Effects of combined treatment of electrolysed water and chitosan on the quality attributes and myofibril degradation in farmed obscure puffer fish (Takifugu obscurus) during refrigerated storage

The obscure puffer fish (Takifugu obscurus) is underutilized as a food fish. To improve the quality of puffer fish flesh, the fish samples were preserved after treating them with electrolysed water (EW), a combination of EW and chitosan (EW/chitosan), or a combination of EW and carboxymethyl chitosan (EW/CMC). The effects of these treatments were compared by analysing changes in the total viable count of aerobic bacteria, firmness, total volatile basic nitrogen, trimethylamine, pH, the thiobarbituric acid and sensory attributes of the refrigerated puffer fish. Changes in the myofibril length of puffer fish flesh was also studied, which is related to flesh softening. The findings suggest that during storage, EW/chitosan treatment is more effective than both EW and EW/CMC treatments in inhibiting microbial growth and myofibril degradation, and in maintaining the quality of obscure puffer fish flesh. This could extend the shelf life by 50% of the original shelf-life of about 4 days of the fish samples.