Use of glutathione in the winemaking of white grape varieties

Abstract

Glutathione is a tripeptide present in grapes, mostly in its reduced form (GSH), which plays a fundamental role in preventing oxidative processes in musts and wines. Its concentration in grapes is influenced by numerous agronomic factors and enological factors. The GSH addition in enological processes is an authorized practice that limits the oxidative reactions, avoiding the deterioration of the wine quality. The use of dry yeast preparations enriched with GSH in its reduced form in white musts at the beginning of the alcoholic fermentation is an interesting alternative to stop oxidations preserving the aroma and sensory quality of wines, especially in varieties with low nitrogen content and that are prone to brown. There are contradictory results regarding the influence of GSH on the organoleptic characterization of wines and so studies of the GSH antioxidant efficiency after the malolactic fermentation and during preservation, aging, or bottling are still necessary.