RT Journal Article
SR Electronic
T1 A Comparison of Methods For Quantifying Oligomeric Proanthocyanidins From Grape Seed Extracts
JF American Journal of Enology and Viticulture
JO Am J Enol Vitic.
FD American Society for Enology and Viticulture
SP 383
OP 389
DO 10.5344/ajev.2000.51.4.383
VO 51
IS 4
A1 Andrew L. Waterhouse
A1 Steve Ignelzi
A1 Joseph R. Shirley
YR 2000
UL http://www.ajevonline.org/content/51/4/383.abstract
AB Grape seed extract (GSE) has become popular in recent years as a nutritional supplement that possesses antioxidant activity. These extracts contain a heterogeneous mixture of monomers, oligomers, and polymers composed of proanthocyanidin (or flavan-3-ol) subunits. The common colorimetric methods for analyzing the procyanidin concentration and/or composition of grape seed extracts and products containing it can give only crude information on the distribution of the sizes of the components. A normal phase HPLC method has proven to be very applicable to analyzing grape seed extract material and products thereof, and monomer, oligomer (2-7 subunits) and polymeric (8-24 subunits, and ∼24+ subunits) fractions can be discriminated. Values ranged from 5% to 30% for monomers, 17% to 63% oliogomers, 11% to 39% polymers and 2% to 50% for the large (24+) polymers. When specific attributes can be defined for particular size fractions, this method can provide the information needed to compare different samples for their relative potential effect.