Dietary lipid and astaxanthin contents affect the pigmentation of Arctic charr (Salvelinus alpinus)

Abstract The most important quality parameter of salmonids is the red color of their skin and muscles. In this contribution, the effects of astaxanthin and dietary lipid content on the pigmentation of Arctic charr (Salvelinus alpinus) were studied. Charrs were fed on diets containing 40, 60, and 80 ppm synthetic astaxanthin together with 10, 18, and 26% dietary lipids for 24 weeks. Results indicated that the astaxanthin concentration in the belly skin and flesh of fish was strongly correlated with both carotenoid and dietary lipid contents, suggesting a significant interaction between diets and the total carotenoid concentration in the belly skin and flesh. The Hunter color L* values of the fillet and the belly skin were inversely related to their carotenoid levels, whereas their a* and b* values were strongly correlated with the total carotenoid concentration. The apparent digestibility coefficient of carotenoids was directly correlated with the level of dietary lipid but inversely correlated with carotenoid contents. A strong correlation between the content of carotenoids retained in the flesh and their digestibility was observed. Thus, the pigmentation of Arctic charr could improve the overall consumer acceptability as well as nutritional and potential market values of Arctic charr. Graphical Abstract