Response Surface Methodology Guided Optimization of the Extraction of Natural Phenolics from Mango (Mangifera indica Linn) Leaves

Abstract

Despite the popularity of mango in the Philippines and the reported potential of the leaves of foreign mango cultivars as a source of polyphenolic compounds, no study had been undertaken yet investigating the potentials of the Philippine mango leaves. In this study, the extraction of the polyphenolic compounds from the leaves of the Philippine Carabao mango was optimized using the response surface methodology (RSM). The optimum conditions were also applied on the leaves of the mango cultivars “Pico,” “Apple Mango,” “Sinaging,” and “Sipsipin.” The best phenolic leaf extract was encapsulated using maltodextrin via spray drying and its polyphenolic contents and antioxidant properties were also determined. Results show that acetone and ethanol were better at extracting solvents than methanol and the optimum conditions for extraction were 15% solid loading, 60% solvent concentration, and 0.92 h (acetone) and 1.5 h (ethanol) time. Moreover, the phenolic leaf extract from Carabao contained the highest total phenolic content (TPC) while the extract from Sinaging leaves exerted the greatest free radical scavenging capacity among the different cultivars. Furthermore, the encapsulated polyphenolic leaf extract from Carabao mango contained a significant amount of mangiferin and quercetin-3-β-D-glucopyranoside. Its antioxidant capacity was also better in terms of DPPH (2,2-diphenyl-1-picrylhydrazyl) inhibition and copper reduction compared to ascorbic acid. All the results affirm the great potential of leaves from the local mango cultivars Carabao, Pico, Apple Mango, Sinaging, and Sipsipin as a source of antioxidant phenolic compounds for possible commercial application.