Comparison of methods for estimating phenolic maturity in grapes: correlation between predicted and obtained...

Area of Science:

• Enology and Viticulture
• Food Chemistry
• Analytical Chemistry

Background:

• Accurate measurement of phenolic maturity in grapes is crucial for wine quality.
• Existing methods for assessing phenolic maturity vary in accuracy, speed, and ease of use.
• Understanding the predictive capabilities of different phenolic maturity assessment methods is essential for winemakers.

Purpose of the Study:

• To evaluate the predictive accuracy of three phenolic maturity assessment methods: Glories, ITV, and Cromoenos.
• To compare the performance of these methods in predicting key wine parameters like color and phenolic composition.
• To identify the most reliable and efficient method for determining grape phenolic maturity.

Main Methods:

• Grapes (Merlot, Cabernet Sauvignon, Grenache, Tempranillo) were harvested at three ripeness levels.
• Grapes were vinified, and phenolic maturity was estimated using Glories, ITV, and Cromoenos methods.
• Wine and extract analyses included color intensity, CIELAB coordinates, anthocyanins (spectrometry/HPLC), and total phenolics.

Main Results:

• The Glories method showed reasonable prediction for color and phenolics but was time-consuming and labor-intensive.
• The Cromoenos method demonstrated comparable or superior prediction of wine color and phenolic composition.
• The ITV method provided adequate results for anthocyanins and total phenolics but was inadequate for color prediction.

Conclusions:

• The Cromoenos method is a faster, easier, and highly effective tool for predicting wine's phenolic and color characteristics.
• The Glories method is a viable but less efficient alternative for phenolic maturity assessment.
• The ITV method is not recommended for predicting wine color, despite its utility for phenolic compound analysis.