Tannin Content in Vitis Species Red Wines Quantified Using Three Analytical Methods

Area of Science:

• Enology
• Analytical Chemistry
• Viticulture

Background:

• Tannin content significantly influences red wine astringency and quality.
• Accurate tannin quantification remains a key challenge in wine analysis.
• Cold-hardy hybrid grapes present unique analytical challenges due to their composition.

Purpose of the Study:

• To compare tannin quantification in commercial red wines using three analytical methods.
• To evaluate the suitability of protein precipitation (PP) and methylcellulose precipitation (MCP) methods against HPLC-DAD.
• To assess tannin levels in Vitis vinifera and cold-hardy hybrid red wines (Marquette, Frontenac, Petite Pearl).

Main Methods:

• Comparative analysis of tannin quantification using Protein Precipitation (PP), Methylcellulose Precipitation (MCP), and High-Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD).
• HPLC-DAD method based on hydrophobic surface interaction (RPC) was used as a reference.
• Analysis of commercial red wines from Vitis vinifera (Cabernet Sauvignon) and cold-hardy hybrids.

Main Results:

• Cabernet Sauvignon wines exhibited the highest tannin content, while Frontenac wines had the lowest across all methods.
• Marquette wines showed higher tannin content, potentially linked to seed extraction and high alcohol levels.
• PP and MCP methods were found unsuitable for cold-hardy wines due to high quantification limits and anthocyanin interference.

Conclusions:

• The HPLC-DAD (RPC) method is a relevant and reliable technique for quantifying tannins in red wines, including cold-hardy varieties.
• Protein precipitation and methylcellulose precipitation methods are not recommended for tannin analysis in cold-hardy red wines.
• Understanding tannin profiles is crucial for optimizing wine quality and varietal selection.