CRYSTALLIZATION OF AMORPHOUS LACTOSE

Crystallization of amorphous lactose was studied at constant water content and at constant relative humidity above glass transition temperature (T(g)). The rate of crystallization was followed using differential scanning calorimetry. Crystallization at constant water content increased the amount of water in the remaining amorphous matrix, which decreased T(g) and accelerated crystallization. At constant relative humidity crystallization proceeded at a rate determined by T - T(g) which increased with crystallinity. Temperature dependence of time to complete crystallization was confirmed to follow Williams-Landel-Ferry (WLF) equation. The results can be used to evaluate diffusion and crystallization kinetics of amorphous carbohydrates.