Quality of rainbow trout chilled‐stored after post‐catch holding

Abstract

AbstractThe shelf‐life of headed and gutted rainbow trout (Salmo gairdneri) was evaluated over period of storage at 0°C. There were three groups of samples: (i) fish held at 10°C for 6h and iced, (ii) fish held at 20°C for 6h and iced and (iii) fish held at 30°C for 6h and iced. Quality was assessed over the period of iced storage by measurements of total volatile bases (TVB), hypoxanthine, thiobarbituric acid, pH, water holding capacity (WHC) and tissue compressibility (TC). The results indicated that holding at various time/temperature periods before icing influences quality over the period of iced storage. Deterioration in quality was most pronounced when the fish had been held at high ambient temperatures of 30°C. Hypoxanthine values appeared to give an accurate indication of quality of freshwater fish. There was a linear increase in hypoxanthine values over the period of iced storage for all samples. However, for trout held at 30°C for 6 h before icing the values appeared to be highest. The coefficients of linear regression for fish iced immediately on receipt were lowest per day. It is suggested that hypoxanthine values may be used as chemical indicators of quality of freshwater trout.