Strength properties and dynamic coefficient of friction of popcorn kernels were evaluated as a function of moisture content in the range of 7.78-16.72 g/100 g dry solids. In order to determine strength properties of the kernels that are in terms of deformation at rupture point, rupture force, energy absorbed, hardness, and toughness of the popcorn kernels were quasi-statically loaded between two parallel plates. To determine frictional properties, friction tests were performed on aluminum, steel, and fiberglass surfaces. The values related to the strength properties, in general, decreased as the moisture content increased. On the other hand, the dynamic coefficient of friction of the popcorn kernels increased with increasing moisture content.

A b s t r a c t. The seeds of two safflower cultivars were investigated in order to determine their frictional and aerodynamic properties as a function of moisture content. The coefficients of dynamic friction of cultivars on aluminium, plywood, fibreglass and steel surfaces increased by 87, 56, 78, and 129% for cv. Remzibey-05 seed, and by 91, 31, 71, and 131% for cv. Dinçer seed, respectively, between the initial and final moisture content levels. The terminal velocities of the Remzibey-05 and Dinçer seeds increased by 15 and 11%, respectively, with increase in moisture content between the initial and final levels.K e y w o r d s: safflower seed, moisture content, frictional properties, aerodynamic properties

The thermal conductivity of agricultural seeds has been used as engineering parameter in the design of processes and machines for drying, storing, aeration and refrigeration. The thermal conductivity of safflower seeds was determined and its changes with moisture content, bulk density and cultivar investigated. The thermal conductivity values of cv. Remzibey-05 increased from 0.105 to 0.132 W m–1 K–1 and from 0.108 to 0.137 W m–1 K–1 for low and high (loose and dense) bulk densities, respectively, as the moisture content increased from 5.79 to 20.38% db. Likewise, the thermal conductivity values of cv. Dinçer increased from 0.106 to 0.137 W m–1 K–1 and from 0.110 to 0.140 W m–1 K–1 for low and high bulk densities, respectively in the moisture range of 5.07 to 20.30% db. The thermal conductivity values obtained with the high bulk density was higher than those obtained with the low bulk density for both cultivars. The thermal conductivity value of cv. Dinçer seeds was lower than that of cv. Remzibey-05 seeds.

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