Gluten contamination in manufactured gluten-free foods in Turkey

Celiac Disease: Risks of Cross-Contamination and Strategies for Gluten Removal in Food Environments

Celiac disease (CD) is the chronic immune-mediated enteropathy of the small bowel, manifesting when exposure to gluten occurs in genetically predisposed individuals. Nowadays, the only treatment considered safe for CD is a gluten-free diet (GFD). However, one of the problems faced by celiac patients is the cross-contamination of gluten-free food when preparing meals, in addition to utensils, surfaces and equipment. This study aimed to evaluate cross-contamination in gluten-free products and strategies for removing gluten from cross-contamination in cooking environments. The selection of papers for this integrative review was carried out by searching different databases. Gluten cross-contamination is a global concern for celiac patients in food environments. Although some practices are positive, such as gluten labeling on processed food in several countries, it is crucial to promote good practices in food services around the world. Only a few studies showed effective results in removing gluten from surfaces and utensils; furthermore, sampling was limited, making it difficult to identify appropriate procedures to reduce cross-contamination. The variation in contamination in different kitchen environments also highlighted that celiac patients must continue paying attention to the methods used to prepare gluten-free food. More research is needed, especially into methods of removing gluten from surfaces and utensils, to ensure food safety for celiac patients in many food environments.

Gluten contamination in labelled gluten-free, naturally gluten-free and meals in food services in low-, middle- and high-income countries: a systematic review and meta-analysis

The gluten-free diet is based on the consumption of foods without gluten, which aims to manage celiac disease. The concern of celiac patients is that these foods should be safe. However, gluten contamination can affect these foods. The objectives of this review and meta-analysis were first, to identify articles that detected gluten contamination in gluten-free foods using validated methods. Second, to quantify the overall prevalence of gluten contamination of naturally gluten-free foods, labelled gluten-free products, and meals prepared in food services. Third, to highlight the influence of the country's income and the period of study on this prevalence. The studies were identified in Scopus, Science Direct, Web of Science, PubMed, and Google Scholar. Forty articles were included according to PRISMA guidelines. The statistical meta-analysis was performed using MedCalc 19 software. The results show that in the gluten-free foods analysed, the overall prevalence of gluten contamination was estimated at 15.12% (95% CI: 9.56%-21.70%), with more than 20 mg/kg of gluten. Naturally gluten-free foods were significantly more contaminated than labelled gluten-free products and than meals in food services (28.32%; 9.52%; 4.66% respectively; p < 0.001). Moreover, it was noticed that oats were the most contaminated food. In addition, the prevalence of gluten contamination has significantly decreased over time. The majority of the studies were carried out in upper-middle-income and high-income countries, while only one study was conducted in lower-middle income countries. Therefore, it is necessary to implement preventive actions to reduce gluten contamination, ensuring safe gluten-free foods for celiac patients, including low-income countries.

Food Safety and Cross-Contamination of Gluten-Free Products: A Narrative Review

A gluten-free diet (GFD) is currently the only effective treatment for celiac disease (CD); an individual’s daily intake of gluten should not exceed 10 mg. However, it is difficult to maintain a strict oral diet for life and at least one-third of patients with CD are exposed to gluten, despite their best efforts at dietary modifications. It has been demonstrated that both natural and certified gluten-free foods can be heavily contaminated with gluten well above the commonly accepted threshold of 20 mg/kg. Moreover, meals from food services such as restaurants, workplaces, and schools remain a significant risk for inadvertent gluten exposure. Other possible sources of gluten are non-certified oat products, numerous composite foods, medications, and cosmetics that unexpectedly contain “hidden” vital gluten, a proteinaceous by-product of wheat starch production. A number of immunochemical assays are commercially available worldwide to detect gluten. Each method has specific features, such as format, sample extraction buffers, extraction time and temperature, characteristics of the antibodies, recognition epitope, and the reference material used for calibration. Due to these differences and a lack of official reference material, the results of gluten quantitation may deviate systematically. In conclusion, incorrect gluten quantitation, improper product labeling, and poor consumer awareness, which results in the inadvertent intake of relatively high amounts of gluten, can be factors that compromise the health of patients with CD.

