Effects of faba bean water extract and vitamin C/E on muscle texture, nutrition composition and oxidative stress in grass carp (Ctenopharyngodon idella)

Faba bean water extract could improve the muscle textural quality of grass carp (Ctenopharyngodon idella), but would cause oxidative stress, intestinal damage and decrease growth performance. In order to study whether there is a synergistic effect between vitamin C/vitamin E and faba bean water extract to jointly promote the change of C. idella muscle quality, reducing oxidative stress and improving growth performance, this study took ordinary compound feed as a control, 30% of faba bean water extract group, 30% of faba bean water extract + 400 mg/kg of vitamin C+ 200 mg/kg of vitamin E group and faba bean group were the experimental groups, fed (250±20) g C. idella for 120 days. The weight gain rate, condition factor, visceral somatic index, hepatopancreas somatic index, abdominal fat index, feed conversion ratio and survival rate, muscle and intestinal microstructure of C. idella at 120 days were detected. The content of reactive oxygen species (hydrogen peroxide, superoxide anion, hydroxyl radical, oxygen radical, total reactive oxygen species) in the muscles and intestines of C. idella, the activities of enzymes related to the generation and elimination of reactive oxygen species (SOD, CAT, GSH, G6PD, NADPH, COX Ⅰ, COX Ⅲ, COX Ⅳ), the changes of mitochondrial membrane permeability transition pore and the level of mitochondrial membrane potential in muscle cells were detected at 40, 80 and 120 d. The results showed that the growth performance of C. idella in the faba bean water extract group (FBW) and faba bean water extract+V_C/V_E group (FBW+V_C/V_E) was significantly improved compared with the faba bean group, and the muscle texture was significantly improved compared with the control group (P<0.05). The activity of enzymes related to reactive oxygen species (ROS) generation was significantly decreased, and the activities of enzymes related to ROS elimination increased in the faba bean water extract group and the faba bean water extract+V_C/V_E group. In addition, the faba bean water extract+V_C/V_E group showed better antioxidant capacity. Through the observation of microstructure, the muscle fiber density of C. idella in faba bean water extract group and faba bean water extract+V_C/V_E group was significantly increased, the diameter was significantly decreased, and the degree of intestinal injury was significantly lower than that in faba bean group. The present study demonstrated that V_C/V_E play an important role with being added into faba bean water extract in improving texture quality and growth performance of C. idella, and they would have a high potential for quality improving of aquatic products.