Mechanically Separated Oats

What oats...

Through Yonder Package Breaks?

This article was originally published in our November 2015 newsletter. Due to the importance of pure oats, I decided to beef it up a bit and post it here. Thanks!

Alan Klapperch
Branch Manager

updated 10/25/22 - Added GFWD’s Purity Protocol link as it back online.
updated 10/14/22 - Add Gluten-Free Watchdog’s Special Statement on Purity Protocol Oats
updated 10/14/22 - Removed Gluten-Free Watchdog’s Oats link. They’ve removed the link temporarily.
updated 10/30/19 - Updated Purity Protocol Oats list from GFWD
updated 04/30/19 - Add GIG and GFWD links
updated 12/31/18 - Updated GFW’s purity protocol oats list.
updated 04/20/17 - Add Healio article "Oats appear safe for patients with celiac disease" .
updated 04/11/17 - Add GIG's Purity Protocol definition.
updated 03/02/17 - Added Trader Joes GF Rolled Oats to Purity Protocol Heros
updated 01/25/17 - Added Gluten-Free Watchdog's Updated Position Statement on Oats
updated 01/05/17 - Add more Gluten-Free Watchdog links
updated 10/28/16 - Added video and Dietitians in Gluten Intolerance Diseases (DIGID) Oats handout
updated 06/08/16 - Added Bakery on Main to Purity Protocol Rebels
updated 05/18/16 - Added GFW oat product analysis.

Oats and products made with oats have been burning up the internet lately. People in the gluten-free community started asking manufacturers exactly what kind of oats are used in their products…with surprising results.

More on that later, but first a little background information on said ingredient of discussion.

Oats have been controversial for over 20 years. Are they acceptable on a GF diet or not?

The Scoop on Oats

Please use these excellent articles to help you and your medical professionals to make an educated decision if oats are right for you.

Oats appear safe for patients with celiac disease by Adam Leitenberger April 20,2017
Pinto-Sánchez MI, et al. Gastroenterol. 2017;doi:10.1053/j.gastro.2017.04.009.

"Adding oats to increase the nutritional value of a gluten-free diet does not appear to affect symptoms, histology, immunity or serologic features of patients with celiac disease, according to new research published in Gastroenterology."

"These results are “reassuring, and suggest that non-contaminated oats are tolerated by the great majority of patients,” Peter H. R. Green, MD, professor of medicine at Columbia University Medical Center, and director of the Celiac Disease Center at Columbia University, and colleagues wrote. However, they noted that their “confidence is limited by the low quality and limited geographic distribution of the data.”"

To better address the controversies surrounding the safety of adding oats to a gluten-free diet, Green and colleagues reviewed studies evaluating the safety of oats as part of a gluten-free diet in patients diagnosed with celiac disease or the related skin condition dermatitis herpetiformis. They ultimately included 28 studies published up to January 2017 in their analysis, six of which were randomized controlled trials that used pure uncontaminated oats, and two of which were non-randomized controlled trials (RCTs, n = 661), while the rest were observational studies. Only RCT data were included in a meta-analysis.

One year of eating oats showed no significant effects on symptoms, histologic findings, intraepithelial lymphocyte counts, or serologic test results. These findings were comparable in both adults and children.

Further, the results of three non-RCTs suggested that dermatitis herpetiformis lesions did not worsen after consumption of oats. No studies compared regular vs. pure oats.

The investigators noted that all available RCTs were conducted in Europe, and because the purity of oats depends on the country of origin and its regulations, there is an “urgent need for studies in North America and other regions of the world where [celiac disease] is prevalent. Results from studies in Europe using locally sourced oats cannot be extrapolated to North America.”

They concluded that available data suggest celiac patients can safely consume non-contaminated oats, but more rigorous data are needed

Read more: April 20,2017

Be sure to read the entire comment from Dr. DiMarino, Jr.,MD at the end of article.

"Prolamines are the alcohol-soluble portion of the protein in wheat, rye and barley, and are antigenic in celiac patients. The prolamines in oats are not antigenic, so theoretically it’s possible that eating oats should not be harmful to celiac patients. However, some prior studies have suggested that celiac patients may experience a reaction to eating oats.

At the Jefferson Celiac Center, we believe the science behind the idea that the prolamine component of oats is safe as compared with the prolamine in wheat, rye and barley. However, we also recognize that cross-contamination of the oat supply is more likely in the U.S. than in Europe. Therefore, we advise newly diagnosed celiac patients who are still symptomatic to avoid oats. Once their anti-tissue transglutaminase or deamidated anti-gliadin antibody levels normalize, and they become asymptomatic, we advise them to cautiously introduce the purest form of oats available as there are several products that avoid cross contamination. If they become symptomatic again after consuming oats, we know that either cross-contamination has occurred, or they may be one of the perhaps 5% to 10% of patients who also may have an intolerance of oats for reasons unrelated to celiac disease."

