Comparison of nutritional quality, flesh quality, muscle cellularity, and expression of muscle growth-related genes between wild and recirculating aquaculture system (RAS)-farmed black rockfish (Sebastes schlegelii)

摘要

Abstract Black rockfish (Sebastes schlegelii) is a demersal economic species widely distributed in China’s coastal regions. In order to determine the differences between wild (wild group) and recirculating aquaculture system (RAS)-farmed (RAS group) black rockfish, several parameters affecting quality were evaluated, such as proximal, texture, amino acids, fatty acids, muscle cellularity, and the expression of muscle growth-related genes. The results showed that the crude lipid, amino acids, polyunsaturated fatty acids (PUFA), and monosaturated fatty acids (MUFA) contents of RAS group were significantly higher (P < 0.05) than of wild group. Hardness, springiness, chewiness, muscle fiber diameter, cross-sectional area, crude protein, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) contents of wild group were significantly higher than of RAS group (P < 0.05). The muscle fiber density showed a positive and significant correlation with hardness, gumminess, springiness, and chewiness, whereas muscle fiber diameter showed a negative correlation. Expression of muscle growth-related genes including myogenic differentiation antigen (MyoD) and myosin heavy chain (MYH) in wild group was significantly higher than in RAS group. Moreover, MyoD and MYH expression was positively correlated with both muscle fiber density and cross-sectional area, and negatively correlated with fiber diameter, which could be a useful indicator for predicting flesh textural properties. It can be concluded that the exogenous and endogenous factors may determine variations of nutrient composition, flesh quality parameters, and muscle growth patterns of wild and RAS-farmed black rockfish.