Journal
FOOD CHEMISTRY
Volume 125, Issue 1, Pages 106-115Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.foodchem.2010.08.045
Keywords
Intermolecular copigmentation; Self-association Malvidin-3-glucoside; Flavonols; Flavan-3-ols; Seed tannin; UV/visible spectroscopy
Funding
- Australia's grapegrowers and winemakers
- Federal Government
- Commonwealth Cooperative Research Centres
- Australian Research Council
- Grape and Wine Research and Development Corp.
Ask authors/readers for more resources
Thermodynamic parameters for intermolecular copigmentation interactions involving malvidin-3-glucoside were determined by UV/visible spectroscopy at wine pH (pH 3.6). These included association constants, enthalpy and entropy changes, which were measured for chlorogenic acid, caffeic acid, quercetin, quercetin-3-glucoside, (-)-epicatechin, (+)-catechin, procyanidin dimer and seed tannin. Quercetin produced the strongest copigment (K-cp = 2900 1300), whilst the addition of glucose at position 3 (quercetin-3-glucoside) reduced its effect by almost 10-fold. Malvidin-3-glucoside self-association (K-D = 3300 300 mol(-1)) was thermodynamically favoured over intermolecular interaction with any of the copigments tested. No colour enhancement due to self-association was observed for malvidin-3-glucoside-derived pigments that cannot enter hydration reactions. In addition, malvidin-3-(6-O-p-coumaryl)glucoside did not show colour enhancement suggesting that the p-coumaryl group prevents self-association. The malvidin-3-glucoside circular dichroism (CD) spectrum was not affected by indicated changes in malvidin-3-glucoside concentration. These observations demonstrate that self-association of malvidin-3-glucoside is more important than copigmentation in young red wine. (C) 2010 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available