Immunological appraisal of modified gluten to trim down celiac toxicity

Abstract

The aim of the present research was to modify wheat gluten by binding methionine to gluten proteins to develop bread for celiac disease (CD) patients. The highest protein content, wet gluten content, dry gluten content and sodium dodecyl sulphate-sedimentation value were shown by the wheat variety AARI-11, therefore, it was selected for gluten modification. The bound methionine to gluten proteins was found increasing along the reaction time as the reaction proceeds and at a maximum near to 60 minutes and then it starts decreasing. The lowest immunoreactivity of the modified gluten was obtained near to 60 min of reaction at pH 10. The results for immunoglobulin A (IgA) index showed that the serum of each patient had positive IgA index to gliadins from unmodified gluten, but just sera of two patients had positive IgA index to gliadins from modified gluten and when these proteins were digested, the sera of no patient's serum had positive IgA reactivity. Among physical characteristics of breads 2 hours after baking, the specific volume of the modified gluten containing bread (4.13 ± 0.14 cm3/g) was lower than the control bread (4.59 ± 0.21 cm3/g). However, bread made with modified gluten had higher specific volumes than other gluten-free breads. Texture of the modified gluten was also affected by modification. Finally, the gluten content in the modified gluten bread was 79 ppm which is under the limits set by the Codex Alimentarius for food with reduced gluten content should have from 20 to 100 ppm. The study concludes that the incorporation of steric immensity into gluten proteins in order to shun immune recognition is the most promising approach to acquire wheat-based products that are tolerated by CD patients.