Wine lees valorization: Pretreatment effect on anthocyanin extraction kinetics from different wine lees.

Abstract

Wine industry generates huge amounts of wastes and by-products, which are sources of high value compounds; including vine prunings, grape stalks, grape pomace and wine lees. For instance, anthocyanin (AC) extraction from grape pomace is a well-known process and several works can be found in literature. Similarly, wine lees (water-waste residues generated during maceration and fermentation steps) have been used to obtain tartaric acid or as a food supplement for animals. Additionally, the recovery of natural colorants (AC) from these waste streams has attracted much attention in the last years due to recent studies showed that the concentration of these colorants are 10 times higher than in grape skins. Thereby, the exploitation of these dregs could constitute to the development of new wine-related products and could also lead to a sustainable growth of the wine industry. As a result, this work is focused on the development of effective green strategies and processes for the selective recovery of bioactive compounds from different wine lees of the first and second fermentation. Microwave (MW), sonication (S) and enzymatic (EM) pre-treatments followed by a solid-liquid extraction have been studied to intensify the extraction of AC in comparison with the conventional extractions