EFFECT OF MOISTURE CONTENT ON PHYSICAL AND ENGINEERING PROPERTIES OF SOME SEEDS

Abstract

Moisture content (MC)of seeds isconsidered one of the most influencing parametersaffectingthe machinerypropertiesofharvesting andpost-harvesting/handlingoperations.Therefore, this study is conductedto measure and realize the MC effect ofsome fine seeds are; cumin, sesame, aniseandcloverseeds on physical and engineering propertiesthat representanimportant parameter inresearch and development of agro-machinery (RDAM)doing harvesting, cleaning, grading and storing operations.Within MC average levels of 12-16% (w.b) for (cumin, sesame and anise) and 10-14% (w.b) for clover seeds, the obtained results revealed that physical propertiesin terms of length,width, thickness,mass of thousand seeds, volume of seed, arithmetic diameter, geometric diameter, flat surface area and transverse areaincreased by increasing ofmentioned MClevels for the all studied seeds, in contrast, the bulk densitydecreased.Also, percent of sphericitydecreased for sesame seeds but increased for clover seedsby increasing ofmentioned MC levels. While, for Cumin and Anise seeds it was increased with increasing of moisture content of seeds from 12-14% (w.b.) and decreased with increasing of moisture content of seeds to 16% (w.b.). On the other hand, engineering properties in terms of angle of repose, terminal velocity and coefficient of friction for(seeds, wood surface, galvanized sheet, plastic surface) increased by increasing of mentioned MC levels for the studied seeds. Terminal velocity values at (12, 14 and 16%) MC levels, were (5.45, 5.78 and 5.9 m/s) for sesame,(3.53, 3.93 and 4.15m/s) for cumin, (3.6, 3.75 and 3.93) for anise, respectively, and (8.4, 8.75 and 8.95 m/s) for clover at(10,12and 14%),respectively.