Allred et al. Cereal Chemistry 94(3): 377-379

Several oat processors in the U.S. and Canada operate under what is referred to as a Purity Protocol for the provision of gluten-free oats. This term is derived from a Health Canada position statement which indicated that pure oats, which they defined as oats that are harvested, transported, stored, processed and manufactured under Good Manufacturing Practices (GMPs) to minimize the presence of gluten, can safely be consumed by some persons with celiac disease. While proprietary definitions of the appropriate GMPs have been used in industry for many years, no independent definition of the requirements to make a Purity Protocol claim has been published. This paper provides a consensus definition of the Purity Protocol requirements based on input from the four largest Purity Protocol oat processors in North America. This definition provides transparency to gluten-free consumers and allows for auditing of Purity Protocol claim.


Allred et al, Journal of AOAC International 101 (1): 36-44

Obtaining representative test samples for antibodybased testing is challenging when analyzing whole grains for gluten. When whole grains are ground into flour for testing, confocal microscopy studies have shown that gluten tends to exist as aggregates within the starch background, making single-sample testing inaccurate and complicating the ability to arrive at an accurate average from multiple samples. In addition, whole-grain products present a unique risk to gluten free consumers, in that any contamination is localized to specific servings rather than being distributed across the product lot. This makes parts-per-million values less relevant for whole-grain products. Intact grains, seeds, beans, pulses, and legumes offer an alternative opportunity for gluten detection, in that contaminating gluten-containing grains (GCGs) are visible and identifiable to the trained eye or properly calibrated optical sorting equipment. The purpose of the current study was to determine a Gluten Free Certification Organization threshold level for the maximum number of GCGs within a kilogram of nongluten grains sold as specially processed gluten free product and to determine the feasibility of this threshold by evaluating visual examination data from two major oat processors.


  • Consumer Testing Devices
    • Popping et al, Journal of AOAC International, 101 (1): 185-189.
    • Until recently, analytical tests for food were performed primarily in laboratories, but technical developments now enable consumers to use devices to test their food at home or when dining out. Current consumer devices for food can determine nutritional values, freshness, and, most recently, the presence of food allergens and substances that cause food intolerances. The demand for such products is driven by an increase in the incidence of food allergies, as well as consumer desire for more information about what is in their food. The number and complexity of food matrixes creates an important need for properly validated testing devices with comprehensive user instructions (definitions of technical terms can be found in ISO 5725-1:1994 and the International Vocabulary of Metrology). This is especially important with food allergen determinations that can have life-threatening consequences. Stakeholders—including food regulators, food producers, and food testing kit and equipment manufacturers, as well as representatives from consumer advocacy groups—have worked to outline voluntary guidelines for consumer food allergen- and gluten-testing devices. These guidelines cover areas such as kit validation, user sampling instructions, kit performance, and interpretation of results. The recommendations are based on (1) current known technologies, (2) analytical expertise, and (3) standardized AOAC INTERNATIONAL allergen community guidance and best practices on the analysis of food allergens and gluten. The present guidance document is the first in a series of papers intended to provide general guidelines applicable to consumer devices for all food analytes. Future publications will give specific guidance and validation protocols for devices designed to detect individual allergens and gluten, as statistical analysis and review of any validation data, preferably from an independent third party, are necessary to establish a device’s fitness-for-purpose. Following the recommendations of these guidance documents will help ensure that consumers are equipped with sufficient information to make an informed decision based on an analytical result from a consumer device. However, the present guidance document emphasizes that consumer devices should not be used in isolation to make a determination as to whether a food is safe to eat. As advances are made in science and technology, these recommendations will be reevaluated and revised as appropriate.


  • The Celiac Patient Antibody Response to Conventional a.nd Gluten-Removed Beer
    • Allred et al.: Journal of AOAC International Vol. 100, No. 2, 2017
    • Enzymatic digestion, or hydrolysis, has been proposed for treating gluten-containing foods and beverages to make them safe for persons with celiac disease (CD). There are no validated testing methods that allow the quantitation of all the hydrolyzed or fermented gluten peptides in foods and beverages that might be harmful to CD patients, making it difficult to assess the safety of hydrolyzed products. This study examines an ELISA-based method to determine whether serum antibody binding of residual peptides in a fermented barley-based product is greater among active-CD patients than a normal control group, using commercial beers as a test case. Sera from 31 active-CD patients and 29 nonceliac control subjects were used to assess the binding of proteins from barley, rice, traditional beer, gluten-free beer, and enzymatically treated (gluten-removed) traditional beer. In the ELISA, none of the subjects’ sera bound to proteins in the gluten-free beer. Eleven active-CD patient serum samples demonstrated immunoglobulin A (IgA) or immunoglobulin G (IgG) binding to a barley extract, compared to only one nonceliac control subject. Of the seven active-CD patients who had an IgA binding response to barley, four also responded to traditional beer, and two of these responded to the gluten-removed beer. None of the nonceliac control subjects’ sera bound to all three beer samples. Binding of protein fragments in hydrolyzed or fermented foods and beverages by serum from active-CD patients, but not nonceliac control subjects, may indicate the presence of residual peptides that are celiac-specific.


  • Gluten Contamination in Commercial Spices in the United States
    • Cynthia Kupper, Sara Boswell, Channon Quinn, Laura Allred – Gluten Intolerance Group (GIG)
    • Just how “gluten free” are the spices in your pantry? According to new research from the 2015 the Gluten Intolerance Group of North America (GIG-NA), there’s definitely room for improvement. In 2015, GIG-NA conducted an analysis of gluten levels in eight single-ingredient spices sold at retail.These included cumin, coriander, cloves, fenugreek, sage, thyme, white pepper and mace. Twenty-five total samples from various suppliers were tested for gluten using antibody-based ELISA assays, the currently accepted method for gluten analysis, according to GIG-NA. Stated Laura K. Allred, Ph.D., regulatory and standards manager at GIG-NA, “Of the 25 total samples analyzed, eight (32%) had detectable gluten levels that were replicated by a second test method. Gluten levels were greater than 10 parts per million (ppm), the GFCO threshold, in six (24%) samples. Three (12%) of the samples, representing two different spices, had levels of gluten greater than 20 ppm, the FDA limit for a recall.” Allred cannot be sure of the reason for this contamination, but she said, “it may result from cross contamination in facilities that process both spices and grains, or from intentional adulteration of spices with less expensive fillers.” This is not the first time gluten contamination has been found in spices. The Canadian Food Inspection Agency conducted random testing of single-ingredient spices for gluten as part of the Food Safety Action Plan enhanced surveillance initiative in 2011. In a sample sizes of 268 ground spices, 63 samples (24%) contained detectable levels of gluten (greater than 5 ppm). One sample had a level of gluten high enough to initiate a recall.In light of these findings, Allred says that the Gluten Free Certification Organization (GFCO), a GIG-NA program, “has increased its risk level for all spice ingredients and recommends that all manufacturers of gluten-free foods conduct testing of spices whenever they change their supplier or when their supplier changes their source.”