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

Abstract

Moisture content (MC) of seeds is considered one of the most influencing parameters affecting the machinery properties of harvesting and post-harvesting/handling operations. Therefore, this study is conducted to measure and realize the MC effect of some fine seeds are; cumin, sesame, anise and clover seeds on physical and engineering properties that represent an important parameter in research 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 properties in terms of length, width, thickness, mass of thousand seeds, volume of seed, arithmetic diameter, geometric diameter, flat surface area and transverse area increased by increasing of mentioned MC levels for the all studied seeds, in contrast, the bulk density decreased. Also, percent of sphericity decreased for sesame seeds but increased for clover seeds by increasing of mentioned 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, 12 and 14%), respectively.