Proanthocyanidins are naturally occurring compounds
and are widely found in fruits, vegetables, flowers, bark,
and seeds. They are a class of phenolic compounds
that take the form of oligomers or polymers of polyhydroxy
flavan-3-ol units, such as (þ)-catechin and
(−)-epicatechin [1]. Proanthocyanidins are antioxidants
and free radical scavengers which have preventive
effects on cancers or anti-carcinogenic activities [2–5].
Health promoting effects of proanthocyanidins are due
to their remarkably high scavenging activities [6, 7].
Human consumption of proanthocyanidins is increasing
because of the increased awareness on their potential
value as a health promoting agent. Pomegranates are
cultivated and consumed in large quantities in China
and contain substantial amounts of proanthocyanidins
[8, 9]. They are popularly consumed as fresh fruit, beverages
(juice and wine), and other food products (jams
and jellies). Processing of one ton of fresh pomegranate
fruit generates about 669 kg of by-products, containing
78% of peel and 22% of seeds [10, 11]. The chromatographic
profiles of pomegranate peel extract showed
that pomegranate peel had a high level of proanthocyanidins
[12]. Therefore, pomegranate peel has a great
potential to be used for producing natural proanthocyanidins
which could be used as safe food additives or
nutraceuticals.