Optimization of Extraction of Bioactive Compounds from Different Types of Grape Pomace Produced at Wineries and Distilleries

Natural extracts obtained from grape pomace are particularly interesting, due to the substantial variety of valuable compounds present with health benefits, specifically phenolic compounds such as anthocyanins, trans‐resveratrol, quercetin, and proanthocyanidins. The production of such extracts has been recognized as a profitable way to valorize grape byproducts, which are low‐value and most abundant. First, the effect of the solvent on the extraction of bioactive compounds from grape pomace is studied. The selected solvents are water and ethanol, biocompatible and available in wineries and distilleries. Then, different types of grape pomace obtained along the various stages of current industrial winemaking and distillation processes are analyzed. As a result, the best stage of the winemaking and distillation processes for pomace valorization is identified, corresponding to the grape byproduct with the highest potential as source of bioactive compounds. These studies were performed with Vitis vinifera variety of Tempranillo grapes (same year, same vineyard).