Influence of Wine Pectic Polysaccharides on the Interactions between Condensed Tannins and Salivary Proteins

• Published in: Journal of agricultural and food chemistry 2006-11, Vol.54 (23), p.8936-8944
• Main Authors: Carvalho, Elisabete, Mateus, Nuno, Plet, Benoit, Pianet, Isabelle, Dufourc, Erick, De Freitas, Victor
• Format: Article
• Language: English
• Subjects: alpha-amylase; alpha-Amylases - chemistry; Amino Acid Sequence; animal proteins; arabinogalactans; Biological and medical sciences; chemical reactions; Chemical Sciences; Fermented food industries; Food industries; Fundamental and applied biological sciences. Psychology; grape seeds; ionic strength; Light; Molecular Sequence Data; pectins; Pectins - chemistry; Peptides - chemistry; Polysaccharides - chemistry; proanthocyanidins; Proline-Rich Protein Domains; proline-rich proteins; protein aggregates; rhamnogalacturonan II; saliva; Salivary Proteins and Peptides - chemistry; Scattering, Radiation; Seeds - chemistry; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tannins - chemistry; Vitis - chemistry; Wine; wines; Wines and vinegars
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf061835h

α-Amylase, a major human salivary protein, and IB8c, a representative of the proline-rich proteins, were obtained by isolation from saliva and by solid-phase synthesis, respectively. The interactions between these proteins and condensed tannins isolated from grape seeds were studied at different protein and tannin concentrations by measuring their aggregation. Pectic polysaccharides were isolated from wine, and their effect on protein tannin aggregation was assessed. The results presented in this study showed that the most acidic fractions of arabinogalactan proteins have the ability to inhibit the formation of aggregates between the grape seed tannins and the two different salivary proteins. Rhamnogalacturonan II has the same ability toward α-amylase but not IB8c under the conditions of the present study. Polysaccharides show effects at concentrations at which they are present in wine, which could mean an influence in wine astringency. The interaction between condensed tannins and α-amylase is differently affected by ionic strength when compared with IB8c. Keywords: Wine polysaccharides; condensed tannins; human salivary proteins; protein−tannin interaction, ionic strength