Effects of Short-Term Depuration on Muscle Nutritional Quality and Flavor Composition in Carassius auratus gibelio

This study evaluated the effects of short-term depuration under different salinity levels on the muscle nutritional composition and quality of Carassius auratus gibelio, aiming to provide guidance for enhancing the value of farmed crucian carp. A total of 240 fish (450 ± 50 g) were reared in recirculating aquaculture systems at salinities of 0‰ (S0), 3‰ (S3), 6‰ (S6), and 9‰ (S9) for 0 (D0), 5 (D5), and 10 days (D10). Dorsal muscle samples were analyzed for proximate composition, amino acids, fatty acids, flavor-related nucleotides, geosmin, and volatile compounds. Short-term depuration significantly improved muscle protein content, total amino acids, and umami amino acids. Culturing at 6‰ salinity for 10 days enhanced crude protein, total amino acids, umami amino acids, and lipid indices associated with cardiovascular benefits, while 9‰ salinity for 5 days increased crude lipid, total umami amino acids content, and the essential amino acid index (EAAI). Geosmin content decreased under moderate salinity but tended to accumulate at higher salinities. Amino acid scoring identified lysine, methionine, and cysteine as limiting under certain conditions, indicating a need for supplementation. Overall, short-term salinity depuration effectively improves muscle nutritional composition, fatty acid profiles, and flavor attributes, offering a practical approach to producing higher-value C. auratus gibelio with enhanced health benefits and consumer appeal.