Dynamics of microbial contamination and hygiene risk points in the production of ready-to-eat Yao meat

Ready-to-eat (RTE) meat products processed under mild or low-temperature conditions are particularly susceptible to microbial contamination. In this study, culture-based methods combined with 16S rRNA gene sequencing were applied to investigate microbial contamination dynamics and identify hygiene risk points throughout the production of Yao meat in a central kitchen in eastern China. The highest microbial loads were observed during the thawing stage, with total viable counts reaching 6.08 ± 0.30 log₁₀ CFU/cm² and coliform counts of 3.35 ± 0.57 log₁₀ CFU/cm². Although cooking significantly reduced microbial levels, a marked increase during the packaging stage indicated post-processing contamination associated with inadequate hygiene control. High relative abundances of potentially spoilage indicator taxa, including Chryseobacterium, Campylobacter, and Pseudomonas, were detected during the kneading stage, suggesting their contribution to downstream contamination. Source tracking analysis revealed that approximately 78.32% of the microbial community in the final product originated from the thawing and kneading stages. In contrast, Bacillus spp. dominated the end product without a clearly identifiable source, indicating the presence of uncharacterized contamination routes. Overall, these results identify critical hygiene risk points during Yao meat production and provide insights into microbial contamination patterns in traditional RTE meat products.