RATES OF CRYSTALLIZATION OF DRIED LACTOSE-SUCROSE MIXTURES

The isothermal crystallization kinetics of glassy lactose/sucrose mixtures were studied at several storage temperatures (close to T-g and T-m). The kinetic parameters implicit in the Avrami equation were determined. Activation energies for transport (E(D)) and surface nucleation (W*) were also found and correlated to the molar composition of the lactose/sucrose mixtures. A monotonic increase in the half crystallization time (t(1/2)), Avrami index (n), % crystallization per day, activation energy for transport (E(D)) and surface nucleation energy (W*) and a decrease in the crystallization velocity constants (K) were related to the increase in the lactose content of lactose/sucrose mixtures.