Ultraviolet (UV-C) radiation: An innovative non-thermal technology for quality enhancement and shelf life extension of reef cod (Epinephelus diacanthus) fillets during chilled storage

Abstract

Recently, advanced processing techniques have gained attention for mitigating spoilage in fish and fishery products. Fresh seafood quality deteriorates at various stages, including cultivation, processing, harvesting, transportation, and post-purchase storage, primarily due to microbial contamination, poor handling, inadequate packaging, suboptimal storage practices, limited on-farm facilities and adverse weather conditions. UV-C radiation has emerged as a promising method for reducing spoilage by inactivating pathogenic and spoilage microorganisms through DNA lesions and disruption of cellular enzyme activity and membrane integrity. This study evaluated the impact of UV-C radiation on the quality and shelf life of reef cod (Epinephelus diacanthus) fillets during chilled storage (4±1°C). Fillets were exposed to UV-C for 20s, 40s, and 60s and stored for 15 days. Fillets treated with UV-C for 20s exhibited superior overall performance across various quality parameters. Chemical spoilage indicators such as trimethylamine nitrogen (TMA-N) and total volatile basic nitrogen (TVB-N) increased over time, with the 20s treatment group recording the lowest TVB-N value (20.3 mg/100g) on Day 10. Rancidity markers, including peroxide value (PV) and thiobarbituric acid (TBA) value, were minimized in the 20s group, with PV and TBA values of 2.5 meq O2/kg and 0.98 mg MDA/kg, respectively, on Day 10. Microbial analysis revealed significantly lower total plate counts (TPC) in UV-C-treated samples, with the 20s treatment maintaining TPC of 5.2 log CFU/g compared to 6.5 log CFU/g in the control. Sensory and textural evaluations highlighted better acceptability and structural integrity in the 20s-treated fillets for up to 10 days. These findings demonstrate that UV-C treatment, particularly at 20s, effectively preserves seafood quality during chilled storage and holds potential for wider application in the seafood industry.