Figure 1.

(A) Schematic drawing of the elastometer used for biaxial tensile testing. A hydrostatic pressure is generated by displacing silicone oil using a piston. An increase in pressure causes the ESs of sweet cherries to bulge outwards. The system pressure and height of bulging are measured using electronic pressure and displacement transducers, respectively. (B) The contour of the bulged ES was determined from a cross-section of an imprint and digitized. A range of geometrical models (spheroid, paraboloid and ellipsoid) were fitted to the contour.