Glutenin is a type of protein found in wheat and other grains. It is one of the two main components of gluten, the other being gliadin. Glutenin contributes to the elasticity and strength of dough, making it essential for baking bread and other baked goods. When flour is mixed with water, glutenin forms long, stretchy chains that help trap air bubbles during fermentation. This process gives bread its chewy texture and allows it to rise. The quality and amount of glutenin in flour can significantly affect the final product, influencing its texture and structure.