Effects of UVC light-emitting diodes on microbial safety and quality attributes of raw tuna fillets

Ultraviolet light-emitting diodes (UV-LEDs) have become widespread for decontaminating the surfaces of food products and their packaging as a safer alternative to traditional mercury-vapor based UV lamps. This study aimed to investigate the effect of UVC- LEDs (275 nm) on the inactivation of foodborne pathogens and quality attributes of raw tuna fillets. Raw tuna fillets inoculated with cocktails of Salmonella Typhimurium, Listeria monocytogenes , and Escherichia coli O157:H7 were exposed to UVC-LEDs at 500-4000 mJ/cm 2 . UVC-LED treatments of single-layer tuna fillets at a dose of 4000 mJ/cm 2 resulted in 1.31-, 1.86-, and 1.77- log reduction of S . Typhimurium, L . monocytogenes , and E . coli O157:H7, respectively. The pH value, water-holding capacity, metmyoglobin, texture, and color characteristics of tuna fillets were not significantly ( p  > 0.05) changed following the UVC-LED treatment at radiation doses up to 4000 mJ/cm 2 . Nonetheless, the UVC-LED irradiation led to increased levels of lipid oxidation in tuna fillets. Overall, the present study demonstrates that UVC-LEDs are a promising technology to reduce microbial flora and maintain the physicochemical properties of fish products.