Scientists looking at dough performance usually employ rheological methods, which measure the deformation of matter. Ultrasound probes matter’s interior and, in the case of dough, provides information about the bubbles that determine finished product texture.

Although rheology is usually the cereal scientist’s choice, ultrasound deserves consideration, too, said Martin Scanlon, Ph.D., professor of food technology, department of food science, University of Manitoba, Winnipeg. He recently explained how low-intensity ultrasound could help predict dough’s mechanical performance during mixing, sheeting and extrusion.

Ultrasound methods measure how fast sound propagates through a substance, in this case, through dough, and how effectively it dissipates. It can probe the size and prevalence of bubbles because their density differs from the dough matrix. Doughs with a greater number of bubbles are softer, and doughs developed by sheeting will have larger bubbles.

“Bubble sizes in dough can potentially be determined using ultrasonic techniques,” Dr. Scanlon said. “All rheological tests on dough are affected by bubbles, and more importantly for the breadmaking process, all dough process steps are affected by the bubbles a dough contains.”