Composition of grape skin proanthocyanidins at different stages of berry development

• Author(s): Hayasaka, Y.; Jones, G.; Kennedy, J.; Vidal, S.; Waters, E.;
• Abstract: The composition of grape (Vitis vinifera L. cv. Shiraz) skin proanthocyanidins has been determined at different stages of berry development. Beginning approximately 3 weeks after fruit set and concluding at commercial ripeness,, the composition of isolated skin proanthocyanidins was determined using the following analytical techniques: elemental analysis, UV-Vis absorption spectroscopy, reversed-phase HPLC after acid-catalysis in the presence of excess phloroglucinol, gel permeation chromatography, electrospray ionization mass spectrometry (ESI-MS), and C-13 NMR. On the basis of these analyses, berry development was correlated with an increase in proanthocyanidin mean degree of polymerization, an increase in the proportion of (-)-epigallocatechin extension subunits, and increases in the level of anthocyanins associated with the proanthocyanidin fraction. Additionally, data acquired from ESI-MS of the isolates following acid-catalysis in the, presence of excess phloroglucinol is consistent with pectin-bound proanthocyanidins.
• Publication Date: Nov 2001
• Journal: Journal Of Agricultural And Food Chemistry