Ultraviolet radiation application to fish fillet

This study investigated the effects of UV-C irradiation on the microbial load, color, pH, TVB-N content, and textural properties of gilthead seabream (Sparus aurata) fillets. Microbiological analyses revealed that UV-C treatment significantly reduced aerobic colony counts and slowed microbial growth during storage. The initial natural loads of coliforms, Enterobacteriaceae, Escherichia coli, and Vibrio cholerae were low (<10 CFU/g), and none were detected throughout storage in either the control or UV-C-treated groups. Aerobic colony counts increased from 5.20×10³ to 1.20×10⁷ CFU/g in control samples, whereas UV-C-treated fillets exhibited a less pronounced increase (from 1.30×10⁴ to 1.10×10⁶ CFU/g). Color analyses showed that UV-C did not affect the L*, a*, and b* values initially (P < 0.05), but helped maintain color stability over storage. No significant differences were observed in pH values between groups. TVB-N values in the control group reached 30.17 mg/100 g by day 9, while UV-C-treated fillets measured 17.61 mg/100 g, indicating that UV-C irradiation significantly inhibited the formation of nitrogenous compounds associated with spoilage (P < 0.05). Textural analysis demonstrated that UV-C treatment enhanced fillet elasticity (increasing from 7.36 mm to 9.73 mm), suggesting improved freshness and quality. The maintenance of hardness (13.59 N to 15.69 N) indicated preserved structural integrity and texture. No significant changes were observed in other textural parameters. Overall, UV-C irradiation proved to be an effective method for extending the shelf life of fish fillets by enhancing microbial safety and quality attributes.