Abstract
The quantitative and qualitative impacts of anthocyanins on proanthocyanidin adsorption to grape-derived cell wall material were investigated in fifteen unique systems of varying temperatures, ethanol concentrations, and proanthocyanidin concentrations. Proanthocyanidin solutions were exposed to cell wall material and monitored for changes in concentration over 24 h. Increases in both temperature and ethanol resulted in a larger retention of proanthocyanidins in solution and typically faster adsorption kinetics. Analysis of the solution after exposure to cell wall revealed a significant reduction in the molecular weight of proanthocyanidins present in solution, suggesting that anthocyanins do not alter a previously described mechanism of preferentially binding large molecular weight molecules. Additionally, a reduction in polymeric pigment abundance was noted in most conditions, suggesting rapid formation of polymeric pigment in the model solution and preferential adsorption of the polymeric pigment to cell wall material. Compared to a previous study of proanthocyanidin adsorption in the absence of anthocyanins, a significantly larger percentage of proanthocyanidin material was lost via adsorption—up to 70% of available material. In a winemaking context, this may suggest a preferential loss of polymeric pigment via adsorption to cap cell wall material compared to non-pigmented proanthocyanidins and free anthocyanins.
Description
This article is published by MDPI and is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Publisher
MDPI
Date of publication
9-10-2020
Language
english
Persistent identifier
http://hdl.handle.net/10950/4312
Document Type
Article
Recommended Citation
Beaver, Jordan W.; Miller, Konrad V.; Medina-Plaza, Cristina; Dokoozlian, Nick; Ponangi, R.; Blair, T.; Block, D.; and Oberholster, A., "The effects of temperature and ethanol on proanthocyanidin adsorption to grape cell wall material in the presence of anthocyanins" (2020). Chemistry Faculty Publications and Presentations. Paper 3.
http://hdl.handle.net/10950/4312