Modeling of some physical properties of watermelon (Citrullus Lanatus (THUNB.) MANSF.) seeds depending on moisture contents and mineral compositions

In this study, mineral contents for human diet and some physical properties that are important for the design of equipments for sowing, harvesting, processing, transportation, sorting, separation and packaging of watermelon seed (cv. Diyarbak{dotless}r) grown in South Eastern Turkey were determined. Those properties were evaluated as functions of moisture content in the moisture range from 6 to 28% dry basis (d.b.) for the rewetted watermelon seed. Results showed the average length, width, thickness, the geometric mean diameter, sphericity, 1000 seed weight, unit mass and volume of the seed were found as 10.8, 6.8, 2.3, 5.5 mm, 51.5%, 94.10 g, 0.089 g and 0.13 cm3, respectively. The bulk density decreased from 446.4 to 417.68 kg m-3, true density increased from 639 to 732 kg m-3, porosity increased from 30.79 to 45.46%, projected area increased from 0.42 to 0.60 cm2, terminal velocity increased from 4.45 to 4.82 m s-1 and the rupture force decreased from 9.94 N to 2.52 N, the sphericity increased from 51.48 to 52.31% while the moisture content of watermelon seed increased from 6 to 28% d.b. Mineral contents and chemical compositions of seeds including K, P, Ca, Na, Zn, Fe, crude protein, crude oil, crude fiber and total ash were 0.41, 0.74, 1.53, 0.062, 0.20, 0.13, 345.5, 520.0, 55.0 and 33.5 g kg-1, respectively. The physical properties varied as functions of moisture content for the rewetted watermelon seed. Those variations were evaluated as mathematical model.