also found a rapid oxidation of milk fat migrated on the surface as a result of lactose crystallisation from a whey proteins-milk fat matrix.
In other study, Saltmarch, Vaginini-Ferrari & Labuza (1981) found a highest rate of Maillard reaction in a whey powder at 0.44 critical water activity, where the amorphous lactose began to crystallise releasing water, consequently mobilising reactants for the browning reaction.