Mechanical properties and microstructure of Fuji apple peel and pulp

Abstract

The mechanical characteristics of apples are crucial to the mechanization of apple production. In this study, the mechanical characteristics of the Fuji apple with the largest crop yield were studied by testing the tensile strength, compression strength, shear strength, bending strength, hardness, friction coefficient, and microstructure. The obtained minimum values of the elastic modulus, yield strength, shear strength, bending strength, and compressive strength were 5.0 ± 0.52, 2.2 ± 0.15, 0.45 ± 0.02, 0.062, and 2.4 ± 0.21 MPa, respectively, all located at the maximum radial radius of the pulp. The hardness decreased gradually with storage time: the hardness of the pulp after 28 days was 0.16 ± 0.02 MPa. The static friction coefficients against TPU (Thermoplastic Urethane) rubber and aluminum alloy materials were 0.88 ± 0.03 and 0.14 ± 0.003, respectively. The microstructure of the peel and pulp changed significantly after damage. The regular shape was destroyed, and the cells deformed and ruptured. The changes in the microstructure were consistent with the changes in the macromechanical properties, so the reliability of the test data could be verified.

Keywords

• Apple production
• Agricultural mechanization
• Mechanical properties
• Microstructure
• Macrostructure