Proanthocyanidin A2 purification and quantification of American cranberry (Vaccinium macrocarpon Ait.) products.
In this study, five common proanthocyanidin purification techniques were evaluated prior to phloroglucinolysis, followed by HPLC analysis. An optimized purification method was then used to identify and quantify the proanthocyanidins (extension and terminal units of epigallocatechin, catechin, epicatechin, A type trimer, and A type dimer) of commercially available cranberry products (juices, concentrates, tablets, and capsules; n=17). Two size exclusion beads (Toyopearl 4 TSK HW-40C and Sephadex LH-20) were found suitable for proanthocyanidin purification, though proanthocyanidin extension and terminal unit composition was contingent upon the cleanup procedure utilized. These data illustrate that purification methods require consideration prior to conducting any cranberry proanthocyanidin analyses, and have to be accounted for when comparing values between studies. Total proanthocyanidin levels ranged from 11.7 (juice) to 436.4 (tablet) mg/100 mL or 100 g values obtained from Sephadex LH-20 purification, while total anthocyanin levels ranged from 0.54 (juice) to 98.00 (tablet) mg/100 mL or 100 g.