A fluorometric-coupled reaction for the accurate and rapid determination D- and L-lactate and lactose,
galactose in foods is presented. The method was found useful for an accurate determination of these
metabolites in heterogeneous, opaque and colourful foods without pretreatments. Example for the determination
of lactose, galactose, D- and L-lactate in milk, and yogurts and D- and L-lactate in milk, wine and
beer is provided. Unexpectedly, we found that the composition of some commercial bio-yogurts produced
in Israel is not consistent with the classical definition of yogurts. Thus, this method offers rapid
and accurate methodology, which should be particularly valuable in food quality control.