DEMONSTRATION OF THE PRESENCE OF CELIAC-ACTIVATING GLIADIN-LIKE EPITOPES IN MALTED BARLEY

A peptide B3144, derived after peptic tryptic digestion of alpha-gliadin and corresponding to residues 3-56 from the coeliac-activating domain I, was previously used to produce monoclonal antibodies. A dot immunobinding assay was developed using these antibodies to detect gluten in wheat, rye, barley and oats. The limit of sensitivity of the assay was 1 mu g/ml for unfractionated wheat gliadin and rye prolamins, and 5 mu g/ml for barley and oat prolamins. Extracts of flours from I coeliac non-toxic rice, maize, millet and sorghum gave negative results. Malt, which represents a partial hydrolysate of barley prolamins, was shown to contain the equivalent of 100-200 mg of barley prolamins/100 g of malt. The assay demonstrates the presence of intact epitopes from the coeliac-activating domain I of alpha-gliadins in malted barley, suggesting toxicity.