In exciting news from the world of gluten science, the CSIRO have developed a breakthrough method to detect the gluten from rye in food for the first time. However, what is the importance of being able to identify rye, and how might it offer improvements to gluten-free food? Read on to find out more.
As we have previously reported, gluten-free labelled foods in Australian & New Zealand supermarkets must follow strict regulations, limiting the amount of detectable gluten to less than 3mg/kg, while countries such as the US and UK follow a more lenient 20mg/kg. Manufacturers are also required by Food Standards Australia New Zealand (FSANZ) to test for any detectable gluten in their products to ensure compliance.
However, a 2015 US study into the accuracy of GF claims on food labels found that while 90-95% of products tested contained less than 20mg/kg of gluten, the remainder contained more than the allowable amount despite being labelled as gluten-free. Similarly, a Melbourne study found that 9% of food businesses assessed were selling GF-labelled products containing more than the allowable threshold. Various commercially-available assays are utilized by food manufacturers to test for gluten contamination, but drawbacks such as the potential for inaccuracy of results, and inability to identify the specific grains contributing to contamination make it difficult for manufacturers to label their foods correctly.
So far, alternative methods have been clinically shown to be successful in identifying gluten from barley, wheat and oats, however a lack of available data on the peptide sequence specific to rye has halted production of something similar to complete the picture, until now.
Scientists at the CSIRO recently undertook research into developing a technique capable of identifying rye’s specific class of gluten peptides, secalins, in food. A technique called LC-MS/MS (Liquid chromatography–mass spectrometry) was used to analyse 20 variants of rye from Australia and abroad, within which 6 gluten proteins that are common between each of the rye varieties were identified for the first time.
Various supermarket snacks, breakfast cereals, and flours were then tested using this new data. In the foods that labelled rye as an ingredient, the 6 newly identified proteins were found as expected. Concerningly, one breakfast cereal labelled gluten-free was found to contain traces of rye, and a sample of spelt flour contained around 2% rye contaminant.
Although spelt and rye are both unsafe for consumption if gluten-sensitive, the study noted that “this detection highlights the commonality of agricultural comingling”, and accompanies the findings from the Melbourne study mentioned above in emphasizing the ongoing challenges of following a strict gluten-free diet when contamination is often out of the consumers’ hands.
It is hoped that with this breakthrough by the CSIRO, more accurate and specific gluten-detection methods will become available to food manufacturers, ensuring better quality control and safety of their products. In doing so, the gluten-sensitive community would benefit from being able to better trust the gluten-free claims on food packaging without fear of possible contamination from rye and other grains.
Until such testing developments are commercially available, we recommend taking GluteGuard before any meal where food preparation is out of your control. GluteGuard’s patented enzyme action helps to reduce the occurrence of symptoms triggered by hidden gluten in food for those diagnosed with gluten sensitivities.
 Halmos, E.P., Di Bella, C.A., Webster, R., Deng, M., & Tye-Din, J.A. (2018). Gluten in “gluten-free” food from food outlets in Melbourne: a cross-sectional study. Medical Journal Australia, 209(1), pp. 42-43. doi: 10.5694/mja17.00883
 Pasquali, D., Blundell, M., Howitt, C.A., & Colgrave, M.L. (2019). Catcher of the Rye: Detection of Rye, a Gluten-Containing Grain, by LC-MS/MS. Journal of Proteome Research. doi: 10.1021/acs.jproteome.9b00314
 Thompson, T., & Simpson, S. (2015). A comparison of gluten-free foods sold in the United States. European Journal of Clinical Nutrition, 69, pp. 143-146. doi: 10.1038/ejcn.2014.211
 Tyers, P. (2019). Catcher of the Rye: Science can now detect any gluten in any food [News Release]. CSIRO. 15th August. Available at: https://www.csiro.au/en/News/News-releases/2019/Catcher-of-the-rye
Author: Cassandra, Glutagen