Growth morphology of sucrose crystals. The role of glucose and fructose as habit-modifiers

The influence of glucose (G) and fructose (F) on the habit of sucrose crystals were analysed through stereochemical compatibility between their molecules and surface sites of the crystal. First neighbour interactions (H-bondings) and the terrace-ledge-kink (TLK) surface model are adopted. Notwithstanding the simple qualitative model, this method of analysis appears to be satisfactory to account for the preferential adsorption upon specific crystal forms. A more complex model for adsorption in the kink sites, together with the behaviour as disruption tailor-made additives are proposed for both G and F, to highlight why high concentrations are needed to induce macroscopic habit variations. X-powder diffractometry shows the systematic effect of the impurities on the bulk structure of the sucrose crystal.