Profiling of polyphenolics, nutrients and antioxidant potential of germplasm's leaves from seven cultivars of Moringa oleifera Lam.
This work compares the polyphenolics composition, antioxidant activity and contents of selected nutrients in the leaves from seven cultivars of Moringa oleifera ('Tumu', 'Sunyaw', 'Kumasi', 'Techiman', 'China', 'Pakistan Black', and 'Pakistan White') representing the variety in Pakistan. Both the non-enzymatic (DPPH free radical and linoleic acid peroxidation inhibition assays) and enzymatic (superoxide dismutase, peroxidase, and catalase activities) antioxidant capacity was appraised. Regarding the nutritional value, in terms of protein and minerals contents, minor differences were recorded among cultivars. HPLC-PDA-ESI-MSn analysis of the hydro-methanolic extracts of Moringa leaves revealed a wide range of phenolics, highlighting their content in kaempferol derivatives, caffeoylquinic acid, and feruloylquinic acid. The antioxidant capacity of the tested leaves was correlated with the individual phenolics composition in order to identify which compounds were responsible for this beneficial power. The varying (p<0.05) concentration of phenolics together with the antioxidant capacity of the tested leaves established 'Pakistan Black' and 'Techiman' as the most nutritive cultivar among others to be grown in the local area. Moreover, these data support the relevance of genetic variability of Moringa for determining the aptitude as a source of beneficial phenolics and nutrients, allowing to identify the optima cultivars to be grown in southern Asia.