Identification of allergenic milk proteins markers in fined wines by capillary liquid chromatography-electrospray ionization-tandem mass spectrometry.

A method based on capillary liquid chromatography combined with electrospray ionization-tandem mass spectrometry (CapLC-ESI-MS-MS) for the detection and identification of casein deriving peptides in fined white wine is described. This is the first step towards the development of a liquid chromatography mass spectrometric method for the detection/identification of markers of potentially allergenic milk proteins used as wine fining agents. The method demonstrated to be capable of detecting some peptides arising from alpha and beta casein (with the relative aminoacidic sequences elucidated) in extracts of white wine fined with casein at 100 and 1000 mu g/mL. This MS based approach appears to be a useful tool for screening purposes as well as a confirmatory tool for the unequivocal identification of caseins in ELISA positive samples.