GLUTENREDUCED BEERS MADE WITH

BARLEY BY SYLVIE VAN ZANDYCKE

C

eliac disease (CD) is an autoimmune condition mainly characterized by the destruction of the small intestinal villi, reducing nutrient absorption and causing various symptoms including diarrhea, headaches, fatigue, and neurological disorders. CD has also been associated with increased rates of intestinal cancer and other malignancies. It is believed that 1 percent of the Western world suffers from CD, although a large percentage of the population remains undiagnosed, what is referred to as the “celiac iceberg.” Diagnosis is possible through blood tests targeting specific antibodies and biopsies looking for intestinal damage to the villi. The presence of the DQ2 and DQ8 genes indicates a susceptibility to the disease, but it may not develop in all subjects carrying those genes. Absence of those genes, however, rules out development of the disease altogether. CD is often triggered by a psychological or physical trauma. There is no cure for CD, so this means a lifelong gluten-free diet for people affected. Non-celiac gluten sensitivity is in contrast a non-autoimmune and non-allergic disorder. Symptoms are similar to CD but are not considered life-threatening. Non-celiac gluten sensitivity has been defined as one or more of a variety of immunological, morphological, or symptomatic manifestations that may also be shared by celiac disease and irritable bowel syndrome. Non-celiac gluten sensitivity affects reportedly 10 percent of the Western world, with likely just as many undiagnosed subjects.

GLUTEN PROTEINS IN GRAINS AND BEER Gluten is a storage protein found in wheat, barley, and rye and is composed of two fractions: prolamins and glutenins.The prolamin fraction (termed gliadin in wheat, hordein in barley, and secalin in rye) is composed

of mostly proline and glutamin amino acids and is responsible for causing unwanted reactions in gluten-intolerant people. Allergenic gluten peptides are insufficiently degraded by gastrointestinal enzymes (proteases), leaving intact epitopes; those immunotoxic epitopes bind to celiac-specific cells (antigen) to stimulate T cells and create the symptoms described above. Beer is mostly made of barley malt and therefore contains gluten, rendering it unsuitable for people with the intolerance; however it has been observed that a large majority of proteins are eliminated during the brewing process at mashing (especially), boiling, fermentation, and maturation due to action of proteolytic enzymes and precipitation. Addition of process aids can also contribute to reducing the levels of gluten proteins even further to reach undetectable levels when measured using immunological tests1.

MEASURING GLUTEN IN BEER Accurately measuring gluten is key to producing a safe product for gluten-intolerant individuals. Sensitivity to gluten varies considerably among affected people. For individuals diagnosed with CD, damage can occur at levels as low as 10 mg per day of gluten; however, most damage occurs at 50 mg per day. An intake of less than 10 mg per day of gluten is recommended to avoid negative effects. As such, the Codex Alimentarius states that if gluten is not present at more than 20 ppm, exposure in a product would remain below 10 mg per day2. The Codex Alimentarius also refers to the Sandwich R5 Enzyme-Linked Immunoassay (ELISA) to measure gluten in food; the monoclonal R5 antibody recognizes the QQPFP (glutamine-glutamine-prolinephenylalanine-proline) motif, among others. QQPFP is a common repetitive sequence present in all prolamins and allergenic epitopes. However, the Sandwich R5 test is

not suitable for all types of food, especially food containing hydrolyzed gluten such as beer, malt extract, sourdough, and starch. The ELISA test has been further developed over the last few years to accurately measure gluten in beer where it is partially hydrolyzed, and small fragments of hordeins should be detected if they contain allergenic epitopes. The recommended ELISA test for beer is the R5 Competitive, which can recognize as little as 1 epitope.The second (and improved) generation of ELISA standards consists of a peptic/tryptic digest of wheat, rye, and barley; the limit of detection and quantification were of 1.36 and 5.0 ppm respectively3. It is standard practice to multi-

“It has been observed that a large majority of proteins are eliminated during the brewing process at mashing (especially), boiling, fermentation, and maturation due to action of proteolytic enzymes and precipitation.”

Figure 1: Practical example of Brewers ClarexTM usage in the brewing process to degrade gluten

PSEP (Brewers Clarex™) 2-3 g/hl

A UNIQUE ENZYME

Wort coming in

Green beer coming out

100+ ppm gluten