Mechanical Characterization of Individual Instant Coffee Agglomerates

Abstract

Agglomerated instant coffee particles were compressed individually with a TA‐XT2 Texture analyzer. Up to about 57% equilibrium relative humidity (ERH), the force‐displacement curves were very jagged. The slopes of plots of highest local force peaks vs deformation were used as a measure of agglomerate stiffness. The degree of jaggedness of the original force‐displacement curves, a brittleness measure, was quantified in terms of an apparent fractal dimension using two algorithms. Stiffness and brittleness were little affected by moisture at ERH levels in the range 11 to 52%. At ERH 57% both decreased sharply, indicating plasticization of the soluble material.