Agiorgitiko grape pomace as a sustainable source of bioactive compounds

Abstract

Worldwide Greece is famous for the cultivation of vines and the production of their obtained products such as wine, grape juice and raisins. This constitutes an economically factor important for further growth and development. However, Grape pomace is considered the main waste in the wine industry and it consists of skin residues, broken cells with pulp remains, stalks, and seeds. More specifically Grape pomace (GPs) is defined by high contents of phenolics due to an incomplete extraction during the winemaking process. These phenolics are secondary plant metabolites with the ability to have a beneficial impact on human health because of their antioxidant activity and antimicrobial, antiviral, and anti-inflammatory properties. Therefore, grape pomace establishes an inexpensive source of phytochemicals that can be used by food industries. Subsequently, rework of grape pomace has drawn the attention to sustainability of food processing practices. Proper and efficient extraction methods are necessary in order to achieve an adequate recovery of the winemaking wastes. This review summarizes the extraction of Polyphenols from grapes skin of the “Agiorgitiko” variety. In this respect, ultrasound application has been selected as an extraction method and the effect of three different extraction solvents water, ethanol and water/ethanol (1:1) are analyzed. Furthermore, the techniques used for extract characterization are analyzed, with attention on sample preparation, separation, and analysis of total phenolics content and % antioxidant activity.