Carotenoid pigmentation of salmonid fishes Carotenoid pigmentation of salmonid fishes - recent progress

The purpose of this presentation is to review recent literature on carotenoid pigmentation in salmonid fishes. Consumers have preferences for red-colored products of salmonid fishes, and this is reflected by an increased rate of publications on carotenoids in relation to aspects of quality such as coloration, variation among groups of fish and within fish, and effects of fish production and processing. Recent studies have shown that dietary carotenoid utilization f or muscle pigmentation has a considerable genetic component, enabling selective breeding for color traits. Recently, studies have shown that astaxanthin (3,3´ -dihydroxy-â, â-carotene-4,4´-dione) E/Z isomers accumulate selectively in fish tissues and plasma. All -E-astaxanthin accumulate selectively in muscle and plasma, and 13 Z-astaxanthin in liver of salmonid fishes. The positive effect of lipid content on muscle caroteno id deposition appear to be the only interaction with macronutrients. Also it has been shown that oil composition and a -tocopherol may have slight positive effects on carotenoid utilization. Storage losses of carotenoids may be considerable, and protection from oxygene is of great importance. Carotenoid absorption is slow, and apparently governed by passive diffusion. About 60% of the absorbed carotenoids are metabolized, partly into idoxanthin (3,3´,4´ -trihydroxy- â, â -carotene-4-one) which is rapidly formed from astaxanthin. Carotenoid metabolism and partitioning among body compartments is affected by sex hormones. Positive effects of astaxanthin on on growth and disease resistance may be related to carotenoid antioxidant activity.