Quaker researchers publish a second study highlighting the difficulties associated with testing oats for gluten contamination

Note: This is one of two companion articles published today on oats. An updated position statement on oats from Gluten Free Watchdog will be published in the near future.

PepsiCo scientists recently published a second article in the scientific peer-reviewed literature on the difficulties associated with testing oats for gluten contamination. This article entitled “Kernel-based gluten contamination of gluten-free oatmeal complicates gluten assessment as it causes binary-like test outcomes” compliments their first article entitled, “Gluten-containing grains skew gluten assessment in oats due to sample grind non-homogeneity.”

Bottom Line. Based on the findings of the research by scientists from PepsiCo, Gluten Free Watchdog calls on ALL suppliers and manufacturers of gluten-free oats whether purity protocol or mechanically/optically sorted, and their certifying bodies to reevaluate their testing methodology and requirements for certification, respectively.

Both articles should be read in full by all gluten-free certification organizations, oat suppliers (purity protocol and sorted oats), manufacturers, testing labs, and anyone commenting on the state of oat safety for persons with celiac disease.

The articles may be accessed at http://www.sciencedirect.com/science/article/pii/S0308814616312614 and http://onlinelibrary.wiley.com/doi/10.1111/ijfs.13288/full

Note: The first article is not open access. According to Quaker this is not an option available through the journal. Quaker payed a fee for the second article to be available open access.

A summary of the first article (i.e., Gluten containing grains skew gluten assessment in oats due to sample grind non-homogenity) is available at https://www.glutenfreewatchdog.org/news/must-read-study-courtesy-quaker-testing-oats-gluten/

Key Points. Below are some key points from the second article (i.e., Kernel-based gluten contamination of gluten-free oatmeal complicates gluten assessment as it causes binary-like test outcomes).

• Oats labeled gluten-free and produced by two large, well known US producers were purchased from store shelves in the US in 2014. This represented 965 servings of approximately 45 to 50 grams per serving.
  • Based on a single test per serving (one extraction):
    • 95% of the 965 servings tested below 5 ppm gluten (using the R5 ELISA R7001 assay from R-biopharm)
    • 3.21% tested between 5 ppm and less than 20 ppm gluten
    • 1.76% tested at or above 20 ppm gluten
    • 0.62% tested > 80 ppm gluten
    • 1 out of every 57 servings assessed were not in compliance with the FDA rule for gluten-free labeling
  • Regarding the above findings the researchers write:
    • “It is important to note that the above referenced results were all single test outcomes per serving. Our recent research has shown that when a gluten-containing kernel exists in a serving of oatmeal, a single test result can underestimate overall serving gluten content (Fritz et al., 2017)… In other words, much of the gluten from the contaminant kernel remains concentrated in a few pockets within the serving after grinding, not being well dispersed. So consequently, a small test amount, randomly selected from the serving, is more likely than not to undercount overall gluten.”
    • “So it appears a bimodal-like noncompliance pattern (in terms of ppm) has been revealed in the GF oatmeal marketplace in terms of gluten per serving, where numerous BLQ servings are ‘interrupted’ by occasional noncompliant ones, some being several times the regulatory limit.
  • The researchers go on to assess the implications of kernel-based gluten contamination. Please see the complete manuscript (open access) for details. http://onlinelibrary.wiley.com/doi/10.1111/ijfs.13288/full

Additional information provided by Quaker. “At Quaker, we evaluate 3,000 servings worth in every production run in order to account for the binary type outcome of ppm gluten per serving that kernel based contamination presents. We’ve been able to show both in theory and on store shelves that either a serving is gluten free (containing no gluten kernel) or is well over the 20 ppm threshold when a gluten kernel exists, however, we are unable to share our testing sources with you. The issue for the celiac consumer is that consuming gluten free oats that have not been tested in this manner would result in most servings being fine but then they would consume a kernel contaminated serving which would be several times over the FDA limit.

This realization affects the way we test our gluten free products, because one serving may cause a serious reaction and therefore we needed to find a way to account for this in our testing method. This is true for both sorted and purity protocol oats, where sampling and testing to this scrutiny is necessary in order to avoid any gluten containing kernels from making their way to the final product.”

Recommendation. The situation with oats continues to evolve. As mentioned above, Gluten Free Watchdog’s position statement on oats will be updated in the near future. In the meantime, our advice is:

• Choose your oat products based on your comfort level with regard to the level of information provided to you by manufacturers. You may want to consider the following:
  • Does the manufacturer disclose whether they use purity protocol or sorted oats?
  • Do they disclose their testing protocols?
  • Do they disclose the assay they use to test oats for gluten contamination?
  • If a manufacturer refuses to answer any of these questions or responds by saying the information is proprietary, the advice of Gluten Free Watchdog is to move on to another company.