Anthony J. DiMarino, Jr., MD
William Rorer Professor of Medicine
Chief, Division of Gastroenterology and Hepatology
Thomas Jefferson University Hospital - Oats and the Gluten-Free Diet by Nancy Lapid:

Nancy Lapid’s article contains summaries of all the North American celiac/gluten free organizations and treatment centers recommendations on oat consumption. - Can People Who Can't Have Gluten Eat Oats? by Jane Anderson:

Gluten Intolerance Group - Hot Topic Oats (Last Updated 06/06/18):

Bottom line

Uncontaminated, certified gluten-free oats are considered safe for most people with celiac disease. Consult with your personal healthcare team before introducing oats into the diet. Quantity should be limited to the recommended maximum of ½ cup dry oats per day.

The main issue surrounding oats for those following a gluten-free diet is cross-contamination. In light of the fact that purity protocols are not regulated, and that mechanical sorting can vary from processor to processor, only consume oats which are labeled – and preferably certified – gluten-free.

Special Statement on Purity Protocol Gluten-Free Oats from Gluten Free Watchdog - Sept 28, 2022

"Based on testing commissioned by Gluten Free Watchdog, we do not recommend the use GF Harvest brand oats as a source of purity protocol oats. This product line will not be included in the updated purity protocol listing on Gluten Free Watchdog.

Also based on testing commissioned by Gluten Free Watchdog, we do not recommend the use of Trader Joe’s gluten-free rolled oats. We have been unable to confirm the source of oats used by Trader Joe’s in this product. Based on language included on product packaging as well as information available on the Trader Joe’s website (see photos), consumers have assumed that the oats in this product are purity protocol.

Gluten Free Watchdog has spoken with all known suppliers of purity protocol oats in Canada (packaging reads product of Canada). According to these suppliers, none of them provide oats to Trader Joe’s. Trader Joe’s has been unable to provide us with the source of their oats.

Gluten Free Watchdog has temporarily removed from the website the listing of purity protocol suppliers. If you are a manufacturer and you sell single ingredient purity protocol gluten-free oat products sourced directly from Avena Foods, Montana Gluten Free, or MGM Seed & Grain/Bay State Milling ONLY, please contact us If you are a manufacturer who previously was included in this listing, please reach out again with updated information.

Gluten-Free Watchdog - Updated Position Statement on Oats (1/25/17):

Gluten-Free Watchdog - Special Report: The Use of Oats in Gluten-Free Foods:

Gluten-Free Watchdog - Controversy continues to swirl around oats & their suitability for a gluten-free diet:

Gluten-Free Watchdog - The gluten-free oats situation & why it is such a sticky wicket:

Currently, most medical professionals say pure, gluten-free oats can be tolerated in limited amounts [up to a 1/2 cup per day for adults].

Many in the gluten-free community would beg to differ with that recommendation because they react to gluten-free oats as well. Those in the grain-free/low-carb community offer convincing evidence that supports their lifestyle too.

Regular followup testing is also advised to make sure intestinal damage is not occurring. For those newly diagnosed, it’s suggested to restrict the use of oats for up to one year.

Also be aware that some celiacs react to the protein found in oats [known as avenin] just as they react to the proteins in wheat, barley, rye.

If you know they cause you discomfort, do not eat them.

The experts who recommend oats, all agree that only pure, uncontaminated gluten-free oats be used - no commercial oats allowed.

Why? Cross contamination with gluten [wheat, barley, rye].

Often times oats are grown in rotation with wheat, barley, and rye. Stray plants can be left behind that get harvested with the oats. Harvesting, transporting, and processing of oats can use the same equipment as gluten-containing grains, thus exposing oats to further contamination.

A 2004 study published in The New England Journal of Medicine reveals "regular" oats should not be considered safe for those requiring a gluten-free diet. Four different lots from three different companies found gluten content ranging from less than 3 parts per million to 1807 parts per million. Gluten Contamination of Commercial Oat Products in the United States by Tricia Thompson, MS, RD

Update April 30th, 2019 - Gluten-Free Watchdog, shares more research from PepsiCo (owners of Quaker Oats brand).
Due in large part to data published in the public domain by Quaker, the celiac disease community continues to learn about the nature of gluten grain cross contact in oats, including that:

Grains of wheat, barley, and rye are unevenly distributed within a given amount of oats.

