Antioxidant Capacity and Phenolic Content of Mimusops elengi Fruit Extract

Abstract

The antioxidant capacities of the phenolic compounds extracted from immature green, mature green and orange ripe fruits of Mimusops elengi were investigated. The compounds were first removed as crude extracts from the fruits using methanol-acetone and then further separated into three different fractions designated as free phenolic acids (F1), soluble phenolic esters (F2) and insoluble phenolic acid esters (F3). The antioxidant capacity of each fraction was determined by radical scavenging (DPPH and ABTS) assays. The antioxidant capacity values of these fractions, expressed as gallic acid equivalents (GAE) by ABTS assay for immature and mature fruits were in the range of 13.5 ± 0.1 - 441.7 ± 4.8 mg/g extract with relative capacities being F2 > F3 > F1. The GAE values for ripe fruits were in the range of 192.3 ± 1.0 – 212.5 ± 4.6 mg/g extract with relative values of F2 ≈ F3 > F1. The antioxidant capacity of the crude extract from immature fruit (GAE = 318.5 ± 12.3 mg/g extract) was higher than that of either the mature (GAE = 234.1 ± 9.2 mg/g extract) or the ripe fruit (GAE = 111.9 ± 4.9 mg/g extract) at p = 0.05. High performance liquid chromatographic analysis confirmed that all phenolic fractions contained gallic acid as a constituent. The total phenolic contents determined by the Folin-Denis assay were consistent with the antioxidant capacity. From the results, Mimusops elengi fruits appeared to be a good source of natural antioxidant.