Optimization of antioxidants and tyrosinase inhibitory activity in mango peels using response surface methodology

The aim of this study is to use a Response Surface Methodology (RSM) to optimize the ethanolic extraction of polyphenol compounds from mango peels. The Nam-Dokmai peel (NDP) showed significantly higher phenolic compounds and tyrosinase inhibitory activity than that of the Tong-Dam peel (TDP) (p < 0.05). A solid-to-liquid ratio of 1:30 was fixed for the RSM. The independent processing variables applied to the RSM were the ethanol concentrations, temperatures, and extraction times. The results show that the second-order polynomial models derived from the responses correlated well with the experimental data (R² > 0.80). The ethanol concentrations and temperature variables significantly affected antioxidant activities (p < 0.05). A low ethanol concentration and a high temperature produced an increased yield while high ethanol concentration and high temperature was the most effective for increasing extractable phenolic content (EPC) and antioxidative activities. Therefore, the optimal conditions that maximized the extraction yields, EPC, and the antioxidant activities for NDP were ethanol proportion of 49%, a temperature of 61 °C, and an extraction time of 221 min.