D- and L-lactate determination in dairy products: presentation of a fast automated analysis system.
A flow-injection system is presented, which is versatile, automated and has an integrated enzyme system. Its efficiency at determining D- and L-lactate separately in dairy products is compared with the officially used reference method (DIN 10335). By means of a mathematical elimination of matrix effects, the pretreatment steps can be clearly reduced. As a result of the immobilization of the enzymes, an appropriate automation software and an adaptation of the system developed to the given medium, the analysis could be performed within 5 min and was distinctly cheaper than alternative methods. The values determined in 15 different dairy products deviated from those of the reference method by 3% at a maximum.
Becker
T
T
Lehrstuhl für Allgemeine Chemie und Biochemie, Technische Universität München, Freising-Weihenstephan, Germany.
Schmidt
H L
HL
Lechner
E
E
D000818:Animals; D001322:Autoanalysis / Q000295:instrumentation / Q000379:methods; D002079:Butter / Q000032:analysis; D003611:Dairy Products / Q000032:analysis*; D004800:Enzymes, Immobilized; D007770:L-Lactate Dehydrogenase; D007773:Lactates / Q000032:analysis*; D007934:Leuconostoc / Q000201:enzymology; D008892:Milk / Q000737:chemistry*; D012016:Reference Values; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D015014:Yogurt / Q000032:analysis
D004800:Enzymes, Immobilized; D007773:Lactates; D002079:Butter; D007770:L-Lactate Dehydrogenase