Evaluation and optimization of microwave-assisted extraction of bioactive compounds from eggplant peel by-product

摘要

A three-level five-factor central composite design was used for microwave-assistedextraction of bioactive compounds from eggplant peel. The extraction yields, totalphenolic content (TPC), total flavonoid content (TFC), total anthocyanin content(TAC), and DPPH radical scavenging activity, reported as IC_(50), were optimized bychanging the microwave power, extraction time, liquid–solid ratio, ethanol concentration,and pH of solvent. The extraction yield, TAC, TPC, and TFC significantly increased(p < .01) parallel to the increase in microwave power and the use of lowerethanol concentrations and lower liquid–solid ratios. The maximum predicted extractionyield (3.27%), TPC (1,049.84 μg GAE/ml), TFC (130.40 μg QE/ml), and TAC(6.99 mg/L) and the minimum predicted IC_(50) (0.52 ml/mg) were simultaneously obtainedwhen power, extraction time, liquid–solid ratio, ethanol concentration, andpH of solvent were 269.82 W, 7.98 min, 5.01 ml/g, 73.49%, and 3.06%, respectively.Overall, bioactive compounds could be effectively extracted from eggplant peels viaoptimized microwave conditions.