Antioxidant Activity of Crude Extract from Raw and Heat-treated Moringa oleifera

Abstract

The aim of this research was to investigate the effect of heat treatment on antioxidant properties of crude extract from Moringa oleifera (peel, pulp, and seed). Total phenolic content and antioxidant properties based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), and metal chelating activity were investigated. Results revealed that crude extract obtained from raw moringa peel showed the highest total phenolic content and DPPH radical scavenging activity (3.65 mg gallic acid eq./g DW and 1.35 mg Trolox eq./g DW), followed by pulp (3.44 mg gallic acid eq./g DW and 1.25 mg Trolox eq./g DW) and seed (2.80 mg gallic acid eq./g DW and 0.91 mg Trolox eq./g DW), respectively. The highest FRAP were obtained from the raw moringa peel extract (3.62 mg ferrous eq./g DW), whereas the highest metal chelating activity was found in raw moringa pulp extract 0.42 mg EDTA eq./g DW). All samples with heat treatment at 100°C for 15 min showed lower total phenolic content and antioxidant properties than crude extract from raw moringa samples (P<0.05).