Biochemical changes in freshwater rainbow trout (Oncorhynchus mykiss) during chilled storage

The sensory characteristics and biochemical freshness-indicator contents of rainbow trout (Oncorhynchus mykiss) stored for up to 12 days (a) in ice without previous gutting (group A), Cb) in ice after gutting (group B) and (c) under refrigeration (4-5 degrees C) after gutting and vacuum-packing (group C) were compared. Acceptable freshness was maintained for five days in groups A and C, and for six days in group B. The results indicate that the hypoxanthine ratio ie hypoxanthine content: (inosine monophosphate + inosine + hypoxanthine content) and K-1 ie (inosine + hypoxanthine content): (inosine monophosphate + inosine + hypoxanthine content) are both useful indicators of the freshness of trout stored in ice, regardless of whether or not they have been gutted beforehand. (C) 1999 Society of Chemical Industry.