Enhanced NMR-based profiling of polyphenols in commercially available grape juices using solid-phase extraction

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Biochemistry

Background:

• Grape polyphenols offer significant health benefits, including cardiovascular protection.
• Characterizing diverse polyphenols in grapes and juices is challenging due to complex matrices.
• Proton nuclear magnetic resonance ((1)H NMR) spectroscopy is a promising tool for polyphenol profiling.

Purpose of the Study:

• To develop an improved extraction method for grape juice analysis.
• To enhance the detection and identification of polyphenols using (1)H NMR spectroscopy.
• To overcome limitations posed by carbohydrate interference in spectral analysis.

Main Methods:

• Development of a selective extraction technique for grape juice.
• Application of (1)H NMR spectroscopy for polyphenol profiling.
• Comparative analysis of spectra before and after extraction.

Main Results:

• The developed extraction method significantly reduced carbohydrate signals.
• Spectral overlap was minimized, increasing the dynamic range of the (1)H NMR spectra.
• A greater number of polyphenols were detected and potentially identifiable post-extraction.

Conclusions:

• The novel extraction method enhances the utility of (1)H NMR for grape polyphenol analysis.
• This approach facilitates more comprehensive characterization of bioactive compounds in grape products.
• Improved polyphenol identification contributes to understanding their health benefits.