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Effect of processing on phenolics of wines
V Z Blanco1, J M Auw, C A Sims
1Food Science and Human Nutrition Department, University of Florida, Gainesville 32611-0370, USA.
Advances in Experimental Medicine and Biology
|May 23, 1998
Summary
Grape processing significantly impacts phenolic compounds, influencing wine quality. Different grape varieties respond uniquely to treatments like skin contact, affecting taste and bitterness.
Area of Science:
- Enology
- Viticulture
- Food Chemistry
Background:
- Grape phenolics are crucial for wine's sensory attributes and chemical stability.
- Processing methods like crushing, pressing, and skin contact can alter phenolic profiles.
Purpose of the Study:
- To investigate the impact of distinct processing techniques on the phenolic composition of three diverse grape varieties.
- To correlate phenolic profiles with sensory attributes such as bitterness and astringency.
Main Methods:
- Three grape varieties (Vitis rotundifolia cv. Noble, Vitis vinifer cv. Cabernet Sauvignon, Chambourcin) were subjected to immediate press, hot press, and skin contact (7 and 14 days).
- Phenolic compounds were quantified using High Performance Liquid Chromatography (HPLC).
- Bitterness and astringency were evaluated by a trained sensory panel.
Main Results:
- Vitis rotundifolia wines exhibited higher epicatechin and gallic acid but lower caftaric acid and procyanidins compared to other varieties.
- Vitis rotundifolia wines were perceived as more astringent and bitter.
- Processing treatments differentially affected phenolic content and color across the three grape varieties.
Conclusions:
- Grape variety and processing methods are key determinants of phenolic composition and sensory characteristics in wine.
- Understanding these interactions is vital for optimizing winemaking strategies and achieving desired wine styles.