Effect of moisture content on physio-mechanical properties of coriander seeds (Coriandrum sativum)

Abstract

Study to determine physical and mechanical properties of seeds at different moisture content is necessary for the design of equipment to handle, process, transport, and store the same.  The physical properties of coriander seeds have been evaluated as a function of seed moisture content, varying from 8% to 16% (w.b.). In the moisture 11.2%, seeds major, minor and medium dimensions were 5.062, 3.27, and 3.404 mm respectively. Sphericity of the seeds was found to be 0.757 with a surface area of 46.167 mm2.  One thousand seed weight increased linearly from 8.89 to 9.826 g when the moisture content increases from 8.5 to 15.89% (w.b.).  The true density of coriander seeds decreased when the moisture content increased 8.73 to 12%, from this point, true density increased with increasing moisture content while the bulk density of coriander seeds varied initially from 260 to 245.5 kg m-3 in 8 to 15% MC (w.b.).  As the moisture content of seeds increased the bulk density decreased.  Also, the porosity started at 24.284% and reduced nonlinearly to 22.88% at 11.50% seed moisture content then increased nonlinearly up to 27.466% at 16.67% seed moisture content.  Static coefficient of friction was observed lowest for stainless steel sheet and maximum for galvanized iron sheet.  The angle of repose increased linearly from 25.5° to 30.1° with the increase in moisture content.  Mechanical properties was found to be a function of moisture content, as moisture content of the product increased failure force reduced but failure deformation increased.

Keywords: physical properties, mechanical properties