D-LACTATE AND L-LACTATE DETERMINATION IN DAIRY-PRODUCTS - PRESENTATION OF A FAST AUTOMATED-ANALYSIS SYSTEM

A flow-injection system is presented, which is versatile, automated an d has an integrated enzyme system. Its efficiency at determining D- an d L-lactate separately in dairy products is compared with the official ly used reference method (DIN 10335). By means of a mathematical elimi nation of matrix effects, the pretreatment steps can be clearly reduce d. As a result of the immobilization of the enzymes, an appropriate au tomation software and an adaptation of the system developed to the giv en medium, the analysis could be performed within 5 min and was distin ctly cheaper than alternative methods. The values determined in 15 dif ferent dairy products deviated from those of the reference method by 3 % at a maximum.