Effect of Moisture Content on Physical Properties of Fluted Pumpkin Seeds

Abstract

A number of physical properties of fluted pumpkin seeds were evaluated to obtain data for the mechanization of the crop’s production and the design of its postharvest equipment. The properties were investigated at five different moisture content levels, namely 51.50, 53.60, 58.03, 64.02, and 67.30% (wet basis). Standard methods, as reported in the literature for other agricultural products, were used to investigate the relationship between these physical properties and moisture content. Linear regression equations were used to express the relationships between moisture content and the physical properties of the seeds. The seed dimensions increased with an increase in moisture content. The geometric and arithmetic mean diameters increased from 2.43 to 2.65 cm and 2.65 to 2.82 cm, respectively, as moisture content increased. The true and bulk densities decreased from 1.08 to 0.97 g/cm3 and 0.98 to 0.69 g/cm3, respectively, with an increase in moisture content. The angle of repose of the seeds reduced from 40.79° to 36.05° as moisture content increased from 51.50 to 67.30%. The coefficient of friction increased with an increase in moisture content from 0.67 to 0.87, 0.59 to 0.75, and 0.58 to 0.63 for wood, steel, and glass surfaces, respectively. The results are of value for the development of equipment for operations, such as planting, harvesting, conveying, cleaning, separation, shelling, de-hulling, milling, packaging, storing, drying, and oil extraction.