Organic plant ingredients in the diet of Rainbow trout (Oncorhynchus mykiss): Impact on fish muscle composition and oxidative stability

Rainbow trout were fed diets containing either fish meal and fish oil (FM‐FO) (control) or diets inwhich 40% of the fishmeal was substituted with a mixture of ingredients grown organically including plant protein concentrate (PP) in combination with either fish oil (FO) as lipid source, or one of the following organic plant oils; rapeseed (RO), linseed/flaxseed (LO), grape seed (GO), or sunflower (SO). The impact of these substitutionswas investigated by measuring fish muscle fatty acid profile as well as oxidative andcolor stability of the fillet during 14 days ice storage. The inclusion of plant protein concentrate did not affect the fatty acid profile significantly but resulted in a slightly improved oxidative stability of the fish fillets as compared to the control diet. The fatty acid profile of the oil used was in general well reflected in the fish muscle fatty acid profile. Fish fed PP‐ROwere themost oxidatively stable during ice storage but the omega‐3 fatty acid content was reduced by 40% compared to fish fed the FM‐FO control diet. Replacing FOby LOwas not suitable as it induced oxidation and the fillet contained 40–50% less of long chain omega‐3 fatty acids