The moisture dependent physical and mechanical properties of whole lentil pulse and split cotyledon

Some physical and mechanical properties of lentil whole grain/pulse and dhal (dehusked split pulse), at different moisture contents were determined. Among the physical properties, size, sphericity, roundness, average surface area, bulk density and void fraction were determined. Bulk densities of whole pulse were between 785 and 831 kg m^?3, whereas for dhal they were between 741 and 840 kg m^?3 and bulk density decreased as moisture content was increased for both the whole grain and the dhal. The compression behaviour was judged by determining the firmness and the linear elastic limit, of which the former decreased with moisture content but the linear elastic limit increased. A method is proposed to calculate the total surface area of dhal and whole pulse. Photomicrographs showed the thickness of the outer seed coat to be between 25 and 65 microns.