Mechanical behaviour of apricot pit under compression loading

The mechanical properties of apricot pit were determined in terms of average rupture force, deformation and toughness (energy absorbed by the pit per unit volume). Samples at various moisture contents were compressed along the X-, Y-, and Z-axes. The X-axis is the loading axis through the length dimension, while the Y-axis is the transverse axis containing the minor dimension (width) at right angles to the X-axis, and Z-axis is the transverse axis containing the minimum dimension (thickness). Physical characteristics of apricot pit and its kernel such as mass, dimensions and geometric mean diameter were determined. The experiments have shown that rupture force, deformation and toughness generally decreased in magnitude with an increase in moisture content from 6.38% to 39.33% db. The highest rupture force, deformation and toughness in all moisture content levels were obtained for apricot pit loaded along the X-axis. Compression along the Y-axis required less compressive force to extract the kernel as compared to other two compression axes. In this study, it was observed that there was no kernel breakage for loading along the X- and Y-axes. Especially, at higher moistures, there was always the tendency of the kernel breakage for loading along the Z-axis. The results provide useful data to be used by engineers in the design of suitable apricot pit cracking machine. (C) 2004 Elsevier Ltd. All rights reserved.