Producing safe food is non-negotiable. This is particularly true for gluten-free foods intended for the approximately 3.2 million Americans with celiac disease, for whom trace amounts of gluten can cause debilitating health problems. 

For food manufacturers, ensuring that a product is gluten-free (GF) requires careful attention to the ingredients used to make the food, as well as the manufacturing environment in which it is made. As with any critical process, science and best practices play an important role in advancing knowledge about safe GF food manufacturing that will ultimately lead to successful results. 

Process best practices

Understanding a supplier's processes is extremely important when determining if they can be a trusted source of gluten-free raw materials. The materials that present the greatest source of potential gluten contamination are other non-gluten grains, so these suppliers should be the subject of particular scrutiny. 

In the case of whole or milled grain suppliers (flours, flour blends, rolled, flaked, or extruded grains), determine if their facility is dedicated to gluten-free grains. Or, if they process both gluten-containing and gluten-free grains, are there sufficient controls in place to ensure a consistently gluten-free product?

It is essential to check whether storage areas for incoming material, cleaning equipment, milling/processing equipment and final packaging/totes are separate for gluten-containing and gluten-free grains. Additionally, the processor needs to demonstrate that they have effective cleaning processes in place for anything that is shared. The grain processing operation should also be able to provide records that show the effectiveness of their methods, typically through testing data. 

A best practice is to operate a thorough supplier approval program, conducting on-site audits or off-site document reviews of the supplier's Current Good Manufacturing Practices (CGMP), preventive controls, grower contracts, Allergen and Gluten Control programs, certificates of analysis (COA), and other relevant information before raw materials are ever purchased.

In the case of oats, one option for suppliers is to operate under the definition of what is called a "Purity Protocol”(1). This is a farm-to-plate method of ensuring that oats are gluten-free and have met requirements for seed stock purity as well as criteria for field preparation, planting, harvesting, transport, storage and processing. It also contains methods and standards that could be used for growing any gluten-free grain.

Regardless of the method used to ensure gluten-free grains, our organization published a sampling protocol for detecting gluten-grain contamination in other whole grains, such as oat groats, using visual examination (2). Visual examination is a method that  is more accurate than antibody-based testing for determining the extent of gluten-grain contamination in whole grains because it takes into account the level of sampling needed to detect a rare event, such as a single gluten-grain in a kilogram or more of other product.

Similar precautions may be warranted for other ingredients that are deemed higher risk. For example, several years ago, we surveyed gluten levels in retail single-ingredient spices. Twenty-five samples of eight common spices (cumin, coriander, cloves, fenugreek, sage, thyme, white pepper and mace) from multiple suppliers were examined. Of the samples, 32% had gluten levels that were confirmed by a second test method. While the reason for this contamination was unknown, we began recommending that all manufacturers of gluten-free foods conduct testing of spices whenever they change their supplier or when their supplier changes its sources.

All gluten-free production needs to begin with gluten-free ingredients, and the ingredient procurement and production processes should all be designed with the goal of producing truly gluten-free products, not simply products that meet a regulatory threshold. The U.S. FDA does not accept "dilution" of a contaminated ingredient into a finished product, even if that finished product meets the FDA threshold of 20 ppm. While the market for gluten-free foods is broad, it is essential to remember that a gluten-free diet is a medical necessity for 1% of the population, and the target should always be products that are entirely free of gluten.

Ensure quality with verified testing 

Even if a supplier has a testing program in place, manufacturers should develop their own gluten testing program, not just for finished products, but also for instances such as vetting new suppliers. A key component in ensuring the safety of gluten-free ingredients and foods is the ongoing verification of testing staff competency. 

Internal procedures should require manufacturers to evaluate the competency of their testing staff annually. One way to do this is by providing the testing staff with unknowns – samples where management knows the sample ingredients, but the testing staff does not – to determine if they get the right results. If they do not, the manufacturer will need to figure out why. It might be that the test kit has expired or wasn't used correctly. Verifying testing performance in this way is essential to avoid the possibility of inaccurate test results.

Support with certifiable procedures

While food manufacturers have the option of setting up purely internal procedures to evaluate gluten-free suppliers, accomplishing this can be a complicated task, particularly with suppliers that do not exclusively process gluten-free products. 

For those suppliers, making safe gluten-free raw materials may involve implementing safeguards such as segregated production lines and areas for receiving and storing ingredients, developing procedures for proper handling and labeling of ingredients, sequencing gluten-containing and gluten-free production, determining engineering parameters for air handling systems, equipment and controls, and determining appropriate sanitation procedures, among other considerations. Manufacturers may not feel that they have the expertise to evaluate these processes for each of their suppliers properly.

Looking for suppliers whose products are certified through a third-party gluten-free certification program holds several potential benefits for a food manufacturer. It reduces the risk of improperly designating a raw material as gluten-free and gives the manufacturer the support they need to choose appropriate suppliers. Audits conducted by certification inspectors also verify that the supplier is guided by and meeting high standards in producing their product.

Meeting consumer trust in the marketplace

It stands to reason that a food product is only as good as the ingredients used to make it. Consumers with celiac disease or non-celiac gluten sensitivity (NCGS) rely on clear, accurate information when it comes to the food products they consume. Meeting consumers at the shelf is where transparency in food labeling becomes critical. Manufacturers that are clear in their labeling give consumers confidence that the products they are purchasing meet applicable gluten-free standards. The best way for manufacturers to provide the gluten-free products that consumers can trust is to develop a best practices strategy for approving raw materials that includes supplier review, testing and the potential use of certified gluten-free ingredients.

Source References: 

1.    Cereal Chem. 94(3):377-379
2.    JAOAC 101(1):36-44

Laura K. Allred is the regulatory manager for the nonprofit Gluten Intolerance Group (GIG) and its Gluten-Free Certification Organization (GFCO). Allred’s experience includes a background in immunology and eight years of directing a food testing laboratory and test kit manufacturing operation. The GFCO certification logo is the symbol of trust for the gluten-free community, with more than 60,000 products certified worldwide. 

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