Effect of carboxymethyl cellulose on tartrate salt, protein and colour stability of red wine

Abstract

Background and Aims Recent studies have confirmed a long-term effect of carboxymethyl cellulose (CMC) for tartrate salt stabilisation in white wine. It has been argued that CMC is not only less effective in red wine but also interacts with proteins and polyphenols generating turbidity and change in colour. In order to explain these effects, we studied in detail the impact of CMC on haze formation and colour stability of red wine. Methods and Results The influence of CMC concentration was tested with ten samples of red wine produced from several grape cultivars. The haze-forming material was analysed by sodium dodecyl-sulfate polyacrylamide electrophoresis and the protein composition by high-performance liquid chromatography-mass spectrometry. Colour alteration was documented by Vis-spectroscopy. Three samples of wine that were tested developed significant turbidity when treated with oenological doses of CMC. The haze formation coincided with a high-colour density and protein instability of the wine. The insoluble fraction contained pathogenesis-related wine proteins (thaumatin-like proteins, lipid transfer protein) and was associated with colouring matter. Conclusions Carboxymethyl cellulose is of value for tartrate salt stabilisation in red wine. Occasionally, it promotes development of protein haze and colour loss. At a first glance, this behaviour appears to limit the oenological suitability of CMC, but it might also be considered as a new tool to remove unstable wine proteins. Significance of the Study The results indicate the conditions under which red wine turbidity is triggered by CMC. Thus, they are important for the elaboration of recommendations for the optimal use of the polymer.