on Dynamic Viscoelasticity of Korla Pear Tissue

Abstract:

Viscoelastic properties of Korla pear (Pyrus bretschneideri rehd) tissue osmotically treated in iso-, hypo- or hypertonic sucrose solutions were investigated using oscillatory shear and creep-recovery tests. Results indicate that storage moduli (G′) is much higher than loss moduli (G″) over the entire frequency range. Both G′ and G″ show frequent independent, but increase with the increasing of turgor. In creep testing, the creep compliance responses of low, normal and high turgor tissues were characterized by a generalized Kelvin-Voigt model with six elements. The instantaneous (J0), retarded compliance (J1 and J2) and steadystate fluidity (1/η0) increased as turgor was reduced. By scanning electron microscopy (SEM), many rheological parameters (G″, G′, J0, J1, J2 and 1/η0) show the marked changes among the three turgor levels, which relates with the changes of cells and intercellular spaces due to the turgor manipulation.