Procyanidin

[6] The seed testas of field beans (Vicia faba) contain procyanidins[7] that affect the digestibility in piglets[8] and could have an inhibitory activity on enzymes.

Procyanidins from field beans (Vicia faba)[12] or barley[13] have been estimated using the vanillin-HCl method, resulting in a red color of the test in the presence of catechin or proanthocyanidins.

The Porter Assay is a chemical test to help determine the potency of procyanidin containing compounds, such as grape seed extract.

Gel permeation chromatography (GPC) analysis allows to separate monomers from larger PCO molecules.

Condensed tannins can undergo acid-catalyzed cleavage in the presence of a nucleophile like phloroglucinol (reaction called phloroglucinolysis), thioglycolic acid (thioglycolysis), benzyl mercaptan or cysteamine (processes called thiolysis[17]) leading to the formation of oligomers that can be further analyzed.

[18] Phloroglucinolysis can be used for instance for procyanidins characterisation in wine[19] or in the grape seed and skin tissues.

[23] Reaction on condensed tannins from Douglas fir bark produces epicatechin and catechin thioglycolates.

[24] Condensed tannins from Lithocarpus glaber leaves have been analysed through acid-catalyzed degradation in the presence of cysteamine.

[26] Pycnogenol is a dietary supplement derived from extracts from maritime pine bark that contains 70% procyanidins, and is marketed with claims it can treat many conditions.