The use of fatty-acid profiles of the lipids of the rainbow trout (Oncorhynchus mykiss) to differentiate tissue and dietary feed

Fatty acids were determined in several tissues of rainbow trout (Oncorhynchus mykiss), from three fish hatcheries, by gas chromatography of their methyl esters. The qualitative and quantitative changes produced in fatty acid composition in these tissues, over time, related to the diet, were also explored. Through the application of two multivariate statistical methods, factor and cluster analysis, fish and tissues were classified according to the fish hatchery and the tissues categorised in terms of fatty acid composition. Findings indicate that differences in fatty acid composition were related to the fat content of the dietary feed. Three well-differentiated groups of specimens were defined according to the hatchery of origin (diet). Clustering by tissues also gave rise to defined groups.