MATRIX-ASSISTED LASER DESORPTION IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRIC MICROANALYSIS - THE FIRST NONIMMUNOLOGICAL ALTERNATIVE ATTEMPT TO QUANTIFY GLUTEN GLIADINS IN FOOD SAMPLES/

The first epitope-independent procedure for rapidly quantifying gluten gliadins in food by matrix-assisted laser desorption/ionization time- of-flight mass spectrometry (MALDI/TOF-MS) based on the direct observa tion of the characteristic gliadin mass pattern is presented. This pat tern was identified in both processed and unprocessed gluten-containin g food samples. The procedure allows; the micro-quantification of glut en int food samples below levels toxic far coeliac patients, with a li near response in the 0.4-10 mg per 100g range and a high detection sen sitivity similar to that of enzyme-linked immunosorbent assay (ELISA) systems, Food samples simultaneously analyzed Lay MALDI/TOF-MS and a h ighly sensitive laboratory-made sandwich ELISA revealed a good correla tion between the two techniques, In addition, MALDI/TOF-MS provides a rapid screening system to determine the presence af gliadins in food s amples by directly monitoring the occurrence of the protonated gliadin mass pattern, The procedure also permits the study of the alteration of gliadins in food during the baking: process,providing data on the b eat effect by changes in protein mass signals. (C) 1997 by John Wiley & Sons Ltd.