Gluten-Free Labeling Is Misused Frequently in Foods Marketed in Northwestern Mexico

Background: Patients with celiac disease (CD) require a gluten-free (GF) diet, including industrialized products containing ≤ 20 mg gluten/kg. The market status of GF food products is almost unknown in Mexico. Therefore, we studied the GF-labeled products on the northwestern Mexican market and analyzed their gluten content. Methods: We searched for GF type of foods in three different supermarkets of each chain in Mexicali Baja California and Hermosillo Sonora and corroborated the price, origin, and GF certification of each item using internet sites. We quantified the gluten in the foods using the sandwich R5-enzyme-linked immunosorbent assay (ELISA) and detected their immune-reactivity for IgA from patients with CD. Results: The study included >263 different GF-labeled foodstuffs, and 55% of them were made in Mexico. The Mexican items were principally flours, sausages, bread and bakery, milk-type products, and tortillas, while pasta, snacks, and breakfast cereals were mainly imported. The cost ratio of GF products to the conventional mean was 3.5, ranging principally from 1 to 13. The most common GF-labeled foods were flours and pasta (34), cookies and snacks (32), breakfast cereals, sausages, and milk-type products (18-20). Although 36% of the products were certified, 17.4% of the analyzed samples contained >20 mg gluten/kg, mainly the non-certified ones and those made in Mexico. IgA from patients with CD reacted in vitro against gluten proteins from the contaminated GF-labeled products. Conclusion: The accessibility of GF products in the northwestern Mexican market is wide; however, such products are expensive, and some could be risky for patients with CD because they contain gluten, which is recognized by the immune systems of these patients.

Gluten content in labeled and unlabeled gluten-free food products used by patients with celiac disease

OBJECTIVE

Gluten-free (GF) diet is the only reliable treatment for patients with celiac disease (CeD), but data on the extent of gluten contamination in GF food available in India is scanty. We evaluated gluten content in labeled, imported, and non-labeled GF food products currently available in the Indian market.

METHODS

Overall, 794 processed and commercially available packaged GF products (labeled GF (n = 360), imported GF (n = 80), and non-labeled/naturally GF (n = 354)) were collected from supermarkets of National Capital Region of India. Those unavailable in stores were purchased from e-commerce sites or directly from the manufacturers. Gluten level in them was determined by Ridascreen Gliadin sandwich R5 enzyme-linked immunosorbent assay (R-Biopharm AG, Germany). As per Codex Alimentarius and Food Safety and Standard Authority of India, "gluten free" labeled products must not contain > 20 mg/kg of gluten.

RESULTS

Overall, 10.1% of 794 GF products including 38 (10.8%) of 360 labeled and 42 (11.8%) of 354 non-labeled/naturally GF food products had gluten content > 20 mg/kg (range: 24.43-355 and 23.2-463.8 mg/kg, respectively). None of the imported GF products had gluten more than the recommended limits. Contaminated products most commonly belonged to cereal and their products (flours, coarse grains, pasta/macaroni, snack foods) pulse flours, spices, and bakery items.

CONCLUSIONS

A substantial proportion (10.1%) of GF food products (both labeled and non-labeled) available in India have gluten content greater than the prescribed limits of <20 mg/kg. Physicians, dietitians, support group, and patients with CeD should be made aware of this fact and regulatory bodies should ensure quality assurance.

