Extraction and Characterization of Proanthocyanidins from Grape Seeds

Grape seed contains many polyphenolic compounds that have potential health-promoting benefits. Among the- se compounds are proanthocyanidins, also known as condensed tannins, which is a class of flavanols. The basic structural building blocks of flavanols are polyhydroxyflavan-3-ol units linked together by C-C bonds. They are widely distributed in plants but grape seed has very high contents. This study examined extraction and purification technologies for obtain- ing proanthocyanidins from grape seeds and analytical methods and tools for characterizing them. Proanthocyanidins are polyphenolic compounds that can be found in the plant physiology of several plant species, are mainly concentrated in tree barks and outer skins of seeds. Grape seeds are one of the richest sources of proanthocyanidins (2). Public awareness of the antioxidant and free radical-scavenging abilities of these phenolic com- pounds results largely from the potential of these compounds to increase human health in many ways. Reductions in cardi- ovascular disease, cerebrovascular diseases, and cancer mor- tality are just some of the noticeable examples associated with these phenolic compounds (3-5). Recent advances in the field of nutraceuticals have shown that the compounds found in grapes exhibit even more benefits than initially be- lieved. This paper aims at reviewing these compounds found in the anatomy of the grape seeds and current methods of separation and characterization of proanthocyandins.