Molecular characterisation of 36 oat varieties and in vitro assessment of their suitability for coeliacs’ diet

Coeliac disease (CD) is a chronic intolerance to gluten, contained mainly in wheat, rye and barley. The only therapy at present is the lifelong exclusion of gluten from the diet. Whether oats can be considered safe for CD patients has long been debated, and oats have been included among gluten-free ingredients only recently (EU Regulation 41/2009), provided the gluten content does not exceed 20 ppm. The aim of this study was to evaluate the suitability of 36 different oat cultivars for CD patients using biochemical and immunochemical approaches. The cross-reactivity between avenins and gliadins was evaluated by both SDS-PAGE/Immunoblotting and ELISA. The protein pattern of each oat cultivar showed both qualitative and quantitative differences that correlated with different binding affinity for specific anti-gliadin antibodies in immunoblotting. In most oat samples, the content of cross-reactive proteins measured by ELISA was below 20 ppm, but in a few varieties was above 80 ppm. Although the taxonomic and biochemical characteristics of oats allow to conclude that their use could be safe for CD patients, it is essential to select those cultivars having the lowest level of gluten-like proteins.