Phytochemical and functional characterization of cultivated varieties of Morus alba L. fruits grown in Italy.

Morus alba L. fruits are considered functional foods with an important nutritional value for their high content of polyphenols. Therefore, the type and level of phytochemicals of the soroses from 13 M. alba cultivars grown in Italy were characterized due to the lack of data available about their nutraceutical properties. Mature M. alba fruits exhibited variable polyphenol, flavonoid, anthocyanin, proanthocyanins, and 1-deoxynojirimycin contents which resulted in different antioxidant and α-glucosidase inhibitory activities. Regression models built on UHPLC-HRMS results revealed a strong correlation between the expression of quercetin derivatives, cyanidin 3-O-glucoside, caffeoyl methyl quinates, and 5,5'-dehydrodivanillic acid, and the biological activity of each fruit. On another note, principal component analysis revealed that the quantity of caffeoyl/dicaffeoyl methyl quinate, caffeoylquinic acids, and quercetin derivatives decreased during ripening. The results on the compositional and functional characterization of mature M. alba fruits might improve their consumption and economic value in Italy.