Despite what may be the best efforts of suppliers, gluten-containing grains have been found in both final product purity protocol oats and final product mechanically and optically sorted oats.


Read More: Oats Revisited: Quaker Gluten-Free Oats -

Update January 5th, 2017
- Tricia, founder of Gluten-Free Watchdog, shares another article from PepsiCo (owners of Quaker Oats brand) about testing oats.
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.

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, my 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.

Read More:
Quaker's first article on oat testing:

Update May 18th, 2016 - Mining through five years of testing, Gluten-Free Watchdog finds oat products are at higher risk of gluten contamination compared to gluten-free labeled foods as a whole. 35 products containing oats as first or second ingredient were tested. Analysis shows:

  • 28 of 35 (80%) of oat products tested below 5 parts per million of gluten.
  • 5 of 35 (14%) of oat products contained 20 ppm of gluten or more.
  • 2 or 35 (6%) of oat products contained more than 5 ppm but less than 20 ppm of gluten.

  • Approximately 5% of all gluten-free labeled foods tested at or above 20 ppm of gluten vs 14% of oat products.

Update October 28th, 2016 - Dietitians in Gluten Intolerance Diseases (DIGID) held a breakfast meeting at this year's Food & Nutrition Conference and Expo (FNCE). Topic: Oats.

This event was sponsored by purity protocol oats producer, GF Harvest Oats. GF Harvest Oats owner, Seaton Smith was the keynote speaker. A mechanically & optically sorted oats supplier was also asked to participate, but declined to speak. Tricia Thompson, RD, MS of Gluten-Free Watchdog volunteered to present information about sorted oats.

Tricia was kind enough for create
a video to accompany the DIGID oats meeting handout. Please have the handout open while watching the video.

The presentation includes:
  • Basic definitions.
  • Background information on gluten contamination levels found within commercial oats.
  • Gluten content testing results of oats.
  • Testing protocols of millers of mechanically sorted oats (Quaker, General Mills/Cheerios, Grain Millers, La Crosse Milling).
  • A PepsiCo Inc./Quaker Foods and Snacks (QFS) study on testing oats for gluten content. This important study reveals the difficulties in testing grains for gluten. Bottom line: Final product testing for oats must be extensive!

    For an easy-to-understand write up on this study (and links to actual study), please check out "
    Must Read Study Courtesy of Quaker on Testing Oats for Gluten" by Tricia Thompson, RD

OK - back to the issue at hand…

Shortly after Cheerios announced their
recall of 1.8 million boxes due to gluten contamination, Quaker Oats announced they will now be offering “gluten-free" oat products.

Like General Mills, Quaker Oats will not be using oats grown/harvested/transported using a purity protocol. They are using regular oats that will be "cleaned" via mechanical or optical sorting methods.

What is a Purity Protocol?

On April 7th, 2017, Gluten Intolerance Group of North America and four of the largest Purity Protocol oat producers in North America (Montana Gluten Free Processors LLC, Cream Hill Estates, Ltd., Gluten Free Harvest/Canyon Oats, Avena Foods Limited) published a consensus definition of Purity Protocol oats.

Having a standard definition allows consumers and buyers to know that oat suppliers are following industry-accepted or uniform best practices.

Protocol Requirements.
Purity Protocol oat packagers/processor/millers must ensure that their grower network is adhering to the following farm requirements (as specified in grower agreements):

  • Seed Purity: All gluten-free oats must start from seed, either purchased or harvested from the previous crop, that is free from all gluten-containing grains as determined by seed counts.
  • Crop Rotations: Growers shall follow a nongluten crop rotation, or a minimum three-year crop rotation between the last gluten-containing crop and the first pure oat crop, and document all previous crops grown.
  • Isolation Strips: Isolation strips are required between adjacent gluten-containing crops or conventional oat crops and must be a minimum of 6 feet in width.
  • Field Inspection: There must be inspections for potential sources of gluten cross-contamination during the growing season; these should be performed by third party inspectors trained specifically for gluten-free inspection.
  • Traceability: The farm must identify the oats by land location, and document the harvesting equipment, cleaning equipment, transports, storage facilities, and final distribution for the grain from each location.
  • Equipment Cleaning (trucks, cutters, harvesters, augurs, conveyors): Whenever possible, growers should use dedicated equipment. If not, they must use a validated cleaning process prior to handling gluten-free crops. Growers must also maintain documentation of the previous grains in the equipment.
  • Harvest Samples: These must be visually inspected, preferably by a third party laboratory, for purity. Sometimes referred to as a “seed count.”
  • Storage: Dedicated storage should be maintained for gluten-free oats.
  • Cleaned Samples: Growers must visually inspect samples for gluten-containing grains prior to scheduling deliveries.

