Abstract:
Objective of this study was to extract phenolic antioxidants from of 3 fruit residues including Manila cherry (Muntingia calabura L.), Barbados cherry (Malpighia glabra L.) and Indian gooseberry (Phyllanthus emblica L.) by using 2 different solvents, i.e., DI water and ethanol. Phenolic and flavonoid content were investigated by Folin-Ciocalteu and aluminium chloride colorimetric methods, respectively, while antioxidant capacities were estimated by DPPH radical scavenging activity and ferric reducing antioxidant power (FRAP). The result demonstrated that Indian gooseberry extracted with 95% ethanol significantly provided the highest phenolic content of 3,920.3±31.0 mg GAE/g extract (p<0.05), while Barbados cherry and Manila cherry provided phenolic content of 1,397.67±1.53 and 1,005.33±2.52 mg GAE/g extract when extracted with 95% and 50% ethanol respectively. The highest flavonoid content was significantly present in 50% alcoholic Barbados cherry extract (p<0.05). Interestingly, 50% ethanolic Manila cherry extract significantly showed the highest DPPH free radical scavenging activity with IC50 of 1.12±0.01 µg/ml (IC50 of trolox = 1.46±0.02 µg/ml), while Indian gooseberry extracted with 50% ethanol significantly gave the highest FRAP value of 1,639.46±63.07 mg TEAC/g extract (p<0.05) Therefore, the 3 Thai fruit residues have a high potential that could be further utilized for application in cosmetic and other related industries.