Calcium d-Saccharate: Aqueous Solubility, Complex Formation, and Stabilization of Supersaturation
Garcia, AC; Vavrusova, M; Skibsted, LH
| HERO ID | 4944151 |
|---|---|
| In Press | No |
| Year | 2016 |
| Title | Calcium d-Saccharate: Aqueous Solubility, Complex Formation, and Stabilization of Supersaturation |
| Authors | Garcia, AC; Vavrusova, M; Skibsted, LH |
| Journal | Journal of Agricultural and Food Chemistry |
| Volume | 64 |
| Issue | 11 |
| Page Numbers | 2352-2360 |
| Abstract | Molar conductivity of saturated aqueous solutions of calcium d-saccharate, used as a stabilizer of beverages fortified with calcium d-gluconate, increases strongly upon dilution, indicating complex formation between calcium and d-saccharate ions, for which, at 25 °C, Kassoc = 1032 ± 80, ΔHassoc° = −34 ± 6 kJ mol–1, and ΔSassoc° = −55 ± 9 J mol–1 K–1, were determined electrochemically. Calcium d-saccharate is sparingly soluble, with a solubility product, Ksp, of (6.17 ± 0.32) × 10–7 at 25 °C, only moderately increasing with the temperature: ΔHsol° = 48 ± 2 kJ mol–1, and ΔSassoc° = 42 ± 7 J mol–1 K–1. Equilibria in supersaturated solutions of calcium d-saccharate seem only to adjust slowly, as seen from calcium activity measurements in calcium d-saccharate solutions made supersaturated by cooling. Solutions formed by isothermal dissolution of calcium d-gluconate in aqueous potassium d-saccharate becomes spontaneously supersaturated with both d-gluconate and d-saccharate calcium salts, from which only calcium d-saccharate slowly precipitates. Calcium d-saccharate is suggested to act as a stabilizer of supersaturated solutions of other calcium hydroxycarboxylates with endothermic complex formation through a heat-induced shift in calcium complex distribution with slow equilibration upon cooling. |
| Doi | 10.1021/acs.jafc.6b00166 |
| Pmid | 26934422 |
| Wosid | WOS:000372854300020 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |