Optimization of ultrasonic-assisted extraction of antioxidants from lemon peel waste using response surface methodology and multi-response desirability function

Abstract

The aim of this study was to model ultrasound-assissted extraction (UAE) of antioxidants from lemon peels using an experimental design coupled with multi-response desirability function. A Box-Behnken Design (BBD) was employed to investigate the effects of sonication time (2, 6, 10 min), ratio of acetone in extraction solvent (0, 50, 100%) and volume of solvent (10, 15, 20 mL) on antioxidant capacity of the peel. 1,1-Diphenyl-2-picryl-hidrazil (DPPH center dot), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(+)), N,N-dimethyl-p-phenylene diamine dihydrocholide (DMPD+) radical scavenging activity, beta-caroten bleaching and reducing power antioxidant assays were responses in the optimization process. It was found that the optimum UAE parameters were extraction time of 6 min, 80% acetone, volume of 12 mL as extraction solvent. Under these optimum UAE conditions, maximum antioxidant capacity of lemon peel was obtained. By this rapid, easy and efficient process, extraction of valuable antioxidants in by-products such as lemon peels can be conducted.