for the analysis of baked goods. During the 25th session of the Codex Committee on Nutrition and Foods for Special Dietary Uses in 2003, the R5-Mendez ELISA method, which entails the use of reducing/denaturing conditions, was forwarded to the Codex Committee on Methods of Analysis and Sampling for endorsement (Codex Alimentarius Commision, 2003). These ELISA test kits cross-react, to differing degrees, with prolamins derived from wheat, rye, and barley. None of the test kits cross-reacts with protein extracts from oats (Gabrovská et al., 2004; Nonaka, 2004; Abouzied, 2004; Brewer et al., 2004). As such, the ELISA test kits do not provide protection to individuals with celiac disease who are sensitive to oats (Peraaho et al., 2004; Storsrud et al., 2003; Arentz-Hansen et al., 2004; Lundin et al., 2003). Proficiency testing studies conducted by the Food Analysis Performance Assessment Scheme (FAPAS®) have shown variability between the prolamin ELISA test kits (Central Science Laboratory, FAPAS Series 27 Round 05, Report No. 2705, 2003), indicating that further validation studies for these kits need to be carried out under comparable conditions. In addition to ELISA test kits, two of the manufacturers, Tepnel BioSystems and R-Biopharm, market lateral flow devices for the detection of gluten. To date, neither of these has been validated.
At this time there is no correlative information on the efficacy of using these tests to predict or help prevent adverse effects in individuals with celiac disease.
I. Gluten-Free Labeling Although gluten-free diets are considered the only effective treatment for individuals with celiac disease, it has been recognized that it is difficult, if not impossible, to maintain a diet that is completely devoid of gluten (Collin et al., 2004). Therefore, several attempts have been made to define gluten-free in regulatory contexts. Efforts by the Codex Alimentarious to define an international standard for “gluten-free” labeling date back to 1981. At that time, due to the lack of sensitive, specific analytical methods, a threshold value of 0.05 g nitrogen per 100 g dry matter was set for wheat starch, on the assumption that wheat protein would be the only source of nitrogen in starch (Codex Standard 118-1981). The Codex Committee on Nutrition and Foods for Special Dietary Uses is developing a revised standard. The current draft proposal would define three categories of gluten-free foods: processed foods that are naturally “gluten-free” ( 20 ppm of gluten), products that had been rendered “gluten-free” by processing ( 200 ppm), and any mixture of the two ( 200 ppm). The Australia New Zealand Food Agency (ANZFA) defines gluten to mean “the main protein in wheat, rye, oats, barley, triticale and spelt relevant to the medical conditions, Coeliac disease and dermatitis hepetiformis.” ANZFA recognizes two classes of foods, gluten-free foods (“…no detectable gluten”) and low-gluten foods (“…no more than 20 mg gluten per 100 gm of the food”) (ANZFA Food Code Standard 1.2.8). The Canadian standard for “gluten-free” is more general, simply stating that “No person shall label, package, sell or advertise a food in a manner likely to create an impression that it is a "gluten-free" food unless the food does not contain wheat, including spelt and kamut, or oats, barley, rye, triticale or any part thereof ” (Canadian Food and Drugs Act Regulation B.24.018).
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