Deformability of soft plant cells accessed by 3D images. Leverrier C. et al. 2017 (Accepted for publication in Food Biophysics).
Purees of fruit and vegetables are concentrated suspensions of plant particles. To make the link between process and texture, it is necessary to understand their rheological behaviour which is related to the plant cell volume fraction. However, plant particle’s volume fraction is not clearly defined yet. From a physical point of view, plant cells can be considered as soft, deformable and compressible particles, which are susceptible to decrease their volume under stress or when the concentration increases, making the volume fraction difficult to determine. To our knowledge, the ability of cells to compress themselves has never been shown directly from processed fruit or vegetable. Using confocal microscopy and 3D reconstruction, we developed a protocol to determine the volume of cells in concentrated suspensions. Four suspensions varying in cell wall content were analysed. Cells’ volume only decreases in highly concentrated suspensions. We demonstrate by direct observation the ability of plant particles to compress and decrease their volume when the concentration of the suspension increases.