Flavor profiling and optimization of large yellow croaker (Larimichthys crocea) in recirculating aquaculture systems: Effects of exercise intensity assessed by advanced analytical techniques

Exercise training is important for improving muscle flavor in RAS-farmed fish, but its effects on the muscle flavor of Larimichthys crocea remain unclear. This study investigated how different swimming intensities (0.4, 0.8, and 1.2 BL/s) modulate muscle flavor using electronic sensory and chromatographic analyses. The moderate-intensity group (0.8 BL/s) showed significantly higher umami and flavor richness than the low and high-intensity groups (P < 0.05). HS-SPME-GC-MS identified 110 differential volatile compounds, with aldehydes as the dominant contributors. Eight key compounds with OAVs ≥1 were detected, including dimethyl trisulfide (highest OAV) and four major aldehydes accounting for 50 % of these compounds. HS-GC-IMS detected 47 volatiles, with 2,3-butanedione as a primary flavor compound. The moderate group showed a more balanced volatile profile, with significantly elevated favorable aldehydes and reduced undesirable compounds (P < 0.05). Overall, moderate swimming intensity improves flavor quality in L. crocea, offering a practical strategy for sustainable aquaculture.