Characterization of grape procyanidins using high-performance liquid chromatography/mass spectrometry and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

High-performance liquid chromatography/mass spectrometry (HPLC/MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to characterize the procyanidin composition of the grape seed extract. The detection of the oligomers composed of (+)-catechin, (-)-epicatechin, and their galloylated derivatives in the grape seeds is demonstrated. With MALDI-TOF MS, oligomers up to nonamers were observed. The potential of the MALDI-TOF MS technique as a quantification tool is also discussed. The information presented in this study could lead to the determination of procyanidin content and their molecular weight distribution in grape seeds.