Deparment of Biochemistry, Microbiology and Physics, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria (Manuscript received 17 November 2016; accepted for publication 13 February 2017)
Abstract. In this study the rate of accumulation of both main pigments in Salmonidae – astaxanthin (AX) and canthaxanthin (CX) in different muscle tissues of Rainbowtrout(OncorhynchusmykissW.)andtheirdistributioninfleshandheartwasresearched. Experimentalfishwerereared100daysintwotanksastwo parallel experimental groups and fed with market feed, containing 40 mg.kg-1 AX and 25 mg.kg-1 CX. The diet was according to the manufacturer’s recommendations, which are consistent with fish size and water temperature. The accumulated pigment quantities in the muscle tissues, were measured everytwentydaysbyhighperformanceliquidchromatographywithphotodiodearraydetectionafterselectivexanthophyllextraction. ThehighestratesofAX and CX deposition were recorded on the 60th and 80th day. The average contents of AX and CX were at the end of the trial 1.943 ± 0.167 mg.kg-1 and 0.807 ± 0.021 mg.kg-1 in skeletal muscle and 0.683 ±0.055 mg.kg-1 and 0.280 ±0.017 mg.kg-1 in cardio muscle, respectively.