Reducing SO₂ Doses in Red Wines by Using Grape Stem Extracts as Antioxidants.

Area of Science:

• Enology
• Food Science
• Agricultural Chemistry

Background:

• Sulfur dioxide (SO2) is a crucial wine preservative, but its use presents drawbacks.
• Alternative preservatives are sought to mitigate SO2's negative effects in winemaking.

Purpose of the Study:

• To evaluate the efficacy of Mazuelo grape stem extract and Vinetan® (commercial vine wood extract) as partial substitutes for SO2 in Tempranillo wine.
• To assess the impact of these extracts on wine's chemical composition, antioxidant activity, and sensory properties.

Main Methods:

• Tempranillo wines were treated with grape stem extract or vine wood extract as partial SO2 substitutes.
• A control wine with no extract addition was used for comparison.
• Chemical analysis, antioxidant activity assays, and sensory evaluation were performed after 12 months of bottle storage.

Main Results:

• Total anthocyanin, polyphenol, and flavonoid content were slightly higher in control wines but differences were not significant.
• No significant differences in antioxidant activity were observed among the wines.
• Sensory analysis indicated that wines with partial SO2 substitution exhibited comparable or superior organoleptic properties to the control.

Conclusions:

• Mazuelo grape stem extract and Vinetan® can be effectively used as partial SO2 substitutes in Tempranillo wine.
• These natural extracts maintain wine quality and sensory attributes, presenting a viable alternative to traditional SO2 usage.