| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2003: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2002: ¥1,700,000 (Direct Cost: ¥1,700,000)
|
|---|
| Research Abstract |
Inter-macromolecular interaction of high methoxyl pectins from citrus and apple in various sugar solutions (ribose, mannose, glucose, sucrose, trehalose, and maltose) was investigated through the analysis of the specific viscosity, η _<sp>, excluding the background effect of sugar solutions. With an increase in the sugar concentration, the water activity, Aw, decreased and )η _<sp> increased linearly with a decrease in Aw for all the sugars tested, showing a change in the hydrogen-bonding among pectin molecules. The effect of Aw on η _<sp> was also dependent on the type of the sugar coexisting. The different effect of sugars on the inter-macromolecular interaction was quantitatively evaluated by -d η _<sp>/dAw, which showed a good correlation with aqueous solvent-ordering parameters for sugar solutions in the literature, such as the parameter α determined from the activity coefficient of water, the number of equatorial-OH group in sugar molecular structure, B-coefficients for spin-lattice and spin-spin relaxation in proton NMR, and B-coefficient of viscosity. This suggests that the different effect of sugars on the inter-macromolecular interaction is explained by their different effect on the hydrophobic interactions among pectin molecules through the change in the solvent-ordering.
|
