Thiamin analysis in red wine by fluorescence reverse phase-HPLC

Area of Science:

• Analytical Chemistry
• Food Science
• Nutritional Biochemistry

Background:

• High-performance liquid chromatography (HPLC) with ferricyanide derivatization is a key method for analyzing thiamin vitamers.
• Polyphenolic compounds in red wine interfere with ferricyanide oxidation, hindering accurate thiamin analysis.
• Effective removal of these interfering compounds is crucial for reliable thiamin quantification in red wine.

Purpose of the Study:

• To develop and validate a method for removing polyphenolic interference in red wine for thiamin analysis.
• To assess the efficacy of polyvinylpolypyrrolidone (PVPP) in eliminating phenolic compounds.
• To determine thiamin vitamer concentrations in various red wine varietals.

Main Methods:

• Utilized polyvinylpolypyrrolidone (PVPP) for the effective removal of polyphenolic compounds from red wine samples.
• Employed HPLC with ferricyanide derivatization for the separation and fluorescence detection of thiamin vitamers.
• Validated the method through spike recovery experiments for thiamin, thiamin monophosphate (TMP), and thiamin diphosphate (TDP).

Main Results:

• PVPP completely removed phenolic compounds from red wines, resolving the interference issue.
• Excellent spike recovery rates were achieved: 101% for thiamin, 104% for TMP, and 100% for TDP.
• Merlot wines exhibited the highest total thiamin concentration (29.01 ng/mL), whereas Pinot Noir wines had the lowest (8.27 ng/mL).

Conclusions:

• PVPP is a highly effective agent for removing polyphenolic interference in red wine, enabling accurate thiamin analysis.
• The developed method allows for reliable quantification of thiamin vitamers across diverse red wine types.
• Significant variations in thiamin content exist among red wine varietals, with Merlot being notably richer in thiamin.