Astaxanthin deposition in fillets of Atlantic salmon Salmo salar L-fed twodietary levels of astaxanthin in combination with three levels of alpha-tocopheryl acetate

The influence of alpha-tocopheryl acetate (alpha-TOAc) on plasma concentrat ion and fillet deposition of dietary astaxanthin was investigated in Atlant ic salmon Salmo salar L. The diets were added 30 or 50 mg kg(-1) astaxanthi n, and 200, 400 or 800mg kg(-1) alpha-TOAc at each astaxanthin level. Impro ved flesh deposition of astaxanthin by 8-14% was achieved for fish fed diet s with 30 and 50 mg kg(-1) astaxanthin, respectively, by the dietary additi on of 800 compared with 200mg kg(-1) alpha-TOAc, These results were support ed by CIE[1976]L*a*b* tristimulus redness measurements (a* value). Plasma a staxanthin concentration mirrored the muscle astaxanthin concentration in t he groups of fsh fed a diet containing 30mg kg(-1) astaxanthin. The salmon fed a high astaxanthin and low alpha-TOAc diet had the highest plasma conce ntration of idoxanthin (P < 0.05). Astaxanthin retention was significantly higher (P<0.001) in salmon fed 30 mg kg(-1) astaxanthin than in those fed 5 0 mg kg(-1) astaxanthin, but was not significantly affected by dietary alph a-TOAc. Liver weight, body weight, specific growth rate, feed/gain ratio an d mortalities were not affected by dietary alpha-TOAc levels, In conclusion , the dietary addition of alpha-TOAc appears to increase astaxanthin fillet deposition in salmonids and may reduce the demand for astaxanthin suppleme ntation. The effect was rather small and requires verification.