Gluten

Gluten is a structural protein complex naturally found in certain cereal grains, primarily wheat, barley, rye, and some cultivars of oat, as well as cross-hybrids such as triticale. In wheat, gluten refers specifically to the elastic network formed by two main protein groups: gliadin and glutenin. When water is added and the mixture is kneaded, these proteins bond—glutenin molecules cross-link via disulfide bonds to create a submicroscopic network, while gliadin contributes viscosity and extensibility. This network gives dough its elasticity, allowing it to rise and retain its shape, and often results in a chewy texture in baked goods. Gluten constitutes 75–85% of the total protein in bread wheat. The homologous storage proteins in barley are called hordeins, in rye secalins, and in oats avenins; all are collectively referred to as gluten. In baking, the strength and elasticity of gluten are measured using a farinograph. Higher gluten content, found in hard wheat flours, produces chewier doughs suitable for pizza and bagels, while lower gluten flours yield tender pastries. Kneading promotes gluten strand formation and cross-links, increasing chewiness; very wet doughs left to rise for long periods require no kneading. Shortening inhibits cross-links, aiding in flaky products. In industrial production, wheat flour is kneaded to agglomerate gluten, which is then collected, dried, and milled into a powder. This added gluten can improve dough volume, structural stability, and chewiness. Gluten is also used as a base for imitation meats, such as seitan, where it absorbs surrounding liquid and becomes firm when cooked. However, gluten can trigger adverse inflammatory, immunological, and autoimmune reactions in some people, including celiac disease, non-celiac gluten sensitivity, dermatitis herpetiformis, and gluten ataxia, all of which are managed with a gluten-free diet.