Impact of ultrasonication on the metabolite profile, nutritional quality, and antioxidant properties of Moringa oleifera Lam. leaf powder

This work investigated the impact of ultrasonication on the metabolite profile, nutritional quality, and antioxidant properties of Moringa oleifera Lam. leaf powder (MOLP). Subsequent to ultrasonication, gas chromatography mass spectrometry (GC-MS) was adopted to profile the samples, with 35 metabolites observed in raw and processed MOLP and categorised into seven metabolite classes: acids, alcohols, fatty acids, esters, glycosides, sugars and their derivatives, as well as amino acids and their derivatives. Ultrasonication facilitated the release of crude protein, fat, and fibre of MOLP. It also significantly enhanced the extraction of total phenolic content (16.61–18.30 mg GAE/g), total flavonoid content (27.12–35.87 mg QE/g), ferric reducing antioxidant power (FRAP) (130.86–152.01 mM TE/g), and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) %inhibition (7.47–83.22%) of MOLP. Structural analyses (FTIR and SEM) revealed modifications in the functional groups, the morphology of the protein body, and other components in MOLP. Overall, these findings suggest that ultrasonication enhanced the availability of health-promoting metabolites of MOLP, making it suitable for various applications in food products.