A New Approach for Quantifying Purpurogallin in Brewed Beverages Using LC-MS in Combination with Solid Phase...

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Spectrometry

Background:

• Purpurogallin (PPG) is a potent antioxidant found in plant-based foods.
• Its hydrophobicity complicates direct quantification in brewed beverages.
• A reliable method for PPG determination in beverages is needed.

Purpose of the Study:

• To develop a method for detecting and quantifying purpurogallin (PPG) in brewed beverages.
• To compare different extraction techniques for PPG analysis.
• To determine PPG content in commercial coffee, cocoa, and tea.

Main Methods:

• Solid-phase extraction (SPE) coupled with liquid chromatography-mass spectrometry (LC-MS).
• Comparison of acetonitrile extraction (ANE), water extraction (WTE), and moka pot brewing (MPB).
• Quantification of PPG in commercial coffee, tea, and cocoa samples.

Main Results:

• The developed LC-MS method achieved limits of detection and quantification of 71.8 and 155.6 ng/g dry weight (dw), respectively.
• Water extraction (WTE) demonstrated better correlation with moka pot brewing (MPB) compared to acetonitrile extraction (ANE).
• PPG was detected in coffee and tea, with highest levels found using ANE, but WTE is recommended for beverage analysis.

Conclusions:

• Water extraction (WTE) is the most suitable method for determining purpurogallin (PPG) in brewed beverages.
• Purpurogallin (PPG) is present in significant amounts in brewed coffee.
• The developed SPE-LC-MS method enables industrial applications and future research on PPG in beverages.