A Fourier transform infrared spectroscopy study of wine polysaccharides

Fifteen polysaccharides previously purified from a red wine and whose structures had been characterised were studied by Fourier transform-infrared spectroscopy (FTIR). These polysaccharides are representative of the main families of polysaccharides found in wines: mannoproteins, arabinogalactan-proteins, RG-I and RG-II. The spectra were processed at between 950 and 1850 cm−1. Significant differences were found between the polysaccharide families. The spectra are explained with reference to glycosyl residues, proteic and galacturonic acid compositions.