chains To do this they require the availability of oxidizing agents — oxygen in the air, certain substances produced by yeasts, or “dough improvers” (p 529) added by the flour manufacturer or baker The long, coiled middle stretch of the glutenin molecule consists mainly of amino acids that form weaker, temporary bonds (hydrogen and hydrophobic bonds) with similar amino acids Glutenin chains thus link up with each other end-to-end to form super-chains a few hundred glutenins long, and coiled stretches along their lengths readily form many temporary bonds with similar stretches along neighboring gluten proteins The result is an extensive interconnected network of coiled proteins, the gluten Gluten Plasticity and Elasticity The gluten of the bread wheats is both plastic and elastic; that is, it will change its shape under pressure, yet it resists the pressure and moves back toward its original shape when the pressure is removed Thanks to this combination of properties, wheat dough can expand to incorporate the carbon dioxide gas produced by yeast, and yet resists enough that its bubble walls won’t thin to the breaking point Gluten plasticity results from the presence of the gliadin proteins among the glutenins; because they’re compact, the gliadins act something like ball bearings, allowing portions of the glutenins to slide past each other without bonding Elasticity results from the kinked and coiled structure of the interconnected gluten proteins Kneading unfolds and aligns the protein molecules, but there are still loops and kinks along their lengths Stretching the dough straightens out these loops and kinks, but when the pressure is relieved, the molecules tend to revert to their original kinkiness In addition, the coiled spring-like structure of individual proteins can extend and store some of the energy of ... portions of the glutenins to slide past each other without bonding Elasticity results from the kinked and coiled structure of the interconnected gluten proteins Kneading unfolds and aligns the protein molecules, but... unfolds and aligns the protein molecules, but there are still loops and kinks along their lengths Stretching the dough straightens out these loops and kinks, but when the pressure is relieved, the molecules tend to revert to their original kinkiness... by yeast, and yet resists enough that its bubble walls won’t thin to the breaking point Gluten plasticity results from the presence of the gliadin proteins among the glutenins; because they’re compact, the gliadins act something like ball bearings, allowing