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, a _w (<0.76a _w) 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 0.55-0.76a _w, inhibition increased with increasing MD content. At a _w > 0.66, the rate of lactose crystallization decreased at increasing MD contents. Different MDs with similar T _g 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.