Gluten cross contact in oats: retrospective database analysis 2011 to 2023.

It is long-established that oats are at substantial risk for cross contact with gluten-containing grain. Specially processed gluten-free oats, whether purity protocol or mechanically/optically sorted, made it possible for this grain to be included in a gluten-free diet in the U.S. Gluten Free Watchdog (GFWD) (Manchester, Massachusetts, United States) has been assessing the gluten content of labeled gluten-free foods since 2011. In 2022, there was an apparent increase in the number of oat products testing with quantifiable gluten at or above 5 mg/kg or parts per million (ppm). The purpose of the present study was to assess the levels of gluten in foods containing oats to determine if there were any trends. In this retrospective database analysis, GFWD product test reports from April 2011 to May 1, 2023 were searched using the term "oat." The search identified 213 individual packages of food that contained the word "oat" in the ingredients list. The test results for these packages of food were reviewed. Of these, 24 (11%) tested with quantifiable gluten greater than or equal to 5 mg/kg (ppm). The percentage of oats testing with quantifiable gluten varied per year but spiked in 2022 at 35%. It is not possible to know for certain what caused this increase. The drought during the oat growing season of 2021 could be a major factor. This drought impacted oat crops in both the US and Canada and led to one of the worst oat crops going back over 150 years. One limitation of this study is that it was a retrospective analysis. Different numbers of oat products were tested each year and these were often different brands of oats and different oat formulations. To assess the level of gluten cross contact in oats going forward a much larger prospective study should be conducted.

Consumer-Led Investigation into Potential Issues That Arise When Testing Dairy Matrixes for Gluten With the NIMA Sensor.

BACKGROUND: Some consumers with celiac disease use personal, point-of-use gluten detection devices to test food. False-positive results may occur due to sampling, matrix effects, and sensor issues. OBJECTIVE: The purpose of the present study was to determine if the positive gluten results some users were obtaining when testing cream cheese and materials of similar consistency were false positives and, if so, what might be causing them to occur. METHODS: Cream cheese, soft cheese, and yogurt were tested for gluten using the Ridascreen Gliadin R7001 sandwich R5 ELISA and the Ridascreen Gliadin R7021 competitive R5 ELISA. Two test portions were taken, extracted, and tested from each homogenized material. Materials were also analyzed for gluten using a NIMA sensor, a personal, point-of-use gluten detection device. Multiple test portion weights were tested beginning at 0.13 to 0.17 g (the ideal weight of the test portion according to the NIMA sensor development team). RESULTS: Using the sandwich R5 ELISA and the competitive R5 ELISA, all materials tested below the lower LOD for gluten. Using a NIMA sensor, as the weight of the test portion tested increased, sensor results went from no gluten found, to gluten found, to no test result. CONCLUSION: The gluten found results using the NIMA sensor are likely false positives that appear to correspond with the weight and volume of the material tested, as well as the viscosity. There is also an apparent disconnect between the gluten found result reported by the sensor and an interpretation of the lateral flow device (LFD) strip result when assessed by eye which should also be taken into account. Ideally, NIMA sensor users should be advised on the weight amount of material to analyze and test portions should be weighed before being used with the NIMA sensor. However, this is not a practical solution when testing in many environments, including restaurants. HIGHLIGHTS: Slight variations in weight and volume of test materials can result in false positive results when testing dairy matrixes for gluten using the Nima sensor.

Lentils and Gluten Cross Contact.

Lentils are naturally gluten-free and are recommended for people with celiac disease and other gluten-related disorders. However, like oats, they appear to be at a heightened risk of cross contact with gluten-containing grains. The purpose of this study was to spot check for the presence of errant gluten-containing grains in a variety of brands of lentils purchased in 2021. Twenty-five bags of different dry lentil products representing 24 brands were purchased online and at various grocery stores. Each bag of lentils was individually hand sorted. Two of the 25 packages of lentils contained errant gluten-containing grains. One 16-ounce (454 g) bag contained a grain of wheat. Another 16-ounce (454 g) bag contained a grain of wheat and a grain of barley. For a product to be considered gluten-free in the United States, it must contain <20 mg of gluten per kilogram (or 20 parts per million of gluten). A product at the 20-ppm level of gluten should contain no more than 2 intact gluten-containing grains per kilogram or 35.27 ounces (1,000 g) of food (or 1 intact gluten-containing grain in 17.64 ounces [500 g] of food). Based on these calculations, a 16-ounce (454 g) bag of lentils containing 1 intact gluten-containing grain would not be considered gluten-free. Lentils are at risk of cross contact with gluten-containing grain. Consumers should continue to sort through lentils removing foreign grain, and rinse sorted lentils under running water to remove grain dust before cooking.

Gluten-Free Foods Cooked in Shared Fryers With Wheat: A Pilot Study Assessing Gluten Cross Contact.

