Textural properties of food used in studies of mastication.

Foods are known to influence jaw elevator muscle activity in chewing. With the long-range goal of gaining insight into force control and modeling muscle recruitment, these initial experiments were performed to determine the textural properties of commonly used test food. Experiments were carried out by means of a standard Instron instrument, equipped with a compression cell. A stylus with 45-degree cuspal angulation and an opposing copper-plated lower arch was used for approximation of the natural situation. The breakage force characteristics of a single peanut, a carrot cube, beefstick, and monkey chow were determined. The peanut demonstrated the steepest and beefstick the least steep force build-up, with breaking forces of 104 N (Newtons) for monkey chow, 66 N for the carrot, and 52 N for the peanut. No clear breakage point was found with beefstick; the force build-up showed an initial plateau at 25 N, which was followed by a significantly steeper force increase to peak. We conclude that each of the test foods commonly used in studies of mastication had particular breakage characteristics in terms of its force-time curve.