COMPANIES manufacturing “gluten-free” foods need to test their products more frequently, after multiple samples were found to contain more than the national standard of no detectable gluten, according to research published online by the Medical Journal of Australia.
Dr Jason Tye-Din, head of coeliac research at the Walter and Eliza Hall Institute of Medical Research in Melbourne, and a gastroenterology consultant at the Royal Melbourne Hospital led a team that tested 256 of the most commonly purchased manufactured foods labelled as “gluten-free” in Australia. Foods were homogenised on the day of purchase and analysed at the National Measurement Institute in Melbourne using the RIDASCREEN R5 gliadin kit (R-Biopharm). Positive samples were re-tested with the AgraQuant G12 gluten kit (Romer Labs) for confirmation.
“If gluten was detected in a sample, a fresh sample of the food was purchased and analysed,” Tye-Din and colleagues wrote. “The manufacturers of products containing detectable gluten were notified.”
“Seven samples (2.7%) from six manufacturers contained detectable gluten at levels of up to 49 parts per million (ppm). Two of these samples were from the same manufacturer and contained the same two ingredients (not named to protect identity of the manufacturer). One of the seven items had already been recalled by its manufacturer; follow-up batches of five of the other six items also contained quantifiable levels of gluten (5–21 ppm),” they found.
“We found that 2.7% of foods labelled ‘gluten-free’ were not compliant with the national standard of no detectable gluten; two contained gluten at levels exceeding the less strict Codex Alimentarius CODEX (Europe) and Food and Drug Administration (United States) thresholds for “gluten-free” labelling (20 ppm).”
The authors said that although the levels of detected gluten were generally low, a gluten-free pasta contained over 3 mg of gluten in a standard single serve and this level “could be harmful, especially if consumed frequently”.
“Repeat batches of five of seven contaminated foods also contained gluten, indicating that the initial results did not reflect isolated episodes of contamination,” Tye-Din and colleagues wrote. “As three of the seven items were produced in dedicated gluten-free factories, gluten contamination of ingredients supplied by outside sources should be examined.”
The authors concluded that “more frequent gluten testing, feasible for many companies, would reduce the risk for people with coeliac disease”.
- Cate Swannell