LACTOSE SOLUBILITY AND CRYSTAL-GROWTH AS AFFECTED BY MINERAL IMPURITIES

Single crystal growth method was applied to determine lactose solubili ty, growth rate and morphology of lactose crystals grown in model lact ose solutions containing various salts and in whey ultrafiltration (UF ) permeate solutions. Salts either increased or decreased the lactose crystal growth rate, due to effects on lactose solubility. Addition of LiCl led to a maximum increase in growth rate and a maximum decrease in lactose solubility, while K2HPO4 had opposite effects. Growth rates of individual lactose crystals in whey UF permeate solutions were low er and lactose solubility higher than those in pure lactose solutions.