Pigmentation of salmonid - a comparison of astaxanthin and cantaxanthin as pigment sources for rainbow trout

Abstract

Rainbow trout were fed a diet supplemented with astaxanthin and cantaxanthin. The ratios of astaxanthin to cantaxanthin were determined in plasma, faeces and flesh. During 65 days of feeding the flesh reached a level of 4.5 mg carotenoids/kg. A linear relationship between growth and carotenoid level was found for growths below 150g/65 days. Astaxanthin seemed to be absorbed more readily from the diet and also deposited at a higher ratio than cantaxanthin in the flesh. Pylorus seems to be the site for absorption of astaxanthin.