Addition of glutathione-rich inactivated yeasts to white musts: effects on wine composition and sensory quality
Glutathione plays a key role in preventing some oxidative processes during winemaking. This molecule limits the must enzymatic oxidation, reacts with caffeic acid and generates a colourless compound that prevents subsequent browning. It also has a protective effect on wine aroma, preventing the oxidation of the volatile compounds with a high sensory impact.
In this work, the effects of the addition of a commercial preparation derived from inactivated yeasts (IDY) on the chemical composition and sensory profile of white wines made from three varieties (Tempranillo Blanco, Garnacha Blanca and Viura) from the D.O.Ca. La Rioja (Spain) were evaluated. The IDY preparation containing glutathione (Glutastar, Lallemand, S.L.) was added at a dose of 30 g/Hl to the racked musts.
The obtained results showed differences depending on the grape variety. In Tempranillo Blanco and Viura, the addition of IDY increased the concentration of glutathione and decreased the concentration of catechins and hydroxycinnamic acids. In Viura, some aromatic compounds (amyl alcohols, isoamyl acetate, hexyl acetate and octanoic acid) increased.Overall, the IDY treatment did not influence the organoleptic characteristics of the wines, with slight variety-related modifications in the aromatic profile.
The addition of IDY could be an interesting alternative to slow down oxidation and preserve the aroma of white wines, but its effects have a variety dependence. In this study, the highest antioxidant efficacy was obtained in the Viura variety.
Issue: ICGWS 2023
1Instituto de Ciencias de la Vid y del Vino (Gobierno de La Rioja, CSIC, Universidad de La Rioja). Finca La Grajera, Carretera de Burgos, km 6, 26071 Logroño, La Rioja, España)
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glutathione, specific inactivating yeasts, white wines, oxidation, aroma