Grape and Apple Pomaces from Southern Brazil: Valorization of By-Products through Investigation of Their Antioxidant Potential

The extraction process of bioactive compounds from grape and apple pomaces was optimized using a response surface methodology to evaluate the effect of ethanol concentration, time and temperature on the extraction of total phenolic content, antioxidant activity by radical scavenging 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) method and individual phenolics by high performance liquid chromatography (HPLC). Optimizing suggests that the best condition for total phenolic and gallic acid extraction from grape pomace was obtained in intermediate level (60% ethanol, 60 °C, 30 min) while 80% ethano...