Development of a simple and reliable high-performance liquid chromatography-tandem mass spectrometry approach to simultaneously detect grains specified in food allergen labeling regulation on processed food commodities

An analytical approach using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to simultaneously detect Fagopyrum esculentum Moench (buckwheat) and cereals containing gluten (Triticum species including wheat and spelt, rye, barley, and oats) that were specified in regulations for food allergen labeling on processed foods. Trypsin-digested peptides were purified from different processed food commodities and heptapeptides derived from buckwheat 13S globulin (GFIVQAR, m/z 395.8 [precursor] > 177.0 [product]) and Triticum low molecular weight glutenin (QIPEQSR, m/z 429.3 [precursor] > 616.2 [product]) were specifically detected each species at levels as low as 0.050-0.056 µg/L and 0.028-0.032 µg/L, respectively. Detection of these synthetic peptides was quantitative to over 100 µg/L by reference to the synthetic peptide calibration curves and at recovery rates, 76.6 ± 4.1%-104.8 ± 17.1% and 82.4 ± 2.0%-105.8 ± 5.3%, for GFIVQAR and QIPEQSR, respectively, when 1-1,000 µg of these peptides were spiked into a retort tomato sauce for pasta or dried instant soup. In combination with LC-MS/MS detection methods specific to other cereals containing gluten (rye, barley, and oats), the developed analytical approach was applicable to a wide variety of processed food commodities for food allergen labeling.

Potential ways for gluten contamination of gluten-free grain and gluten-free foods: the buckwheat case

Buckwheat has been reported to be responsible for gluten contamination in manufactured gluten-free foods (mGFFs) although it is inherently gluten-free (GF). It could happen through buckwheat grains contacting gluten-containing (GC) grains and surfaces contacted by GC grains during pre-manufacturing practices. To simulate grain contact, whole and broken GC grains (wheat, rye, barley, and oat) were mixed into buckwheat grains at the ratio of 2.5-10.0%. Grains were agitated in vessels with inner surfaces covered with buckwheat grain. Gluten was not detected in buckwheat grains contacting whole GC grains at all mixing ratios. It was not detected in the case of broken GC grains at the mixing ratio of 2.5% and oat grains at all mixing ratios. Gluten concentration increased with the increasing mixing ratio and the natural gluten concentration of broken GC grains. To simulate surface contact, GC grains were first agitated in galvanised steel vessels and then buckwheat grains were agitated together under the same conditions. Gluten was detected on galvanised steel surfaces contacted by whole and broken GC grains. It was not detected in buckwheat grains contacting the surfaces contaminated by whole GC grains. Gluten was detected in buckwheat grain in the case of the broken GC grains except for oats. Gluten concentrations increased with increasing natural gluten concentration of GC grains. Contamination of mGFFs could be linked to potential contact with buckwheat grain. This contamination issue could be resolved through regulations mandating the proof of being GF for ingredients used in the production of mGFFs.

Gluten contamination in labelled and naturally gluten-free grain products in southern India

Consumption of a gluten-free diet or avoiding exposure to gluten is the only feasible and effective treatment available for coeliac patients to date. Although many grains and their products are naturally gluten-free, the possibility of gluten cross-contamination must be considered. Since such data are not available for Indian markets, we carried out this pilot study (n = 160) to assess gluten contamination in various grain-based food products from the category of breakfast products, flours, and batters made from grain that are naturally gluten free. The gluten was extracted from samples using 60% ethanol and gluten analysis was carried out using a commercially available competitive ELISA, which utilises a monoclonal antibody. Nearly 9.8% of the products labelled as gluten-free and 36.7% of the products made from naturally gluten-free grain were found to contain gluten above 20 mg/kg. Among products made from naturally gluten-free grain, 35.9% of the flour samples and 85% of the oat samples (11.67-1830 mg/kg) were contaminated with gluten. In the case of flours, unbranded samples collected from local markets (70%) and directly from local mills (30%) showed gluten content above Codex safety levels (20-400 mg/kg). Among products labelled as gluten free (n = 51), only 5 samples showed gluten contamination above 20 mg/kg although levels were well within 100 mg/kg (32.5 ± 5.8). Our study suggests that there is a likelihood of gluten contamination in products that are sourced from local retailers and millers.