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

Area of Science:

• Food Science
• Cereal Chemistry
• Immunology

Background:

• Gluten proteins are complex, and their structure influences digestibility and immunogenicity.
• Celiac disease is an autoimmune disorder triggered by gluten ingestion.
• Processing methods can alter gluten structure, potentially affecting its immunogenicity.

Purpose of the Study:

• To investigate the impact of extrusion, oven, and microwave treatments on the physicochemical and immunochemical properties of Brazilian wheat flour gluten.
• To assess the in vitro digestibility and the reduction of celiac disease-related epitopes in treated wheat flour.

Main Methods:

• Wheat flour was subjected to extrusion, oven, and microwave processing.
• Analysis included protein solubility, monomeric and polymeric protein content, and glutenin/gliadin profiles.
• In vitro digestibility and quantification of celiac disease immune-stimulatory epitopes using G12 and R5 ELISAs were performed.

Main Results:

• All treatments significantly decreased soluble proteins and increased insoluble proteins, indicating altered gluten structure.
• Treatments affected glutenin and gliadin profiles, with a decrease in α/β-gliadin but no change in γ-gliadin.
• Oven and microwave treatments reduced epitopes detected by G12 ELISA, but R5 ELISA showed no change; overall epitope levels remained high.

Conclusions:

• Extrusion, oven, and microwave treatments modify wheat gluten structure and protein solubility.
• While some reduction in specific immune-stimulatory epitopes was observed, the treatments were insufficient to make the flour safe for individuals with celiac disease.
• Further research is needed to develop processing strategies that effectively eliminate or neutralize immunotoxic gluten epitopes.