CELL 58 |
| Physico-chemical interactions between tannins and other biopolymers determine part of their biological and technological properties. In aqueous solutions these interactions will be influenced by the self-aggregation of tannins. Knowing that they are soluble in ethanol, the self-aggregation of grape seed tannins was studied in hydro-alcoholic solutions of different ethanol content and ionic strength through physical separation techniques, dynamic light scattering, and small angle neutron and X-ray scattering. Three tannin subpopulations were identified. A small hydrophobic subpopulation, T1, formed metastable colloidal particles for ethanol content below 70%. Another subpopulation, T2, was precipitated in tartrate buffer below 12% ethanol but remained soluble in water acidified with HCl. The last subpopulation, T3, remained soluble at any studied ethanol content and ionic conditions. The thresholds for the formation of colloidal objects and precipitation; the size and internal structure of colloids, and the size and conformation of the dissolved species were determined. |
|
Poster Session
4:00 PM-6:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Sci-Mix
Division of Cellulose & Renewable Materials |