Additivity of water sorption, alpha-relaxations and crystallization inhibition in lactose–maltodextrin systems

Water sorption of lactose–maltodextrin (MD) systems, structural relaxations and lactose crystallization were studied. Accurate water sorption data for non-crystalline lactose previously not available over a wide range of water activity, aw (<0.76aw) were derived from lactose–MD systems data. Structural relaxations and crystallization of lactose in lactose–maltodextrin (MD) systems were strongly affected by water and MD. At high MD contents, inhibition of crystallization was significant. Inhibition with a high dextrose equivalent (DE) MD was more pronounced possibly because of molecular number and size effects. At 0.55–0.76aw, inhibition increased with increasing MD content. At aw > 0.66, the rate of lactose crystallization decreased at increasing MD contents. Different MDs with similar Tg in lactose–MD systems showed different crystallization inhibition effects. The results of the present study showed that the DE in selection of MD for applications has important effects on component crystallization characteristics.