Optimization of microwave-assisted extraction of proanthocyanidin from eggplant peel by response surface methodology

The microwave-assisted extraction of proanthocyanidin from eggplant peel by response surface methodology was optimized. On the basis of single factor experiment, the Box-Benhnken experimental design with 4 factors and 3 levels was performed with the proanthocyanidin yield as response value. The results showed that the optimal conditions of extraction were follows: solid to solvent ratio 1∶50(g/ml), alcohol volume fraction 70%, microwave power 600 W, and extraction time 89 s. Under the optimized condition, the extraction yield of proanthocyanidin was 3.521%, which was in substantial agreement with the theoretically predicted value.