Extração de compostos fenólicos de bagaços de uvas Vitis vinifera e potencialidade de ação fungicida sobre fungos fitopatogênios

Abstract

After vinification, a process related to the transformation of grapes into wine, grape pomace constitutes one of the main residues. Studies have been carried out to identify their chemical composition in order to total or partial reuse and subsequent transformation into new products, which would result in adding value to these by products, thus minimizing disposal. In order to attend the demand for innovative products and new applications for this residue, in the present work the conditions for phenolic compounds extraction from grape pomace of Vitis vinifera varieties - Riesling, Pinot Noir and Gewurztraminer - and the potential of theses extracts as a fungicidal agent were evaluated. The pomace was collected from wineries in the northeast region of RS during the 2024 grape harvest. The extracts were obtained by solid/liquid extraction, in a 20:80 ratio of raw or freeze-dried grape pomace/70% ethanol, at 50ºC, 350 rpm for 120 minutes. The antimicrobial evaluation tests were performed using Botrytis cinerea fungus in cultures in solid and liquid media. In cultivation on solid media, a higher percentage of fungal inhibition (85.5%) was identified with the use of freeze-dried pomace extract from the Riesling grape. For liquid cultures, with the use of extracts from freeze-dried pomace from Riesling grapes and raw pomace from Pinot Noir, an average of 85% inhibition was achieved. In this sense, despite being preliminary, the results obtained so far are important, showing perspectives for additional studies aiming to the reuse and also to adding value to winemaking residue. [resumo fornecido pelo autor]