Effect of Sunflower Seed Drying on Some Quality Parameters of the Seed and Oil

Drying temperature and time effect on oil quality parameters of both seed and kernel from a sunflower hybrid of potential high oil content was evaluated. Drying tests were carried through two treatments of thin layer drying, consisting the first in getting the equilibrium moisture content and the second a safe storage moisture value, both in a range of temperatures from 25 °C to 90 °C. Prolonged treatments at high temperatures affected neither the seed and kernel oil contents nor its refractive index and fatty acid composition of the oil. The grain morphology was not significantly modified and effects or craking caused by the thermal stress were not detected. Kernel oil showed lower level of free fatty acids for all treatments and temperatures but higher oxidative deterioration caused by temperature, presenting higher Totox index values than seed oil. This preliminar results would be indicating the seed phericarp influence on the drying process presenting differences in the oil qualities depending on the handling of temperature and time drying parameters.