Optimization of ultrasound-assisted antioxidant compounds extraction from germinated chickpea using response surface methodology

•Ultrasound has effect on yield of antioxidant extraction from chickpea.•Effectiveness of ultrasound is better than solvent extraction technic.•Antioxidant properties of germinated chickpea is better than ungerminated chickpea.•Maximum extraction yield should be provided at optimum extraction conditions.

The optimum ultrasound assisted extraction (UAE) parameters (power, time and solid/liquid ratio) for the extraction of antioxidant compounds from germinated chickpea were determined by response surface methodology (RSM). Box-Behnken design (BBD) was employed to investigate the effects of three independent variables, total phenolic content (TPC), DPPH radical scavenging activity and trolox equivalent antioxidant capacity (TEAC). The prediction of the response was carried out by a second-order polynomial model and regression analysis revealed that more than 88% of the variation can be explained by the models. The optimum conditions for UAE of germinated chickpea samples were; %40 solid/liquid ratio, 36.16% amplitude power and 20.17 min and the experimental values of TPC, DPPH radical scavenging activity and TEAC were, 14.77 mg GAE/mL extract, 43.31% and 73.59%, respectively. Results confirmed that germination results in higher antioxidant values and RSM optimization of UAE is more efficient than conventional extraction.