Abstract
Coffee leaves, which are waste products from coffee pruning, can be used as a source of natural phenolics. This study aims to optimize the extraction process of total phenolic content (TPC) from Arabica coffee leaves using the Microwave-Assisted Extraction (MAE) method, employing the Box–Behnken Design (BBD). Three variables were studied, including ethanol concentration (50%, 73%, 96%), solvent volume (30 mL, 60 mL, 90 mL), and extraction time (3 minutes, 6 minutes, 9 minutes). Total phenolic content was analyzed using the Folin–Ciocalteu method. ANOVA revealed that solvent volume had a significant effect on total phenolic content, whereasethanol concentration and extraction time did not. The optimum conditions, as determined by the Box-Behnken Design (BBD), were obtained at an ethanol concentration of 96%, an ethanol volume of 30 mL, and an extraction time of 6 minutes, with a desirability value of 1 and a TPC of 14.62 mg GAE/g