Physicochemical changes of tuna fish (Euthynnus affinis) throughout refrigerated storage condition. A preliminary study

Deterioration of fresh fish is indicated by its physical and chemical changes. The gills colour changes and level of total volatile base nitrogen (TVBN) and trimethylamine (TMA) formed in fresh tuna fish (Euthynnus affinis) stored in refrigerated condition were investigated as indices of spoilage. Food Drug Administration (FDA) recommended to store fishes up to two days under refrigerated (4 °C) temperature. However, there is an issue in hypermarket where the storage length could exceed for several days and possibly for the spoilage fish to mix with the fresh fish. Gills colour examination using colour meter (physical test) and determination of TVBN and TMA using kjedahl steam distillation (chemical test) were conducted throughout seven days of storage. The a* value decreased significantly with storage time from 18.34 to 10.40 (p