Conformance with the grower agreement must be documented either by the grower or through an audit by the purchaser. There must be validation that the grower agreement is in compliance with these requirements through documentation and inspection records. The documentation must be reviewed and verified. Samples must be visually inspected by the purchaser for purity prior to receipt or unloading at the purchaser’s facility.

Purity Protocol oat packagers/processor/millers must also ensure that they meet the following processing requirements:

  • Dedicated gluten-free receiving systems.
  • Dedicated gluten-free in-process tanks/silos/storage.
  • Dedicated gluten-free grain cleaners, or appropriate procedures for cleaning grain-cleaning equipment and for the storage of portable grain cleaners.
  • Dedicated gluten-free milling equipment.
  • Dust control/collection procedures and schedules for changing or cleaning filters.
  • Dedicated pneumatic equipment/aspirators.
  • Dedicated extrusion equipment, or written procedures for cleaning or purging extrusion equipment, if applicable. Must document purge volume, and that purge material tests negative for gluten prior to beginning gluten-free processing.
  • Dedicated baggers/fillers.
  • Dedicated pre- and postprocess containers (such as totes).
  • Dedicated rail cars, trucks, or transports, or procedures for the cleaning and inspection of rail cars, trucks, or transports used to deliver product to other facilities or customers.
  • Sorting equipment may not be used for oats as a substitute for obtaining purity, but may be used as a supplement to the purity protocol to ensure purity.
  • The final product must meet the 20 ppm threshold in order to be labeled gluten-free in the United States, Canada, Europe, and other countries following the Codex Alimentarius guidelines. The product must meet the regulations for gluten-free labeling in the country of sale.
  • The final product must meet the 10 ppm threshold in order to be certified gluten-free by GFCO.

While the requirements of the Purity Protocol are excellent for reducing the risk of gluten contamination from wheat, rye, barley, and their hybrids and related grains, these steps do not remove the requirement that the final product be verified as containing less than 20 ppm gluten in order to be labeled gluten-free, or less than 10 ppm gluten to be certified gluten-free by GFCO.

Definition of the “Purity Protocol” for Producing Gluten-Free Oats
Read more:

Why the fuss over Purity Protocol Oats? Again, it goes back to [the lack of] cross contamination with gluten [wheat, barley, rye].

For years, the gluten-free community have been told to only use pure, certified gluten-free oats due to the gluten contamination risks. In the past, this meant acceptable oats were produced and processed according to a purity protocol similar to the one described above.

Most recently, it's been difficult to determine the pedigree of oats used in a product. Companies do not always give clear answers when asked about the oats in their products. As some of the manufacturer's statements have shown (see below), they are using a combination of purity protocol oats and "cleaned" oats, or straight "cleaned" oats.

For a more detailed look at this aspect, please read Gluten-Free Watchdog's
"Gluten-free oat production: Purity protocol versus mechanical or optical sorting: Does it matter to you?"

Looking for a list of Purity Protocol Oats? Look no further…


Oats produced under a gluten-free purity protocol:
Listing of suppliers and manufacturers

What is Mechanical/Optical Sorting?

Mechanical or optical sorting are methods to remove all unwanted kernels of wheat, barley, and rye from the oats. These processes "clean" regular oats after they've been harvested and transported to the processing facility.

Mechanical sorting methods of grains and seeds have been around since the late 1960s, according to the USDA. These sorters use a variety of physical characteristics like size, shape, density, texture, terminal velocity, electrical conductivity, color, and resilience.

As technology advances, these processes improve (but is it enough?) General Mills spent five years and millions of dollars to build a seven-story tall building to "clean" the oats.

Optical sorting uses high speed, high resolution cameras and proprietary software to detect size, shape, and color parameters. Rejected items are ejected from the system using blasts of precise, high pressure air.

The jury is still out on the effectiveness of these cleaning methods. Will they create a product that is truly gluten-free? Only time and proper extensive testing will tell.

Quaker Oats have also opted for the optical and mechanical sorting methods (aka “proprietary”) of removing gluten grains from their oats. However, Quaker Oats reportedly have instituted better testing protocols than their competitor.

Quaker Oats describes their gluten-free oats processing and testing protocols to Gluten Free Watchdog:

Yes, even a gluten-free certified product may use mechanically separated or optically sorted oats in their products.

Bottom line, we don’t always know what type of oats are used in the product unless we ask the food manufacturer.