Pigmentation and Composition of Flesh of Atlantic Salmon Fed Diets Supplemented with the YeastPhaffia rhodozyma

Abstract

Abstract In a pigmentation trial, Atlantic salmon Salmo salar in ocean pens were fed diets supplemented with the red yeast Phaffia rhodozyma, a control diet supplemented with synthetic astaxanthin, and a nonpigmented control diet. Yeast diets contained spray-dried untreated P. rhodozyma, heat-treated and spray-dried P. rhodozyma, and heat-treated and chemically treated spray-dried P. rhodozyma. Growth, weight, and fork length of all fish increased linearly with feeding and were not significantly different at the end of the study. Astaxanthin concentration in all pigmented fish increased linearly and ranged from 3.26 to 3.78 mg/kg after 150 d of feeding. Apart from the nonpigmented diet, astaxanthin concentration was not significantly different between fish fed the untreated or treated red yeast and those fed the synthetic astaxanthin diet (control). Assessment of astaxanthin isomers corroborated the assimilation of the (3R,3′R) isomer from all P. rhodozyma diets. Moisture, ash, and protein in all fish dec...