Specific Detection of the Amadori Compounds in Milk by Using Polyclonal Antibodies Raised against a Lactosylated Peptide

Polyclonal antibodies raised against synthetic lactosylated peptide were found to be specifically directed against the carbohydrate moiety of the immunogen, recognizing, in addition to the Amadori compound, lactulose and, to a lesser extent, lactose and galactose. These antibodies were effective in detecting lactosylated proteins both on a model system containing ?-casein and on milk subjected to different thermal treatments. Widespread lactosylation of the protein components was found in UHT-treated and sterilized milk, whereas it was very limited in raw and pasteurized milk. The index of lactosylation determined by competitive ELISA tests was linearly correlated to the furosine content of milk samples treated within 60 and 100 °C. This ELISA-based procedure is recommended for rapid monitoring of raw milk processing and extension.