New insights into wheat toxicity: Breeding did not seem to contribute to a prevalence of potential celiac disease’s immunostimulatory epitopes

• Published in: Food chemistry 2016-12, Vol.213, p.8-18
• Main Authors: Ribeiro, Miguel, Rodriguez-Quijano, Marta, Nunes, Fernando M., Carrillo, Jose Maria, Branlard, Gérard, Igrejas, Gilberto
• Format: Article
• Language: English
• Subjects: Celiac disease; Celiac Disease - immunology; Chromatography, High Pressure Liquid; Enzyme-Linked Immunosorbent Assay; Epitopes - chemistry; Food Technology; Gliadin - chemistry; Gliadins; Gluten; Glutens - immunology; Hot Temperature; Humans; Life Sciences; Plant Breeding; Prevalence; RP-HPLC; Tetraploidy; Toxic epitopes; Triticum - genetics; Triticum - immunology
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2016.06.043

•Breeding did not seem to contribute to higher levels of immunostimulatory epitopes.•High inter-varieties heterogeneity concerning immunostimulatory epitopes was found.•Toxic epitopes: Spelt>Wheat landraces>Modern wheat varieties=Tetraploid varieties.•ω-Gliadins content explain 40% of toxic epitopes variation in tetraploid varieties.•α/β, ω1,2, ω5-gliadins content showed discrimination potential for ploidy analysis. Gluten proteins, namely gliadins, are the primary trigger of the abnormal immune response in celiac disease. It has been hypothesised that modern wheat breeding practices may have contributed to the increase in celiac disease prevalence during the latter half of the 20th century. Our results do not support this hypothesis as Triticum aestivum spp. vulgare landraces, which were not subjected to breeding practices, presented higher amounts of potential celiac disease’s immunostimulatory epitopes when compared to modern varieties. Furthermore, high variation between wheat varieties concerning the toxic epitopes amount was observed. We carried out quantitative analysis of gliadin types by RP-HPLC to verify its correlation with the amount of toxic epitopes: ω-type gliadins content explain about 40% of the variation of toxic epitopes in tetraploid wheat varieties. This research provides new insights regarding wheat toxicity and into the controversial idea that human practices may have conducted to an increased exposure to toxic epitopes.