Comparative quality loss in wild and cultured rainbow trout (Oncorhynchus mykiss) during chilling storage

Abstract

The aim of this study was to determine and compare differences in sensory, chemical and microbiological post-mortem changes between wild and farmed rainbow trout (Oncorhynchus mykiss). Lipid content was higher (5.77%) in wild fish than cultured fish (3.02%). Wild fish were very rich in n-3 fatty acids. Although wild fish were preferred to cultured fish due to the taste and flavour, shelf life of both wild and cultured rainbow trout was 14 days with demerit scores of 16 and 14, respectively. Chemical analyses showed that lipid oxidation and hydrolysis developed at a higher rate in wild rainbow trout. Histamine was not detected in any samples throughout the storage period apart from wild rainbow trout at 7 days of storage. Initial total viable counts (TVC) of fish was 3.59 log CFU/g for cultured rainbow trout and 3.36 log CFU/g for wild rainbow trout, which showed high quality of fish. Coliform and E. coli were not detected for both groups. When fish were unacceptable at the days of 14, TVC content was 6.16 log CFU/g for wild rainbow trout and 6.35 log CFU/g for cultured rainbow trout.