Systematic study on phytochemicals and antioxidant activity of some new and common mulberry cultivars in China

Mulberry is a delicious fruit with high nutritional value. However, there are significant differences in the nutritional values among different mulberry cultivars. Therefore, in this study, the composition of some new and common mulberry cultivars was compared and their potential antioxidant activity evaluated. HPLC and LC-MS analyses revealed that mulberry fruits are rich in polyphenols such as cyanidin-3-O-glucoside (1.25-3.35 g/kg), cyanidin-3-O-rutinoside (0.25-1.50 g/kg), rutin (0.01-0.12 g/kg) and quercetin (0.0068-0.0081 g/kg). Correlation studies explained that the antioxidant activity of mulberry cultivars was closely associated with phenolics, including flavonoids. However, weak correlation was observed between cellular reactive oxygen species (ROS) scavenging ability and bioactive components. Besides, principal component analysis was employed to compare the differences between mulberry cultivars. Concerning high content of nutritional components and antioxidant activity, Hanguo variety was found to be the most beneficial and commercial cultivar among all the tested varieties.