Comparative Analysis of Nutritional Quality, Flavor-Active Amino Acids, and Chromatic Characteristics of Wild and Farmed Red Sea Bream (Pagrus major) Across Growth Stages

To address the quality divergence between wild and cage-farmed red sea bream (Pagrus major), we conducted a comparative analysis of their proximate composition, fatty acid and amino acid profiles, and chromatic characteristics across varying size and growth stages. Farmed fish exhibited substantial lipid deposition (peaking at 4.77% in F4), yielding a high relative percentage of n-3 long-chain polyunsaturated fatty acids. In contrast, wild fish maintained a leaner muscle profile (<2.43% lipid) and were uniquely characterized by an elevated abundance of C22:1n-9 (up to 11.52%), distinguishing them from farmed cohorts. Regarding sensory quality, large-sized wild specimens contained significantly higher concentrations of delicious amino acids (DAA, up to 8.83 g/100 g), particularly glycine and alanine, indicating a superior flavor profile. Colorimetric analysis demonstrated that wild fish maintained vivid reddish pigmentation in the caudal fin (a* = 8.73), whereas farmed fish exhibited marked skin darkening. These findings elucidate a distinct phenotypic and nutritional divergence: intensive farming enhances overall somatic lipid retention, while natural marine environments optimize flavor-active amino acid accumulation and visual appeal, providing critical baseline markers to guide precision aquaculture.