Optimization of Microwave-Assisted Extraction Parameters to Enhance Phenolic and Antioxidant Recovery from

Kokang leaves (Lepisanthes amoena), a plant native to Kalimantan, have long been utilized by local communities for treating wounds and maintaining skin health. This species holds promising potential as a natural source of bioactive compounds, particularly due to its antimicrobial and antioxidant constituents that are valuable in both health and food applications. Phenolics and flavonoids are naturally occurring compounds frequently found in plant-derived materials. This study aimed to determine the levels of phenolics, flavonoids, and antioxidant activity in kokang leaf powder extracted using Microwave-Assisted Extraction (MAE). The experimental design incorporated variations in solvent ratios (1:10, 1:15, and 1:20) and extraction durations (2, 3, and 4 minutes). Data were processed using two-way ANOVA at a 95% confidence level. The findings indicated that the interaction between solvent ratio and extraction time significantly influenced the total phenolic content, total flavonoid content, and antioxidant activity of the kokang leaf extract powder. The treatment with a 1:10 solvent ratio and 2-minute extraction time yielded the highest values, including total phenolics (258.6 mg GAE/g), total flavonoids (74.8 mg QE/g), and antioxidant activity (IC50) of 29.4 μg/mL.