Introduction: Consumers with celiac disease are discouraged from eating fried foods cooked in shared fryers with wheat-containing foods at restaurants based on presumed gluten exposure. The purpose of the present study is to assess gluten levels of fries free of gluten-containing ingredients cooked in shared fryers with wheat. Methods: 20 orders of fries were purchased from 10 different restaurants. Restaurants confirmed that fries and oil were free of gluten-containing ingredients. All restaurants confirmed that their fryers were used to cook wheat-containing foods. Fries were sent to Bia Diagnostics and tested in 1-gram duplicates using the R7001 sandwich R5 ELISA and the R7021 competitive R5 ELISA. A microwave control also was run. Results: The sandwich ELISA found gluten in 9/20 fry orders (7 to > 80 ppm). The competitive ELISA found gluten in 3/20 fry orders (14 to > 270 ppm). In the microwave control (60-ppm gluten mixture of wheat flour and canola oil), the unheated mixture tested at a mean level of 64 ppm gluten using the sandwich ELISA and 137 ppm gluten using the competitive ELISA. The mixture heated to 190°C tested at a mean level of 55 ppm gluten using the sandwich ELISA and < 10 ppm and 16 ppm gluten using the competitive ELISA. Discussion: Based on test results, 25% of fry orders would not be considered gluten-free. Summary: Gluten cross contact may occur when gluten-free foods are cooked in shared fryers with wheat. ELISAs may underperform when analyzing for gluten that has been heated.

Stakeholders' Guidance Document for Consumer Analytical Devices with a Focus on Gluten and Food Allergens.

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.

Nutrition assessment in celiac disease.

The gluten-free diet is currently the only treatment for celiac disease, and patients should be monitored closely by a dietitian who is knowledgeable regarding this diet. Evaluation by a dietitian includes a comprehensive assessment of dietary history, with an emphasis on caloric and micronutrient intake. Patient knowledge of the gluten-free diet is assessed and interpretation of food labels is taught. Identification of micronutrient deficiencies or comorbid gastrointestinal conditions may occur during a comprehensive dietary assessment. In patients with evidence of gluten exposure, a thorough evaluation for cross-contamination is performed.

Gluten contamination of grains, seeds, and flours in the United States: a pilot study.

Under the Food Allergen and Consumer Protection Act, the Food and Drug Administration (FDA) must issue a rule for the voluntary labeling of food as gluten-free. In the proposed rule, many single-ingredient foods, such as millet, are considered inherently free of gluten. Inherently gluten-free grains will be considered misbranded if they carry a gluten-free label and do not also state that all foods of the same type are gluten-free (eg, "all millet is gluten free"). Twenty-two inherently gluten-free grains, seeds, and flours not labeled gluten-free were purchased in June 2009 and sent unopened to a company who specializes in gluten analysis. All samples were homogenized and tested in duplicate using the Ridascreen Gliadin sandwich R5 enzyme-linked immunosorbent assay with cocktail extraction. Thirteen of 22 (59%) samples contained less than the limit of quantification of 5 parts per million (ppm) for gluten. Nine of 22 (41%) samples contained more than the limit of quantification, with mean gluten levels ranging from 8.5 to 2,925.0 ppm. Seven of 22 samples (32%) contained mean gluten levels >/=20 ppm and would not be considered gluten-free under the proposed FDA rule for gluten-free labeling. Gluten contamination of inherently gluten-free grains, seeds, and flours not labeled gluten-free is a legitimate concern. The FDA may want to modify their proposed rule for labeling of food as gluten-free, removing the requirement that gluten-free manufacturers of inherently gluten-free grains, seeds, and flours must state on product labels that all foods of that type are gluten-free.

Commercial assays to assess gluten content of gluten-free foods: why they are not created equal.

A standardized method of analysis is needed to quantitatively determine the gluten content of food and provide the basis for enforcing regulations regarding use of the term gluten-free in food labeling. People with celiac disease should feel confident that foods labeled "gluten-free" have been assessed for gluten using the same "best available" methodology. The Association of Analytical Communities and the Codex Alimentarius Commission endorse different methods. Both are used by manufacturers in the United States to determine the gluten-free status of food. The sandwich omega-gliadin enzyme-linked immunosorbent assay (ELISA) is the official method of the Association of Analytical Communities. It is able to quantify native and heated gluten. It is unable to accurately detect and quantify barley prolamins, can over- or underestimate gluten content, and cannot accurately quantify hydrolyzed gluten. The sandwich R5 ELISA was endorsed by Codex for gluten determination. It is able to quantify native and heated gluten. One criticism is that it overestimates barley hordein. It also is unable to accurately quantify hydrolyzed gluten. Foods that can be reliably assessed for gluten using a validated commercially available ELISA are those contaminated with native and heated proteins from wheat, barley, and rye. The degree of confidence that can be placed in a manufacturer's assertion that a product is gluten-free is based on the assay used to determine the gluten content and the specific food analyzed.

Oats and the gluten-free diet.

Whether oats should be included in a gluten-free diet has been debated for half a century. In 1995, the largest and most scientifically rigorous study on the safety of oats was published. Investigators concluded that the consumption of oats was safe for adults with celiac disease. Since 1995, several additional studies have been published. Without exception, these investigations found no adverse effects associated with the regular consumption of moderate amounts of oats. However, there are concerns among some authorities on celiac disease that even if oats themselves are safe, they nonetheless may be contaminated with wheat, rye, or barley. Unfortunately, the extent to which contamination of commercial oat products occurs is not known. Ideally, if a patient appears likely to use oats, they should be advised to consume only those products tested and found to be free of contamination.