Evaluation of effect of different solvent mixtures on the phenolic compound extraction and antioxidant capacity of bitter melon (Momordica charantia)

Abstract

The effect of 13 solvent combinations was evaluated on the determination of total phenolic content and antioxidant capacity of bitter melon (pulp, peel and seeds) using ultrasound. Among all solvents used, the ethanol/water combination (80:20, v/v) showed the best results for extraction process, with higher TPC content for all parts of the studied fruit. The highest antioxidant capacity by DPPH was observed in the extracts with pure acetone for pulp (2.18 ± 0.04 mg ET g−1), and ethanol/water (80:20, v/v) for the peel (7.20 ± 0.09 mg ET g−1) and for seeds (3.01 ± 0.05 mg ET g−1). As for ORAC assay the highest antioxidant capacities were noted in extracts with ethanol/water (80:20, v/v) for all parts of studied fruit. The recovery assays of ethanol/water (80:20, v/v) varied from 81.35 to 108.70% in all parts of fruit. A total of eight phenolic compounds were noted in bitter melon fruit, highlighting the pulp with 477.74 ± 14.49 μg g−1 of 4-hydroxybenzoic acid. Thus, the type of solvent used significantly affected the phenolic compounds extraction and the antioxidant capacity of all parts of bitter melon (pulp, peel and seeds). Bitter melon fruit is a source of antioxidants compounds, mainly the health-benefiting.