Impact of Fermentation on the Phytochemical Content and Biological Properties of Moringa oleifera Lam. Shoot Teas

Abstract

This work examined the variation in chemical and biological properties of Moringa oleifera Lam. shoot (MOS) teas prepared under different degrees of fermentation, viz: non-fermented, semi-fermented and fermented. The chemical composition was ascertained via FTIR, GC-MS, total phenolic and total flavonoid content. Also determined were the biological properties, including antioxidant, antimicrobial and alpha-amylase inhibitory activities. The data confirmed that MOS teas were rich in phenolic and flavonoid compounds, with fermented MOS tea displaying the highest phenolic and flavonoid contents. With respect to antioxidant property, all tea extracts exhibited good radical scavenging activities against DPPH⋅, ABTS⋅+ and NO⋅, and the radical scavenging capacity was in the order of non-fermented>semi-fermented>fermented MOS teas. The same trend was also observed for the antimicrobial activities against Staphylococcus aureus and Staphylococcus epidermidis. In contrast, the fermented MOS tea exhibited better α-amylase inhibitory activity compared to the non-fermented and semi-fermented MOS teas.