CAROTENOIDS DETERMINATION IN THE GONADS OF ATLANTIC BLUEFIN TUNA (Thunnus thynnus L.)

This paper presents the first investigation on the carotenoids composition in the gonads of wild Atlantic bluefin tuna (ABT) Thunnus thynnus. The objective of this study was to investigate the carotenoids composition of the gonads, at pre-spawning stage, of Atlantic bluefin tuna (ABT) Thunnus thynnus, with the aim to obtain a greater knowledge of the bluefin reproductive cycle at a specific tissue molecular composition level, and to provide new data for the possible formulation of specific broodstock diets for the aquaculture of this endangered species. Moreover since tuna eggs are also widely consumed raw, the knowledge on their carotenoids composition is important considering the positive effects of these micronutrients in our diet and of a precise knowledge of the food composition and quality. Astaxanthin was the main carotenoid detected in the samples investigated with an average content of 7.4 μg/g, w/w; β-cryptoxanthin and β-carotene were also detected in small amounts. Astaxanthin chiral isomers were also directly separated on a chiral column and a distribution of respectively (3S,3’S) 13.1%, (3R,3’S) 47.8%, (3R,3’R) 8.4% astaxanthin isomers in the gonads of wild tuna samples was determined for the first time.