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.