Assessment of deformability of soft plant cells by 3D imaging
Résumé
Purees of fruit and vegetables are concentrated suspensions of plant particles. To elucidate the link between process and texture, it is necessary to understand their rheological behaviour, which is related to the plant cell volume fraction. Nonetheless, the concept of plant particle volume has yet to be clearly defined. From a physical point of view, plant cells can be considered soft, deformable, and compressible particles that tend to decrease their volume under stress or when the concentration increases, making the volume fraction difficult to determine. To the best of our knowledge, the ability of cells to compress themselves has never been shown directly in processed fruit and vegetables. Using confocal microscopy and three-dimensional (3D) reconstruction, we developed a protocol for determining the volume of cells in a concentrated suspension. Four suspensions varying in cell wall content were analysed. The cell volume decreased only in highly concentrated suspensions. We demonstrated by direct observation the ability of plant particles to compress and decrease their volume when the concentration of the suspension increases.