The effects of thermal treatment on the bacterial community and quality characteristics of meatballs during storage

Thermal treatment is a widely applied food processing technology in the meat industry due to its convenience. However, the interpretation of the changes in the bacterial community and quality properties in the thermal processed meat products have not been well established. Therefore, the effects of thermal treatment on the quality characteristics and bacterial communities in meatballs during storage at 4°C were investigated, which will provide a more comprehensive understanding of the influence of thermal treatment on the meat quality. Thermal treatment (121°C, 15 min) decreased the initial total viable bacterial counts by 2.1 log CFU/g and the diversity of the initial bacterial communities in meatballs. Compared with the thermal treatment group, a significantly more rapidly increasing trend of total volatile basic nitrogen and a decreasing trend of pH were observed in the control group. At the end of storage, the bacterial community was dominated by Streptococcus, Acinetobacter and Pseudomonas in the thermal treatment meatballs, whereas Pseudomonas, Pantoea, and Serratia. dominated the bacterial community of the control group. Besides, the predicted metabolic pathways revealed high levels of carbohydrate, amino acid, and lipid metabolism in the control group. This finding could contribute to a deep understanding of the influence of thermal treatment on the meat quality. Moreover, these results could provide a theoretical foundation for the development of alternative and novel nonthermal processing technologies for use in the meat industry.
The findings of this study demonstrated that thermal treatment (121°C, 15 min) could significantly decrease bacterial community diversity and the growth of potential spoilage bacteria in meatballs. In particular, thermal treatment could largely decrease the relative abundance of bacterial metabolic pathways in meatballs, such as carbohydrate, amino acid, and lipid metabolism to maintain the freshness of meatballs during storage.