrite. To further assess the antimicrobial effects, it also inoculated E. coli and Staphylococcus aureus into the sausages in order to examine how the postbiotics and chitosan coatings impacted the growth of these foodborne pathogens during the 40-day cold storage period. The reults indicated that those containing 300 mg/L postbiotic and 1% chitosan generally met the desired condition for pH, moisture, fat, and total volatile base-nitrogen. These samples also showed the strongest inhibition of mesophilic and psychrophilic bacteria, mold and yeast. Notably, no E. coli or S. aureus were detected in any of the samples, indicating that the postbiotic and chitosan combination effectively inhibited the growth of these pathogens in sausages. The findings suggest that using chitosan coatings and L. bulgaricus postbiotic can enhance the quality of sausages, ultimately lowering the risk of contamination by harmful bacteria and improving overall food safety.