Comparison the quality of rainbow trouts from sport fishing lakes

The quality of rainbow trout from three sport fishing lakes located near Avellino, in the South of Italy, was evaluated and compared with samples of the same fish purchased in market. The trout quality was assessed by microbiological analyses and fatty acids composition. Specific Spoilage Organisms (SSOs) evaluated on skin and gills were higher on of commercial trout, while coliform bacteria belonging to Enterobacteriaceae (EB) appeared at low level in all samples [1]. Fatty acids were characterized by GC/FID [2]. Palmitic acid was the main saturated fatty acid, as already reported. In all samples, the most abundant monounsaturated fatty acids were palmitoleic and oleic acids; and linoleic acid, EPA and DHA within polyunsaturated fatty acids. Linoleic acid presented the highest level in trout from Cesinali lake. EPA and DHA acids were more abundant in commercial farmed fish, likely due to the feeding. In the typical human diet the ratio w3/w6 favors w6 fatty acids (ratio 1.0-16.7); it is beneficial to rebalance this ratio by dietary intake of w3 rich food such as fish. In conclusion, rainbow trout appeared colonized by an autochthonous non-pathogenic microflora. Moreover, trout from sampled sports fishing lakes, fed with food supply free of antibacterial drugs, exhibited good nutritional quality in fatty acids composition.