DietaryAdonis. aestivalisextract improved the flesh pigmentation, antioxidative status and shelf-life of rainbow trout (Oncorhynchus mykiss)

This study investigated the effects ofAdonis aestivalisextract rich in astaxanthin on the pigmentation and antioxidative status of rainbow trout. Five diets were designed as the control diet, the synthetic astaxanthin diet with astaxanthin inclusion of 100 mg/kg, andA. aestivalisextract-supplemented diets with 1.7, 3.4 and 6.8 g/kg extract addition containing 50, 100 and 200 mg/kg astaxanthin, respectively. Then, the five diets were fed to rainbow trout with an initial body weight of 6.27 +/- 0.04g for 6 weeks. Compared to the control group, the supplementation ofA. aestivalisextracts significantly increased the redness(a*) and yellowness(b*), and decreased the flesh drip loss and thawing loss (p < .05). T-SOD and MDA in flesh and serum were significantly decreased, and the inhibition ability of -OH was increased in all the astaxanthin-supplemented groups (p < .05). The redness(a*), astaxanthin content and antioxidant indexes of 3.4 g/kg extract group showed the similar levels to the synthetic astaxanthin group (p > .05). In conclusion, dietaryA. aestivalisextract improved the flesh colour and the antioxidative status of rainbow trout, and the supplemental level was suggested to be 3.4 g/kg with astaxanthin inclusion of 100 mg/kg diet.