Gluten

Gluten is a group of storage proteins found in certain grains, notably wheat. It is composed mainly of two protein families, gliadins and glutenins. When mixed with water, gluten proteins form a viscoelastic network that gives dough its elasticity and gas-trapping ability, enabling bread and other baked goods to rise. Gluten is present in most wheat varieties and also in related grains such as barley, rye, and triticale; oats may contain trace gluten due to cross-contamination during processing.

Gluten strength and extensibility depend on the balance of gliadin and glutenin and on hydration and mixing. Glutenin molecules form a network that provides elasticity, while gliadin contributes extensibility, allowing dough to stretch as it traps gas produced by fermenting yeast. The resulting viscoelastic structure supports rising bread and a chewy texture in products such as pizza crust and pasta made from wheat gluten.

Health concerns related to gluten include celiac disease, an autoimmune condition in which ingestion damages the small intestine; wheat allergy, a IgE-mediated reaction; and non-celiac gluten sensitivity, characterized by symptoms without autoimmune damage. People with these conditions may follow gluten-free diets, which require careful substitution of gluten-containing ingredients. Gluten-free products are widely available, but some may differ in texture, nutrition, or price compared with traditional wheat-based foods.

Gluten is the primary protein in wheat and related grains grown and processed globally. In many jurisdictions, labeling standards distinguish gluten-containing foods from gluten-free products, using thresholds such as 20 mg per kilogram to define gluten-free status.