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From: Food Quality & Safety magazine, December/January 2009

Protect Your Customers From Gluten

Manufacturers and regulators respond by developing additional processing parameters

by Giri Veeramuthu, PhD

A Google search of the word combination “gluten free” returns a staggering 7 million results. Many provide information regarding gluten-free ingredients, recipes, and prepared foods currently available in the marketplace. This tidal wave of information is the result of the heightened interest in gluten-free diets of an increasing number of people who have been diagnosed with celiac disease (CD).

People affected by CD, a genetic disorder, are predisposed to an autoimmune response that causes damage to the small intestine when they eat foods containing gluten protein. This damage, in turn, causes the small intestine to lose its ability to absorb the nutrients found in food, leading to malnutrition and a variety of other complications. The disease is diagnosed in Australia, Europe, and the United States. The increasing regularity of this diagnosis has forced food manufacturers and regulatory bodies to develop additional processing parameters and methods of educating consumers. The Food and Drug Administration (FDA) recently proposed a gluten-free labeling rule for voluntary use in foods.1

The term gluten-free is actually deceiving: Not all gluten-containing ingredients cause detrimental effects for those with CD. According to the FDA, grains of wheat (including durum wheat, spelt wheat, and kamut), rye, barley, or triticale (a cross between wheat and rye) are prohibited. The effects of oats are undetermined. Complicating matters are similar peptide molecules found in amaranth, buckwheat, corn, Indian ricegrass, Job’s tears, millet, quinoa, ragi, rice, sorghum, teff, and wild rice, all of which are generally well tolerated by those with CD.

Manufacturers who process wheat or other gluten-containing products increase the risk of falling short of regulatory technical needs. Fortunately, systems such as segregation and proper sanitation can ensure that requirements are met. Given the cost of implementing such systems, however, it is understandable that manufacturers might need to charge a premium to maintain a gluten-free status.

Manufacturing Criteria

Gluten-free diets help to minimize CD, but stringent proposed rules for food manufacturers are problematic. Many requirements need further clarification. Over time, strict avoidance of diets containing gluten can resolve symptoms, reduce associated health risks, and possibly even reverse the damage caused by CD.2

This information leads to conjecture that CD may not be caused by an acute reaction to products containing gluten. Studies have shown that while uncontrolled diets containing gluten trigger harmful effects, ingestion of up to 10 grams of gluten (5 grams of gliadin) a day for several weeks is required for adult gluten challenge studies.3 In other words, adequate quantities over a prolonged period are required to provoke a CD response. If this is true, why do manufacturers need to maintain strict parts per million (PPM) levels in order to achieve gluten-free status? The current standard for claiming gluten-free status is no more than 20 PPM. This stringent standard makes sense in the case of allergens, in which even low PPM levels might cause anaphylactic shock.

Companies can achieve gluten-free status by following certain internal procedures. As industry and regulatory bodies finalize standards, additional external criteria will likely evolve. Methods that manufacturers may use to ensure gluten-free products include dedicated lines or even—depending on the volume of gluten-free products they manufacture—fully gluten-free plants.

Manufacturing facilities could be classified into one of the following categories. A facility processing only gluten-free products could be rated “low risk.” A facility with segregated lines—or proper sanitation controls and validations—with proper processing controls could be rated “medium risk.” A facility with many different allergens, fewer controls, and improper documentation could be given a “high risk” rating.

Manufacturers of gluten-free products in facilities that are not 100% gluten free must have segregated areas for receiving raw ingredients from suppliers. These areas must be placarded and kept free of prohibited substances. Plastic sleeves on pallets and color coding may help plant personnel avoid errors in pulling product or lot tracking for identification. Prior to processing lot numbers, product types and quantities pulled must be documented and verified by a supervisor. This step prevents accidental addition or contamination.

When it comes to processing, equipment must be tested for gluten-free status if it is used to process products containing gluten or other prohibited substances or allergens. Engineering parameters such as air handling systems, enclosed systems or equipment, one-way traffic, and water and pressure controls need to meet specific standards. These safeguards will prevent other areas of production from intermingling with the gluten-free environment.

Because most of these requirements mimic other special situations such as the handling of allergens and organic products, manufacturers with this kind of experience can easily adapt to the changes. Separate lines, equipment, and processes may not be feasible for all manufacturers, but strict adherence to policies and internal guidelines can allow medium- and high-risk manufacturers to provide gluten-free products.

Sanitation Criteria

Manufacturers can perform cleaning procedures specific to products containing gluten. The first step is to validate the sanitation program. A good sanitation program will take into account types of gluten-containing products in order to identify hard-to-clean areas. Three consecutive cleanings should yield fewer than 20 PPM of gluten on hard-to-clean surfaces. Because each type of gluten grain is unique, this program needs to be revisited for cleaning different glutens. Even though all proteins of interest belong to the same family of prolamins and glutenins, there may be subtle differences in sanitation needs.

A sanitarian must ensure that the detergents, strengths of detergents, types of sanitizer, and water temperature are adequate. Sanitation basics teach that acid or alkaline detergents denature proteins easily. Medium- and high-risk facilities may still be able to meet standards if they adopt and validate sanitation recommendations.

