Abstract: To investigate the effects of 60Co-γ irradiation on lemon-flavored boneless chicken feet, this study analyzed the quality and microbiological characteristics of samples subjected to different irradiation doses (0, 2.6, 5.7, 9.1, and 11.3 kGy) by using an electronic tongue, an electronic nose, texture profile analysis, and scanning electron microscopy as well as examining volatile basic nitrogen content, malondialdehyde (MDA) content, collagen properties, microbial counts, and bacterial community structure. The results indicated that irradiation effectively reduced microbial counts. The aerobic plate count in samples irradiated at 9.1 kGy and above fell below the detection limit (< 10 CFU/g), while the number of molds and yeasts was below the detection limit (< 10 CFU/g) in samples irradiated at 2.6 kGy and above. In terms of taste, samples irradiated at 9.1 kGy and above showed differences primarily in umami, richness, bitterness, and sourness compared to non-irradiated samples. Regarding odor, samples treated with 11.3 kGy irradiation differed mainly in the contents of hydrides, inorganic sulfides, nitrogen oxides, alcohols and some aroma compounds, aromatic compounds and organic sulfides, alkanes, and hydrocarbons compared to non-irradiated samples. Compared to unirradiated samples, the soluble collagen content and collagen solubility of samples irradiated with 9.1 kGy increased by 173% and 167%, respectively (P < 0.05); the insoluble collagen content and total collagen content of samples irradiated with 11.3 kGy decreased by 32% and 30%, respectively (P < 0.05). The volatile basic nitrogen and MDA contents significantly decreased in samples treated with 5.7 kGy irradiation (P < 0.05), indicating inhibition of protein and lipid oxidation. Bacterial diversity analysis revealed that bacterial richness decreased with increasing irradiation dose, and medium- and high-dose treatments impacted bacterial community composition. The absolute dominant bacterial phylum was Proteobacteria, and the absolute dominant genus was Psychrobacter, with no significant difference in the dominant genera before and after irradiation. However, the characteristic bacterial communities varied with irradiation dose. Notably, the genus Streptococcus, whose relative abundance increased under high-dose (11.3 kGy) irradiation, showed a significant positive correlation with lipid oxidation and collagen dissolution. In conclusion, 6 kGy is recommended as the optimal irradiation dose for lemon-flavored boneless chicken feet. This study provides a theoretical basis for the precise optimization of irradiation processes based on multi-omics correlation analysis.

Key words: lemon-flavored boneless chicken feet; 60Co-γ irradiation; quality; collagen; bacterial community structure