ABSTRACT:Technical information and data on the physical and mechanical properties of agricultural and animal products are necessary to design various equipments for agriculture and industry. In this study some physical properties such as mass, length, diameter, geometric mean diameter, surface area, sphericity, volume, coefficient of friction and packaging coefficient were determined for Japanese quail eggs. Furthermore, the mechanical behaviour of Japanese quail eggs was determined in terms of average rupture force, deformation and toughness (energy absorbed by the Japanese quail eggs per unit volume). Egg samples were compressed along their X and Z-axes.The average values of their mass, length, width, shell thickness, geometric mean diameter, surface area, sphericity, volume and packaging coefficient were measured to be 12.69 g, 34.87 mm, 26.20 mm, 0.27 mm, 28.82 mm, 2 608.5 mm 2 , 1.10, 359.17 mm 3 , 0.469, respectively. The values of the coefficient of friction for quail eggs on the surfaces of plywood, glass, galvanized steel and fibreglass were 0.301, 0.282, 0.274 and 0.266, respectively. The highest rupture force, deformation and toughness were obtained when Japanese quail eggs were loaded along their X-axis. Compression along the Z-axis required the least compressive force to break the eggs as compared to the other compression axes. Rupture force, deformation, absorbed energy and toughness for the X-front axis were determined to be 10.51 N, 1.5 mm, 7.88 Nmm and 0.219 Mj/mm 2 , respectively.

The mechanical properties of Nonpareil versus Gulcan 101‐23 almond cultivars that have different shell properties were loaded between two parallel plates to determine the rupture force, rupture energy, rupture power requirement, toughness and firmness. The tests were carried out with three moisture contents, namely, 7.2, 22.9 and 33.6% wet basis and three loading axes (x, y, z). Physical characteristics of the almond cultivars such as length, width, thickness, geometric mean diameter, sphericity, volume, surface area and weight were determined. Physical properties of both cultivars increased as a numerical by increasing moisture content. The highest rupture force in all moisture content levels was obtained for almond pit loaded along the y‐axis. In addition to rupture force, values of absorbed energy, toughness, power requirement and firmness were calculated as mechanical properties. The maximum force required to initiate pit rupture was found as maximum 554.3 N at y‐axis for 7.2% moisture content and minimum 126.9 N at x‐axis for 33.6% moisture content for Gulcan 101‐23 cultivar. These values were determined as 53.3 and 11.2 N, respectively, for Nonpareil cultivar. Rupture force, absorbed energy, toughness, power requirement and firmness decreased with an increase of moisture content. The difference between mechanical properties of Nonpareil versus Gulcan 101‐23 almond cultivars was found to be highly significant (P < 0.001). PRACTICAL APPLICATIONS As almond production increases in the world, almond processes are performed by hand or by using old techniques. Therefore, major quality loss during harvesting and postharvesting processes of almonds occurs. The most critical and delicate operation in postharvesting processes is pit cracking to extract the fragile whole edible kernel from the almond pit. This process is still carried out by hand or by using an apricot cracking equipment. But this is not the right process because shell hardness of almond pit changes in relation to almond cultivars. While some almond pits can be cracked using high power and some apparatus, some of them can be cracked even by hand easily. The cracking operation causes damage and broken kernels because of the excessive mechanical forces. The extent and type of damage depend on the physical characteristics, cultivar and applied force. For this reason, systems must be designed while taking these criteria into consideration to prevent inadequate applications.

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