Proanthocyanidins Test - Total

Method Description

Proanthocyanidins (PACs) are condensed tannins — chains of flavan-3-ol units linked together — and they're largely responsible for the dry, astringent character of many botanicals and plant-derived products. They're measured because they influence mouthfeel, color stability, and antioxidant capacity in beverages, botanicals, and nutraceuticals, and can support structure/function claims on supplement labels. The DMAC assay uses a reagent called 4-(dimethylamino)cinnamaldehyde, which reacts with a specific reactive site on the flavan-3-ol structure to form a blue-green color measured at ~640 nm; the more intense the color, the more PACs present. DMAC is more selective for flavan-3-ols than broader total-phenolic methods such as Folin–Ciocalteu, though the color response depends on chain length, so results are tied to the specific method and reference standard used. Cambium reports PAC content against a grape seed oligomeric proanthocyanidin (G-PAC) standard; values referenced to other standards, such as the procyanidin A2 used in the BL-DMAC method (AOAC 2019.06), are not directly comparable.