Moisture-dependent Physical and Thermal Properties of Sericea Lespedeza Seeds

Abstract

Abstract. The bioactivity of Sericea lespedeza (SL) condensed tannins, including suppression of gastrointestinal nematodes, has contributed to a surge in interest of use of this plant in livestock production systems worldwide. Physical and thermal properties of SL seeds (AU Grazer™ and Serala cultivars) were determined as a function of moisture content for a moisture range from 8.57% to 26.53%, wet basis. The length, width, arithmetic mean diameter, geometric mean diameter, surface area, volume, and 1000 seed mass of both the seeds increased as the moisture content increased. Bulk density and unit density decreased as the moisture content increased. The sphericity of SL seeds decreased with increasing moisture content. Serala seeds were characterized by a higher aspect ratio than AU Grazer™. The angle of repose of SL seeds increased, while the compressibility index decreased in the moisture range. For color, the L* values of SL seeds decreased while the a* values increased with the increase in moisture content. A decrease in the b* values was insignificant. The thermal conductivity and specific heat of SL seeds decreased, whereas, thermal diffusivity increased as the moisture content of SL seeds increased. Serala seeds were characterized by higher values of thermal conductivity and volumetric specific heat than AU Grazer™. Keywords: Engineering properties, Moisture content, Physical properties, Seeds, Thermal properties.