Investigating protein changes during dough mixing

When we mix dough, gluten proteins undergo changes to their size and shape, which affect dough handling properties and the quality of the end product. The Canadian Grain Commission’s Grain Research Laboratory, in collaboration with a Canadian wheat customer in Japan, studied how the mixing process affects dough behavior and how this knowledge could be used to improve the quality of bread and other wheat products.

Dough mixing develops a gluten protein network that gives the dough its strength and stretchiness. Gluten proteins interact with each other and bind together through non-covalent bonds. A non-covalent bond is a chemical bond between molecules that don’t share electrons and instead include more variations of electromagnetic interactions. This function of non-covalent bonds makes them an important contributor to dough structure. However, the role that non-covalent bonds play in dough formation, including the changes the proteins experience, has proved difficult for scientists to analyze.

To examine this relationship between non-covalent bonds and protein changes, our researchers sampled dough at different stages of mixing. They extracted the proteins from each dough sample, then applied a series of solutions to gradually weaken the non-covalent bonds and examined how the proteins changed at various mixing times. The weakening of the bonds allowed the proteins to dissolve easily since they were not as tightly connected to surrounding proteins. Therefore, the testing demonstrated that proteins’ interactions through non-covalent bonds dictate protein changes during dough mixing.

These results provide a basis for future research into which type of non-covalent bond is most responsible for protein changes during mixing. Understanding the chemistry of dough formation and properties can help to find ways to improve how flour performs during mixing, such as selecting a suitable wheat type, applying additives and altering the processing conditions. Efforts like these help to maximize the quality and value of wheat products.