SELECTIVE IDENTIFICATION BY MATRIX-ASSISTED-LASER-DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY OF DIFFERENT TYPES OF GLUTEN IN FOODS MADE WITH CEREAL MIXTURES/

The gluten toxic fractions responsible for the mucosal damage in coeli ac disease (CD), so-called gliadins, hordeins, secalins and avenins fr om a large number (30-40) of wheat, barley, rye and oats cultivars res pectively, have been mass analyzed by matrix-assisted laser desorption /ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Gliadin, secalin and avenin characteristic mass profiles are nearly identical a mongst distinct cultivars from the corresponding cereal, while hordein s profiles show more variability depending on the particular barley cu ltivar. On the basis of these four distinguishable characteristic mass patterns spreading within the 20 000-40 000 Da range, MALDI-TOF-MS ha s permitted the direct and simultaneous visualization of gliadins, hor deins, secalins and avenins in foods elaborated with cereal mixtures o f wheat, barley, rye and oats. This capacity has been demonstrated by mass analyzing foods made with these four cereals in varying ratios. T hus MALDI-TOF-MS can be preliminarily established as a unique system w ith the ability to discriminate the specific type of gluten toxic frac tions present in food samples. (C) 1998 Elsevier Science B.V. All righ ts reserved.