Viscoelastic-plastic behavior of single tomato mesocarp cells in high speed compression-holding tests

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Colleges, School and Institutes


The micromechanics of isolated tomato fruit cells were investigated by microcompression-holding. Covering the cells with deionized water after isolation caused no significant volume changes, suggesting that cells suspended in water for compression testing were representative of those in the original tissue. The viscoelastic-plastic behavior of such cells was characterized by compression at 4900 ± 200 μm s− 1, then holding. Although the cells were generally not spherical initially and some cell deformation appeared to be local, the force-time data were fitted by the Hertz–Maxwell model for relaxation of viscoelastic spheres. The force at 15% deformation, instantaneous and equilibrium elastic moduli, yield strength, and first and second relaxation times were 2.5 ± 0.6 mN, 0.6 ± 0.3 MPa, 0.22 ± 0.08 MPa, 0.03 ± 0.01 MPa, 0.48 ± 0.05 s, and 0.033 ± 0.004 s, respectively. These parameters showed little sensitivity to several reasonable definitions of cell size nor to changes in the (assumed) Poisson's ratio.


Original languageEnglish
Pages (from-to)44-50
JournalInnovative Food Science and Emerging Technologies
Early online date27 Jan 2016
Publication statusPublished - Apr 2016


  • Tomato fruit, Single cells, High speed compression, Viscoelastic-plastic, Hertz–Maxwell model