Unlocking the Nutritional Potential of Endemic Salmonid Species (Black Sea Salmon, Salmo labrax): Carotenoids and Their Impact on Fillet Characteristics

This study evaluated the fillet quality of Black Sea salmon following diets supplemented with carotenoids such as astaxanthin, canthaxanthin, and lycopene. Carotenoid supplementation improved crude protein, essential amino acids, and unsaturated fatty acids. Astaxanthin and canthaxanthin increased crude fat and texture, while lycopene reduced these values. Lycopene-fed fish exhibited the highest polyunsaturated/saturated fatty acid ratio and improved health indices, including fish lipid quality (FLQ) and health-promoting index (HPI). The highest PUFA/SFA ratios were observed at 200-300 ppm lycopene. Amino acid scores also improved, with canthaxanthin elevating the digestible indispensable amino acid score (DIAAS) of young children, categorizing fillets as excellent protein sources. In older age groups, lycopene at 100 ppm yielded the highest DIAAS scores. Notably, carotenoidsupplemented fillets contained higher levels of glycine, alanine, and omega-3 fatty acids (EPA, DHA), supporting muscle structure and cardiovascular health. Lycopene emerged as a potent antioxidant, demonstrating untapped potential for aquaculture applications. These findings underline the multifaceted benefits of carotenoids in enhancing meat and lipid quality, emphasizing the need for future research on optimized supplementation strategies to maximize both health benefits and aquaculture performance.