Abstract:A new antibacterial solution, UVC-GA was prepared by exposing gallic acid (GA) to UV-C for 12 h. Tilapia skins were treated with UVC-GA, GA, or deionized water (DI), and then stored at 0 ℃. Results showed that the sensory shelf-lives of the skin samples treated with DI, GA, and UVC-GA were five, seven, and eight days, respectively. The dominant bacterial genera in the DI-treated skins on day five (DI5) were Pseudoalteromonas (31.31%), Candidatus-Bacilloplama (21.5%), and Litorimicrobium (17.11%). The dominant genera in the GA-treated skins on day seven (GA7) were Aliivibrio (42.4%), Pseudoalteromonas (20.51%), and Psychrobacter (10.32%). The dominant bacterial genera in the UVC-GA-treated skins on day eight (UVC-GA8) were Aliivibrio (29.81%), Candidatus-Bacilloplama (20.9%) and Moritella (11.11%). The relative abundance of Aliivibrio and Pseudoalteromonas in UVC-GA8 was lower than that in DI5 and GA7. In addition, the amounts of quality-related chemical indicators, including TVB-N, TVC, putrescine, cadaverine, inosine, and hypoxanthine were lower in the UVC-GA-treated samples than those in the DI- and GA-treated samples; whereas inosine-5′-monophosphate content was higher in the UVC-GA-treated skins. The K value of UVC-GA8 was significantly lower than that of DI5 and GA7. V-shaped pH-time curves were obtained for both the DI and GA groups, whereas the pH decreased with time in the UVC-GA group. These results suggested that UVC-GA inhibited the deterioration of tilapia skin quality. The prolongation of the shelf life of tilapia skins might be attributed to UVC-GA-induced alterations in the microflora, changes in the contents of TVB-N, TVC, biogenic amines, and ATP complexes, and decrease in the K value of the skins stored at 0 ℃.
