A polymerase chain reaction directed to detect wheat glutenin: Implications for gluten-free labelling

Abstract

Gluten enteropathy or celiac disease (CD) is treated by strict adherence to gluten-free diet for life. Trace amounts of wheat in food from farm to table manifests as a major risk to these individuals. A qualitative polymerase chain reaction method was developed by selectively amplifying a 135 bp fragment of the glutenin gene to detect wheat DNA in a plethora of raw and heat processed foods. The limit of detection was 21.5 pg of DNA. The absence of amplification in other cereals such as oat, rye, barley and maize renders this method exclusive for detection of wheat. The detection of wheat DNA in thermally processed foods by this method, despite extensive DNA fragmentation, evinces the suitability and applicability of the method for labeling gluten-free foods. This method complements the immunochemical methods toward addressing food safety in CD patients and wheat allergics.