Gluten residues in gluten-free foods sold in Christchurch, New Zealand: Comparison of LC-MS and ELISA methods

Abstract

Two distinct immunologically-mediated diseases, Coeliac disease and wheat allergy, are associated with ingestion of proteins from wheat and some related cereals. Both conditions are usually managed by adherence to a gluten-free (GF) diet. Two methods for detecting gluten protein were compared: enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-mass spectrometry (LC-MS). The methods were compared for their specificity in analysis of a range of cereals and pseudocereals (buckwheat, quinoa) and the ability to detect gluten in foods claimed to be GF. The ELISA method detected gluten in 6/61 (9.8%) samples, with results in the range of 11-450 mg/kg. LC-MS detected gluten in five of these samples with results in the range of 6-130 mg/kg. These foods have the potential to cause adverse health effects in individuals with Coeliac disease or wheat allergy.