High-Resolution Mass Spectrometry-Based Metabolomics for Increased Grape Juice Metabolite Coverage

Area of Science:

• Enology and Viticulture
• Metabolomics
• Analytical Chemistry

Background:

• Grape juice composition is key to technological ripeness and wine quality.
• Understanding grape flesh metabolites is crucial for enological potential.
• Previous studies focused on whole berries, not solely the flesh.

Purpose of the Study:

• To explore the metabolite coverage in grape flesh juices.
• To analyze the chemical diversity of four Vitis vinifera varieties.
• To assess the potential for discriminating grape juices based on their metabolomic profiles.

Main Methods:

• Non-targeted direct infusion Fourier-transform ion cyclotron resonance mass spectrometry (DI-FT-ICR-MS).
• Reversed-phase ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (RP-UHPLC-Q-ToF-MS).
• Solid-phase extraction (SPE) pretreatment of grape juices.

Main Results:

• Identification of over 4500 elemental compositions, representing tens of thousands of metabolites.
• Significant overlap in chemical diversity across different grape juices, including Pinot noir and Chardonnay.
• Successful discrimination models developed for Chardonnay vs. Pinot noir and Chardonnay vs. Aligoté juices, independent of origin or vintage.

Conclusions:

• Metabolomic analysis provides a holistic molecular description of grape juice.
• This approach reveals commonalities and distinct chemical profiles among grape varieties.
• The findings support the use of metabolomics for understanding enological potential and grape varietal characterization.