Influence of dietary linseed and sunflower oil on sensory characteristics of rainbow trout (Oncorhynchus mykiss)

This study describes the effects of dietary linseed and sunflower oil on the sensory characteristics of rainbow trout (Oncorhynchus mykiss) fillets. Rainbow trout were fed a diet containing either 2.5% or 5% of linseed or sunflower oil or 5% mixture of both oils (2.5% of each). Control group received a commercial feed mixture. A selected and trained panel carried out descriptive sensory tests on fish fillet cross-sections. The addition of vegetable oil into fish feed did not affect firmness, juiciness or intensity of total taste but had a significant impact on colour, intensity of odour and fish oily taste. A higher content of n-3 polyunsaturated fatty acids (PUFA) in linseed oil, in comparison with sunflower oil, is often responsible for the development of an off-flavour. No trout fillet was rejected owing to the off-flavour presence. Both concentrations of linseed oil decreased the intensity of fish oily taste. Therefore, for the partial replacement of fish oil in rainbow trout feed it is recommended the use linseed oil, which is a good source of n-3 PUFA. Author's Abstract.