Assessment of enzymatic hydrolysis of lactose in lactose-free milk production - A comparative study using capillary zone electrophoresis and cryoscopy

Abstract

A comparison of the capillary zone electrophoresis under indirect detection at ultraviolet region (CZE-UV) method with the traditional cryoscopic method for lactose hydrolysis process monitoring is proposed. Two different lactose enzymatic hydrolysis processes (in batch and sterile) were assessed. The hydrolysis levels obtained by the CZE-UV method differed statistically from those obtained by cryoscopy, at 95% confidence, showing variations up to 20% at the same time of processing. During sterile hydrolysis, 90% of lactose reduction was detected after 1 h by CZE-UV and after 3 h by cryoscopy. For in batch hydrolysis, the CZE-UV method indicated 50% of lactose hydrolysis after 3 h of processing, while the cryoscopic method did not identify such lactose reduction during the process simulation. Our results demonstrated that CZE-UV method is precise and reliable analytical method, acting as a good alternative for lactose hydrolysis process monitoring.