Gluten contamination in oat products and products naturally free from gluten

Some countries now allow celiac patients to include oats in their gluten-free diet. Studies have shown that commercially available oats can be contaminated with gluten. The aim of the study was to analyse oat products and products naturally free from gluten to determine the degree of contamination. A total of 88 oat products and 22 products based on maize, rice, millet or buckwheat were analysed, using a commercially available enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody to gliadin. The ELISA is quantitative with a detection limit of 20 mg/kg gluten. Some of the positive samples were also analysed for the presence of DNA from wheat, barley or rye. Thirteen percent of the oat products had gluten content over 200 mg/kg. Of the products naturally free from gluten 14% had a gluten content over 200 mg/kg. There was a tendency for higher levels of contamination with increased processing. The risk of gluten contamination in oat products as well as in non-gluten cereals must be considered. The level of contamination was in most cases low. The results regarding oats can be compared to those of such cereals as maize, rice, buckwheat and millet.