Cereals containing gluten

Gluten intolerance

Celiac disease or gluten intolerance is an autoimmune disease triggered by gluten, i.e. proteins present in wheat, rye and barley. The gluten proteins cause an inflammation of the mucosa in the small intestine leading to flattening of the mucosa and, when the illness is untreated, to malnutrition. Celiac disease is a life-long, permanent intolerance to gluten. Cereals like wheat, rye and barley must be excluded from the diet. As alternatives, gluten-free or very low gluten products, based on cereals, which have been rendered gluten-free like wheat starch and products based on i.e. maize, rice, millet or buckwheat can be used.

Oat which is not contaminated with gluten-containing cereals can be included in the gluten-free diet. A number of clinical studies indicate that most people (adults and children) with celiac disease tolerates oat.

Allergy to cereals

Cereals can also cause IgE-mediated allergic reactions. Such reactions are immediate or delayed after ingestion and their severity varies from mild to very severe like anaphylaxis. Gluten-free products i.e. those with a gluten level below 20 mg/kg are considered to be well tolerated by most people with IgE-mediated allergy to cereals.

Labeling

The presence of cereals containing gluten (i.e. wheat, spelt, kamut, rye, barley, oat or their hybridized strains) and products thereof must always be declared, see further in LIVSFS 2004:27 Livsmedelsverkets föreskrifter om märkning och presentation av livsmedel [in Swedish] (see link to the right).

Examples of methods of analysis

In commission regulation (EC) No 41/2009, whereas clause 11, is said that for the purpose of the regulation the Codex standard 118-1979, revised in 2008, should be taken appropriately into consideration. As method for determination of gluten in the Codex standard, the enzyme-linked immuno assay (ELISA) R5 Méndez method is given. Gluten/gliadin is quantified in the Méndez method in an enzyme immuno assay using a monoclonal antibody, R5, directed to the toxic peptide in secalin (the gliadin equivalent of rye). The limit of quantification is 5 mg gluten/kg (ppm).

Gluten can also be quantified with an enzyme immunoassay using a mono-clonal antibody to omega-gliadin. The limit of quantification is 3 mg gluten/kg (ppm).

Gluten can be detected in food samples using rapid methods, based on test strips, which are soaked in an extract of the food or in a swab sample extract. Such tests are only qualitative, i.e. the result is given either as gluten is present (positive) or gluten is not present (not detected) in the food extract. Positive results need sometimes to be confirmed with quantitative methods. It is very important that qualitative test kits don’t give false negative results.
 

Providers of test kit often have a validation protocol to be submitted with the test kit upon request. Laboratories using commercial assays must establish in house control of limit of detection and limit of quantification in actual matrices even if the test has been validated by the provider.

Celiac reactions on cereals / Doses

The concentrations of gluten proteins that have been detected in food products causing reactions among coeliacs are listed below. 

* The same product causing the allergic reaction below
** Consume only products without wheat starch
 

Allergic reaction to cereals / Dose

The lowest dose of gluten protein that elicitates an allergic reaction is not known. The concentrations of gluten proteins that have been detected in food products causing allergic reactions are listed below.