Impact of electron-beam dose on microbial diversity and succession dynamics of refrigerated poultry meat during extended storage.

Electron-beam (E-beam) irradiation is used as a post-harvest intervention to reduce microbial contamination in poultry products, yet less is known about how irradiation doses influence microbial succession during extended refrigerated storage. This study evaluated the effects of E-beam dose on the bacterial community structure of tray-packed chicken tenderloins stored under refrigeration for 27 days. Chicken tenderloins were treated with 0, 1.0, 1.5, 2.5, or 3.5 kGy and sampled on Days 3, 7, 24, and 27. Bacterial communities were characterized using 16S rRNA amplicon sequencing, and alpha diversity, beta diversity, and differential abundance analyses were used to assess dose-response and storage-associated changes. E-beam treatment and storage time interacted to significantly influence microbial community composition, as measured by Weighted UniFrac and Bray-Curtis distances (P = 0.038 and P = 0.05, respectively). Storage time was a major driver of succession, with significant differences in Shannon entropy (P = 0.03) and Faith's phylogenetic diversity (P = 0.0001), along with changes in abundance-based community structure by Bray-Curtis dissimilarity (Q = 0.002). Weighted UniFrac analysis further showed significant differences across storage days, including Day 3 compared with Days 7, 24, and 27 (Q < 0.0061) and Day 7 compared with Days 24 and 27 (Q < 0.05). Taxonomic analysis displayed Pseudomonas increased throughout storage and approached approximately 80% relative abundance by the final sampling day (ANCOM, P < 0.05). Sequential ANCOM-BC comparisons further exhibited the enrichment of Pseudomonas from Day 3 to Day 7 (LFC = +3.52) and from Day 7 to Day 24 (LFC = +2.71). In contrast, several early-storage or competing taxa, including Bacillus, Fabibacter, Yersinia, Carnobacterium, Aeromonas, declined across later comparisons. E-beam dose also influenced community structure, with the highest dose (3.5 kGy) producing the most pronounced early shifts in microbial community composition. Overall, these findings suggest that E-beam irradiation shapes the initial poultry meat microbiome, while refrigerated storage remains a dominant factor influencing late-stage convergence toward a lower-diversity, Pseudomonas-dominated community.