Estimation of the mechanical properties of individual brittle particles from their bulk compressibility

Two puffed cereal particles were compressed both individually and in cells of different diameters and heights. The degree of jaggedness of their force-displacement curves were expressed in terms of their apparent fractal dimension determined from the Richardson plot and by the box counting method (Kolmogorov's dimension). Plots of the degree of jaggedness versus cell diameter and height produced approximately planar relationships in a three dimensional space. Their extrapolation to the individual panicle characteristic dimensions gave jaggedness values in agreement with those determined experimentally on the individual particles. This demonstrates that it is possible, at least in certain products, to assess the "brittleness" of individual particles from their bulk compressibility pattern. The same procedure could also be used to estimate the particle "stiffness" expressed in terms of the force at a preselected displacement level (e.g., 15 or 25%).