Flour Treatments Affect Gluten Protein Extractability, Secondary Structure, and Antibody Reactivity

Commercial Brazilian wheat flour was subjected to extrusion, oven, and microwave treatments. The solubility, monomeric and polymeric proteins, and glutenin and gliadin profiles of gluten were analyzed. In addition, in vitro digestibility and response against potential celiac disease immune-stimulatory epitopes were investigated. All treatments resulted in low solubility of the polymeric and monomeric proteins. The amounts of insoluble proteins increased from 5.6 % in control flour to approximately 10 % for all treatments, whereas soluble proteins decreased from 6.5 % to less than 0.5 % post treatment. In addition, treatments affected glutenin and gliadin pro-files. The amount of α/β- gliadin extracted decreased after all treatments, while that of γ-gliadin was unaffected. Finally, alteration of the gluten structure and complexity was not sufficient to render a product safe for consumption for individuals with celiac disease; the number of poten-tial celiac disease immune-stimulatory epitopes remained high.