Modelling ice growth and inclusion behaviour of sucrose and proteins during progressive freeze concentration

摘要

This study focused on modelling ice growth and solute inclusion behaviour during progressive freeze concentration of sucrose, soy protein, and whey protein. Experiments were conducted in a small stirred tank set-up and ice growth was modelled using mass and heat balances. Solute inclusion was estimated using an intrinsic distribution coefficient. For sucrose solutions, the intrinsic distribution coefficient is proposed dependent on the initial and critical concentrations, where the last is related to the fast increase in viscosity and decrease in diffusivity when the solution approaches glass transition. Predictions were found in agreement with experimental data, except when dendritic ice growth was observed. Solutions of whey and soy proteins behaved differently due to their large difference in solubility. These proteins also showed different inclusion behaviour compared to sucrose, due to lower freezing point depression and lower concentrations far away from glass transition.