Optimizing food for chewing efficiency

The 19th-century health faddist Horace Fletcher, nicknamed the Great Masticator, exhorted his followers to chew each bite of food so thoroughly that it became liquid. Although that advice is extreme, the impulse behind it is not without merit. Researchers have shown that the body more easily digests and more efficiently extracts nutrients from well-chewed food. In today’s age of processed foods, manufacturers could formulate their products to optimize material properties that promote efficient chewing.

As the basis for such optimization, a team led by Maria Charalambides of Imperial College London has developed a model of how a morsel deforms and breaks under compressive, tensile, and shear stresses. The researchers’ model starts with deformation behavior that depends on the rate at which loads are applied and then incorporates rules for mechanical failure based on material toughness. As shown in the figure, numerical simulations (right; color contours indicate strain) for starch-based pet-food samples successfully reproduced crack formation, crack propagation, and material failure seen in mechanical tests to mimic chewing (left). The case for materials engineering may be particularly strong for pet food because pets eat a largely processed diet. Next, Charalambides and her colleagues plan to incorporate into their model other effects, such as the degradation of mechanical properties by mixing with saliva. (C. G. Skamniotis, M. Elliot, M. N. Charalambides, Phys. Fluids, in press.)