INTEGRATED ANALYTICAL APPROACH TO CHARACTERIZE DURUM WHEAT GENOTYPES COMBINING REDUCED GLUTEN CONTENT AND GOOD RHEOLOGICAL PROPERTIES

Introduction Effective enzymatic gluten detoxification strategies have been developed in the last years; however, obtaining low-gluten wheat products without impairing the rheological properties remains a challenging issue [1]. In this contribution, we presented an integrated analytical approach for the identification of wheat genotypes with reduced toxicity and satisfactory rheological properties [2]. Methods A comprehensive characterization of durum wheat genotypes was performed including grain quality traits (productivity-related and quali-quantitative characteristics) and proteomic profiling (R5-ELISA, HPLC-UV analysis). The data were evaluated statistically, and a selected list of candidates was subjected to in-vitro gastroduodenal digestion [3] and discovery MS/MS analysis for in-silico toxicity risk assessment [4]. Results 38 accessions of Triticum turgidum sp., including both wild and cultivated ones, were investigated. A preliminary profiling of gluten proteins was accomplished on the whole collection focusing on the gliadin fraction as main responsible for immunoreactivity in celiac disease (CD) patients. Complementary information about grain protein content, grain yield per spike, dry gluten and gluten index were collected. Cluster analysis was performed on original variables supporting the proper selection of five genotypes featuring medium and strong gluten strength, together with R5-reactivity and gliadin content lower than commercial semolina. Finally, the fate of gluten proteins was evaluated upon in-vitro simulated gastroduodenal digestion experiments carried out on raw wheat flours. The in-silico toxicity evaluation assessed a significantly lower number of toxic epitopes than commercial semolina. Conclusions The integrated approach confirmed that durum wheat breeding programs accomplished in the last decades improved the gluten strength, without causing an increment of toxic epitopes. Even if none of the selected genotypes can be considered safe for CD patients, a lower toxicity level could be envisaged and, in perspective, they may represent an innovative solution in genetically predisposed individuals who may develop CD after prolonged gluten consumption.