Protein Quality and IgE-Binding in Ancient and Modern Wheat: An Analytical Study

Ancient wheat materials are increasingly used in cereal-based products because of their perceived nutritional advantages and distinctive protein composition. However, their protein quality and IgE-binding properties after processing remain insufficiently characterized. This study evaluated total protein content, essential amino acid composition, ELISA-detectable gliadin content, and IgE-binding patterns in flours and corresponding pasta products prepared from eight industry-sourced ancient and modern wheat materials, including einkorn, emmer, Kamut, spelt, round grain wheat, wheat 2Ab, common wheat, and durum wheat. Protein content was determined by the Kjeldahl method, amino acid composition by UHPLC, gliadin content by direct ELISA, and IgE-binding properties by slot blot analysis using sera from allergic individuals. The analysed wheat materials differed markedly in protein content, amino acid profile, gliadin detectability, and IgE-binding capacity. Spelt and Kamut showed the highest total protein contents, while selected ancient wheat materials, particularly emmer, Kamut, and einkorn, exhibited more favourable scores for some essential amino acids than common wheat and durum wheat. Nevertheless, none of the analysed materials fully met the FAO/WHO reference pattern for all evaluated essential amino acids, with lysine and histidine remaining the main limiting amino acids. Einkorn flour showed the highest ELISA-detectable gliadin content, consistent with its distinctive gluten protein composition. Processing into pasta reduced ELISA-detectable gliadin levels in all analysed materials, indicating processing-related changes in protein extractability and epitope accessibility. Despite reduced gliadin detectability after processing, IgE-reactive components remained detectable in both flour and pasta extracts. IgE-binding patterns were strongly dependent on wheat material, product form, and individual serum profile. Kamut pasta repeatedly showed one of the strongest IgE-binding responses across different sera, indicating that processing did not eliminate IgE-reactive components in this material. These findings demonstrate that selected ancient wheat materials may offer favourable protein-related nutritional characteristics, but these features should not be interpreted as evidence of reduced IgE-binding capacity. Integrated assessment of protein quality, gliadin detectability, and IgE-binding properties is therefore necessary for a more complete evaluation of ancient and modern wheat-based products.