Comparative profiling of secondary metabolites and antioxidant properties of twelve Morus varieties: Insights into the diversity of M. alba and M. nigra grown in Sicily

This work analyzed potential phytochemical differences in bioactive compounds, antioxidant activity and metabolic profiles of 12 different varieties of Morus alba and Morus nigra fruits grown in Sicily by Liquid chromatography coupled to High Resolution Mass Spectrometry. Through UV/Vis assays, variations in in bioactive compounds were observed, recording higher contents of polyphenols and anthocyanins in M. nigra species. Spectrophotometric assays also revealed the absence of ellagitannins and proanthocyanidins in the same samples, while the amount of anthocyanins varied not only among species but also among cultivars. From a functional point of view, both scavenging and radical-reducing abilities were evaluated by biochemical assays, while Cellular Antioxidant assay was used to monitor antioxidant properties on a human cell-based biological system. These assays confirmed that M. nigra varieties possessed higher antioxidant activity in terms of radical scavenging and reducing antioxidant power. On the other hand, the cellular model system provided insights into the potential health implications of Morus spp. with values comparable to other common berries. Finally, metabolomic analysis illuminated the chemical diversity within Morus spp. by highlighting distinct metabolic fingerprints and allowing discrimination between species and varieties. Anthocyanins emerged as key metabolites for this discrimination, with additional compounds contributing to genotype-specific profiles. Overall, these results underscore the importance of genetic diversity in assessing the health properties of Morus spp. with implications for improving their nutritional and medicinal value in Mediterranean areas, particularly Sicily.