Abstract:

In this study, the optimum microwave assisted extraction (MAE) parameters (solid/liquid ratio, time and power) determined by Box-Behnken Design (BBD) of Response Surface Methodology (RSM) for the extraction of antioxidant compounds from grapevine leaves. The BBD was used to define the effects of independent variables on Total Phenolic Content (TPC), DPPH radical scavenging activity and Trolox Equivalent Antioxidant Capacity (TEAC). Second-order polynomial model and regression analysis were used for prediction optimum point. The optimum conditions for MAE of grapevine leaves were determined as solid/liquid ratio of 30%, power of 300 W and time of 300 sec. All of the models was found valid and significant independent variables (R2) were found as 0.9282, 0.9340 and 0.9380 and the predicted experimental value of design 58.204 mg GAE/ mL extract, 95.905% and 65.123% for TPC, DPPH scavenging activity and TEAC, respectively. The results of the present showed that MAE of grapevine leaves produce the extracts with a higher antioxidant values in a shorter time when compared with solvent extraction.

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