Octanol–water partition coefficient of glucose, sucrose, and trehalose

Sugar T, °C P log P Glucose 20 (1.5 ± 0.1) × 10 −3 −2.82 ± 0.04 Sucrose 20 (5.0 ± 0.4) × 10 −4 −3.30 ± 0.03 Trehalose 20 (1.71 ± 0.2) × 10 −4 −3.77 ± 0.05 The octanol–water partition coefficients ( P) of glucose, sucrose, and trehalose were measured at temperatures between 5 and 20 °C using an enzymatic method. The measured log P is compared with calculated and experimental data previously reported. In the case of trehalose, the measured log P differs considerably from the theoretically estimated values and agrees with the expected value for a disaccharide. Some methods of assessing the partition coefficients are also analyzed and it is concluded that the atom/fragment contribution method overestimates the hydrophilicity of disaccharides and, probably in a larger extension, that of trisaccharides. The knowledge of P for these sugars is valuable both for basic or applied purposes, including food and biomolecules stabilization.