Solubility of Xylose, Mannose, Maltose Monohydrate, and Trehalose Dihydrate in Ethanol–Water Solutions

Abstract

The solubilities of (2R,3S,4R)-2,3,4,5-tetrahydroxypentanal (xylose), (2R,3R,4R,5R)-2,3,5,6-tetrahydroxy-4-[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyhexanal hydrate (maltose monohydrate), (2R,3S,4S,5R,6R)-2-(hydroxymethyl)-6-[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxane-3,4,5-triol dihydrate (trehalose dihydrate), and (3S,4S,5S,6R)-6-(hydroxymethyl)oxane-2,3,4,5-tetrol (mannose) in the mixtures of ethanol and water from (278.2 to 298.2) K were determined. The solubilities of all the four saccharides in ethanol–water mixtures increased as equilibrium temperature increased. The solubilities of trehalose dihydrate, xylose, and mannose decreased as ethanol mass fraction in the mixed solvent increased. Maltose monohydrate solubility decreased when ethanol mass fraction in the mixed solvent was less than 0.9. The solubilities of xylose and mannose were predicted with A-UNIFAC, and the average relative deviations (ARD) values were less than 22 %. The solubilities of maltose monohydrate and trehalose dihydrate were calculated with the modified UNIQUAC model. New interaction parameters were calibrated. The ARD values for trehalose dihydrate solubility and maltose monohydrate solubility are 28.6 % and 17.9 %, respectively.