Effect of Moisture Content on Terminal Velocity, Compressive Force and Frictional Properties of Melon Seeds

The investigation of the moisture dependence of engineering properties of melon seeds is essential for the design of its processing equipment. Selected engineering properties of two varieties of melon (Citrulus lanatus- Variety A and Solanum sp.- Variety B) were determined at a moisture content range of 4.06 to 16.81% (dry basis). An increase in the moisture content resulted in a directly proportional increase in all the properties for the two varieties except for the compressive force which decreased as the moisture content increased. The minimum and maximum value of emptying angle of repose was 21.37 0 for variety B at 4.06% (d.b.) and 24.26 0 for variety A at 16.81% (d.b.). The minimum value for coefficient of friction was 0.19 for Variety B against glass at moisture content of 16.81% (d.b.) and a maximum corresponding value of 0.36 for Variety A against plywood at 4.06% (d.b.), respectively. Variety A seeds had minimum value of terminal velocity of 4.53 m/s at 4.06% (d.b.), and maximum corresponding value was 5.1 m/s at 16.81% (d.b.) for Variety B. The minimum and maximum value of the compressive force was 5.91N at 4.06% (d.b.), and corresponding value was 2.01N at 16.81% (d.b.) and both were obtained from Variety A. Analysis of variance (ANOVA) showed that the coefficient of friction and compressive force for both varieties of melon seeds were affected significantly by moisture content and/or variety (P<0.05). Relationship between the properties and moisture content were expressed by linear equations.