The mouth-feel properties of polysaccharides and anthocyanins in a wine like medium

Two fractions containing the major polysaccharides present in wine were isolated, one comprising a mixture of neutral polysaccharides, mannoproteins and arabinogalactan-proteins, and the other containing the acidic polysaccharide, rhamnogalacturonan II. A grape anthocyanin fraction was also prepared. A trained sensory panel, using formal sensory descriptive analysis methods to rate the intensity of mouthfeel attributes while the samples were held in the mouth and after expectoration, individually assessed the fractions, dissolved in a model wine at levels commonly encountered in red wines. Both polysaccharide fractions significantly increased the ‘fullness’ sensation above that of the base wine. The rhamnogalacturonan II fraction significantly decreased the attribute ratings associated with the astringency of the model wine whereas the neutral wine polysaccharide fraction had less affect on reducing the ratings for these attributes. The anthocyanin fraction tended to increase ‘fullness’ although the effect was not great enough to be statistically significant. Unlike the polysaccharides, this fraction also increased perceived astringency but this effect could be due to the presence of some derived tannins in the sample.