DETERMINATION OF FUROSINE IN PASTEURIZED MILK BY USE OF ION-PAIR REVERSED-PHASE LIQUID-CHROMATOGRAPHY

Levels of the furosine content were determined in commercial pasteurized milk samples by use of ion-pair reversed-phase chromatography. Furosine is generated hydrolytically from protein-bound epsilon-lactulosyllysine which is the main chemical intermediate in the early stages of the Maillard reaction. The furosine content in thermally untreated milk ranges from 3 to 5 mg/g protein; values between 6.0 and 7.3 were found in this study in peroxidase-positive pasteurized milk for which a limit of 8 mg furosine/100 g protein is actually discussed in the European Union. Higher levels of furosine in pasteurized milk might be caused by addition of certain amounts of highly heat treated and/or reconstituted milk.