Computer simulation of the breakdown of carrot particles during human mastication.

There are two separable aspects of the mastication of food particles. One aspect describes the probability of the selection of particles for fracture (selection); the other describes the manner of fragmentation of the particles (breakage). Definitions of these concepts were used to produce an approximate equation for food breakdown, which can be solved by iteration in a computer. Values for the selection and breakage functions, obtained from 10 human subjects using carrot as a test food, were used in a computer program which modelled mastication. The model assumed (1) that selection depended only on particle size (2) that fragmentation (range of fractions or sub-particles produced) was similar for all particles, whatever their size. Good agreement was found between the actual particle-size distributions produced by mastication and those distributions generated by the computer. Simulations predicted that the initial particle size of the carrot before mastication could be varied substantially, so producing similar particle-size distributions after 15 chews.