Lutein does not influence flesh astaxanthin pigmentation in the Atlantic salmon (Salmo salar L.)

The goal of the present study was to evaluate the absorption efficiency, deposition, retention and possible interaction of two xanthophylls given in diets to the Atlantic salmon. Triplicate groups of the Atlantic salmon were fed diets containing 55 mg/kg astaxanthin, and 0, 11 or 23 mg/kg lutein from around 300 g to an average end weight of 1200 g.No dietary inclusion affected the growth or feed conversion. Furthermore, the flesh content of astaxanthin was similar in all groups, as were the blood levels of astaxanthin after a meal. This indicates that there was no or very little interaction between these pigments for absorption. A weak but non-significant tendency of lower flesh astaxanthin content, at a feed dose of 23 mg/kg lutein, warrants further studies. The absorption of lutein appeared to be very low compared to astaxanthin, as the ratios astaxanthin:lutein in the muscle and plasma were increased from 2.5 in the diet, to almost 25. This may indicate the existence of a selective absorption mechanism for astaxanthin or alternatively, clear discrimination against the absorption of lutein.