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Updated: Jun 26, 2026

A Generalized Method for Determining Free Soluble Phenolic Acid Composition and Antioxidant Capacity of Cereals and Legumes
Published on: June 10, 2022
Determination of proanthocyanidin A2 content in phenolic polymer isolates by reversed-phase high-performance liquid
Jayma L Koerner1, Victor L Hsu, Jungmin Lee
1Department of Food Science and Technology, Oregon State University, Corvallis, OR 97331, USA.
Abstract:
This article summarizes the development of an analytical method for the determination of proanthocyanidin (PAC) A2 in phenolic polymer isolates following acid-catalyzed degradation in the presence of excess phloroglucinol. Isolates from concentrated cranberry juice (CCJ) were extensively characterized and molar extinction coefficients were determined for the terminal A2 and phloroglucinol adduct of the extension A2 unit. Peanuts were also found to contain both extension and terminal A-type PACs and therefore a total peanut system (TPS) was chosen to test the effectiveness of the HPLC method that was developed with the CCJ system. Kinetic studies were conducted and reaction conditions were optimized for the A2 units in both CCJ and TPS. The optimized method provides quantitative and reproducible information on the A2 content of proanthocyanidin isolates.
