LAUSR

Abstract Fruit purees are concentrated suspensions of highly deformable, non-spherical particles. These particles are delimited by a plant cell wall and filled with the continuous phase. They can shrink under stress, as it occurs with the increasing concentration in particles, making difficult the determination of their real volume fraction and the understanding of their rheological properties. Usually, the rheological behavior of plant suspensions is described by three concentration domains. We show here on apple puree that beside the complexity of such system, the concentration dependence of the viscosity can be described by one single model over the full range of concentration investigated. The model, originally developed for soft colloids, fits accurately the experimental results obtained on ground purees of several particle size distributions (either monomodal or bimodal) and in several continuous phases. It considers the particles stiffness and asphericity, but also highlight the effects of the continuous phase properties, for example through lubrication.