The colloidal stabilization of young red wine by Acacia senegal gum: The involvement of the protein backbone from the protein-rich arabinogalactan-proteins

The role of Arabic gum on astringency by modulating the polyphenol fraction-protein reaction in model wine

The potential contribution of Arabic gum to wine astringency was discussed in this study. Two universally used Arabic gum (concentration of 0.2-1.2 g/L) were investigated in model wine based on the polyphenol fractions (phenolic acids, monomeric/oligomeric, and polymeric procyanidin) and protein interaction system. Both physicochemical analyses and sensory evaluation revealed that the modulation of Arabic gum on astringency was affected by the structural properties and concentration of Arabic gum and polyphenolic fractions. Arabic gum at 0.2 g/L appeared as the optimal dose to reduce astringency compared to 0.6 and 1.2 g/L. It inhibited astringency induced by polymeric procyanidin more than that of oligomeric procyanidins and phenolic acids mainly by forming soluble ternary complexes with polyphenols and proteins, and preferentially binding proteins/polyphenols to decrease polyphenol-protein reactions. Arabic gum also inhibited the self-aggregation of polyphenols, exhibiting more binding sites when its higher molecular weight and more/longer branches, leading to competition with polyphenols for bind proteins.

Acacia gums new fractions and sparkling base wines: How their biochemical and structural properties impact foamability?

Foam is the first attribute observed when sparkling wine is served. Bentonite is essentially used to flocculate particles in sparkling base wines but can impair their foamability. Gums from Acacia senegal and Acacia seyal improved the foamability of different bentonite-treated base wines. Our main goal was to see how the supplementation with new fractions separated from Acacia gums by Ion Exchange Chromatography affected foamability of sparkling base wines, deepening the relation between foam behavior and characteristics of wine and gums. High molar mass fractions increased the maximal foam height and the foam height during the stability period in, respectively, 11 out and 8 out of 16 cases (69% and 50%, respectively). The properties of the supplementing gums fractions obtained by IEC and, although to a minor extent, the wine characteristics, affected positively and/or negatively the foam behavior. Wine foamability also depended on the relationship between wine and gums fractions properties.

Evaluating Alternatives to Cold Stabilization in Wineries: The Use of Carboxymethyl Cellulose, Potassium Polyaspartate, Electrodialysis and Ion Exchange Resins

The tartaric stabilization of wines before bottling to avoid the precipitation of tartaric acid salts is an important and common step during wine production. The presence of precipitated salt crystals in bottled wines is detrimental to their quality and can even be a legal issue in some countries. Different methodologies are used in wineries to substitute the classical low-temperature stabilization process, which is an effective but costly process. This study comprises two years of experiments with red wines at an industrial scale. In the first year of the experiment, two subtractive methods (ionic exchange resins and electrodialysis) were tested, whereas two additive methods (potassium polyaspartate and carboxymethyl cellulose, both of them containing gum Arabic) were tested the second year. The tartaric stability of the wines, together with the oenological, chromatic and sensory characteristics, were followed during one year in the bottle. The results indicate that carboxymethyl cellulose and potassium polyaspartate (both combined with gum Arabic) were best at maintaining the sensory and chromatic characteristics during storage, with potassium polyaspartate providing a good tartaric stability to the treated wine and this wine being, in general, preferred in a sensory analysis test.