Anisotropic Relaxation Properties of Pear

The relaxation phenomena are critical aspects of fruit rheological properties. Little detailed information is available on the non-homogeneous and anisotropic relaxation properties of fruits. The objective of this study was to determine the effects of specimen orientation and location with the pear on the equilibrium modulus, the decay modulus, time of relaxation, and specific viscosity in the relaxation model. The stress relaxation tests were performed on Dangshan pear using the Instron universal testing machine. The decay modulus, the equilibrium modulus, time of relaxation, and specific viscosity in the relaxation model are significantly influenced by specimen orientation, latitude, and depth. The longitude of the specimen and initial deformation are not significant.