Supplier Criteria

Manufacturers should ensure that suppliers provide documentation showing that incoming raw materials are gluten free. A letter of guarantee and a supplier audit can reveal gaps. Manufacturers should ask the following questions:

  • Are proper segregation procedures followed?
  • Do all the manufacturing locations have strict guidelines for meeting the standards?
  • Do suppliers have gluten-free dedicated lines?
  • Do suppliers handle any prohibited grains?
  • Do the distributors follow segregation policies?

In addition, ask your suppliers to go through a third-party certification process to certify gluten-free status. Certification agencies such as Gluten-Free Certification maintain lists of manufacturers, suppliers, and products that they have certified as gluten free.

Testing for gluten-free status is quick and uses the enzyme-linked immunosorbent assay (ELISA) principle. Various companies, including Neogen Corporation, ELISA Technologies, R-Biopharm Group, and Tepnel Biosystems manufacture such kits in the United States. The kits are simple to use and will satisfy regulatory needs; most are Association of Analytical Communities-approved or in final action. The testing can help to validate and verify raw materials (prior to approving a vendor), equipment (routine clean downs) or finished product (to declare gluten-free status). The sampling matrix can be varied based on need and priority.

From a quality assurance perspective, such sampling needs to represent the entire spectrum in question. Samples should be taken from a large pool of raw and finished product, and a composite sample product can be tested. Compositing can vary depending on the client requirement and the product in question. For a pre-operational purpose, multiple sample sites of hard-to-clean parts of a piece of equipment can be used to measure its gluten-free status. Hard-to-clean areas must be identified based on historic knowledge gleaned from previous micro or adenosine triphosphate bioluminescent tests.

The test result interpretation is simple, irrespective of the product or equipment analyzed or the kits used for the studies. A negative result indicates only controls appearing during visual examination, while a darker color in the test well indicates the detection of more than 20 PPM of gluten. Keep in mind that manufacturers have their own, additional testing requirements and conditions.

Interestingly, low-protein wheat flour and wheat starch claiming to be gluten free are available commercially. With the new ruling, manufacturers need to ensure that their products contain no more than 20 PPM gluten. Detecting amounts beyond these limits could lead to a misbranded product. The reasoning for a 20 PPM limitation is still too stringent, however, and may be the result of the availability of better technologies than are required for practical purposes. Time and further studies will reveal whether or not this is the case.

Future Uncertainties?

CD is diagnosed when an individual affected by its symptoms consumes a diet that contains gluten over a period of time. No literature or studies have found proof that the disease manifests in patients who consume diets containing low PPM levels. It is possible that the FDA, as a regulatory agency, would err on the side of excess caution in adhering to the 20 PPM standard. The food industry has experienced this response in other instances, such as when hazard analysis and critical control point regulations called for a zero fecal tolerance limit. This was a significant requirement for meat packers. Slaughterhouses were forced to perform correctly in a very short span of time, and many could not comply. But, over time, the outcome of new regulations has generally been beneficial, as well as an eye opener for consumers and the food industry. Few companies were shut down due to management’s inability to comply with the zero fecal contamination regulation.

Gluten-free standards must be developed with prudence and practicality to ensure, first and foremost, that consumers are protected but also that requirements are prudent. The potential benefits from a gluten-free requirement are fewer product recalls, less brand degeneration, and fewer lost customers.

As knowledge about CD increases, the market for gluten-free products will increase. Consumers already pay a premium for these products, making them a very attractive offering. Even mainstream retailers are dedicating separate shelves for special needs, targeting those who are looking for gluten-free products.

In the near term, regulatory bodies should work for better requirement definitions, and industry groups should come to a consensus on proposed definitions. This increase in structure will force manufacturers to adhere to the same standards and define their plants’ risk levels on an even basis. Such demarcation will help retailers to choose high quality vendors and will provide consumers with a better understanding of the products they are considering for purchase, so that they can decide whether they are willing to pay the premium.

The demand for food technologists who specialize in developing new gluten-free products will increase. These specialists will need to come up with innovative products without jeopardizing taste and product aesthetics.

Patty Stewart is the president of Whole Bakers, which manufactures a line of high quality gluten-free cookies. After being diagnosed with CD, Stewart founded the company when she discovered the need for great tasting gluten-free foods. “People with CD have to be extremely careful about what they buy for meals, what they purchase at grocery stores, what they eat at restaurants, etc.,” she says. Few of the supposedly gluten-free products that are currently on the market maintain certificates of gluten-free manufacturing that assure no reactions, Stewart explains. “Checking labels for gluten free is important, but checking labels for ‘certified gluten free’ is even more important,” she says. “In order to stay well, people with CD must avoid gluten for the rest of their lives.”

As an industry, we have an obligation to help people with CD know for sure they are doing just that.

Dr. Veeramuthu is vice president of quality assurance at PacMoore Products, Inc. He can be reached at (219) 932-2666 or


  1. United States Food and Drug Administration. Food labeling; gluten-free labeling of foods. Proposed rule. Federal Register Vol. 72, No. 14. Washington, DC: US Dept of Health and Human Services; 2007. Available at: Accessed December 9, 2008.
  2. Pietrzak MM, Catassi C, Drago S, et al. Celiac disease: going against the grains. Nutr Clin Pract. 2001;16(6):335-344.
  3. Ciclitira P. Guidelines for the management of patients with coeliac disease. Gut. 1996; 39(Suppl 2):I-V.



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