Comparison of proximate and fatty acid compositions of wild brown trout and farmed rainbow trout

Abstract

The purpose of this study was to compare the fatty acid and proximate composition of two commercially exploited trout species (wild brown trout (WBT) and farmed rainbow trout (FRT)). The mean crude lipid content in FRT (4.3%) was significantly higher than that in WBT (2.7%). Total saturated fatty acid concentration (27.7%) in WBT was significantly higher than that in FRT (21.4%). However, monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) concentrations in FRT were significantly greater than those of WBT. While the omega-6 PUFA concentration of WBT was fairly low, total omega-3 PUFA concentration was significantly higher compared with omega-6 PUFA. In contrast to WBT, the FRT contained high omega-6 and low omega-3 PUFA concentrations. Linolenic, docosahexaenoic (DHA), eicosapentaenoic (EPA) acids and C20:3n-3 components of omega-3 PUFAs were higher and significantly different between the two species. The ratio of omega-3 to omega-6 fatty acids in WBT was significantly higher compared to FRT. The results indicated that muscle lipids of both species are rich in EPA + DHA, thus beneficial in human nutrition.

Keywords: SFA, MUFA, PUFA, Salmo trutta macrostigma, Oncorhynchus mykiss, EPA, DHA