Microwave hydrodiffusion and gravity as pretreatment for grape dehydration with simultaneous obtaining of high phenolic grape extract

Abstract

The present study aimed to verify the efficiency of microwave hydrodiffusion and gravity (MHG) by partially removing water from grapes while simultaneously obtaining a phenolic-rich extract. In addition, the effect of heating on phenolic compound degradation of pre-dehydrated grapes, the extract, and economic viability to produce both products were evaluated. Thus, a 50% reduction of moisture in the grapes was observed after 10 min while simultaneously obtaining a grape extract. Both products obtained by MHG presented high phenolic compound content and antioxidant capacity. In addition, the use of MHG on an industrial scale was found to be economically viable based on the analysis time, labor cost, and financial return of the products obtained. Thus, the method is efficient, fast, economically viable, and sustainable while simultaneously producing pre-dehydrated grapes and a phenolic-rich extract.

Keywords: Anthocyanins; Antioxidant capacity, economic analysis; Extraction; MHG; Phenolic compounds; Pre-dehydration.