Potential Implication of the Freezing Point Depression by Enzymatic Hydrolysis of Lactose in Milk

Abstract

The. potential problem of detecting added water in lactose-hydrolyzed milk by cryoscopic examination was investigated. The extent to which hydrolysis of lactose corresponded with a given freezing point was calculated and tested experimentally. Cryoscopic measurements were related to the percent of lactose hydrolyzed in milk. Hydrolyzed milks readjusted to normal freezing points with added water were examined by lactometer and sensory evaluations. Although such milk adulterated with up to 25% added water could escape detection by either cryoscopic or sensory evaluations, the Quevenne lactometer could detect 10% added water.