Rape seeds (Brassica napus var. oleifera) that are dried in a dryer come from different places. Such seeds with various moisture levels and of different varieties get mixed while they are entering the dryer and during the process of drying. Since rape seeds vary in their moisture and morphology structures they exhibit different reactions in the drying process. Also, the speed of letting the unnecessary water out reach a hydroscopic equlibrium is different for different varieties.\nVariety Silvia has been lately explored with a great deal of attention due to its characteristes (such as high adaptability and a safe manufacture in different ecological conditions). This is "00" group of winter rape seeds which means that its oil does not contain eruca acids and consists of favourable fat acids; in addition to this, rape seed grits have only 25 mmol/g of glucosinolate.\nThis paper deals with the speed of water evaporation from variety Silvia, as well as its physical properties (angle of repose, angle of frietion, mass of 1000 seeds, test weight) in the period of three years. The time needed for drying five different varieties of rape seeds (Diana, Karola, Semu 910201, Semu 93-10 and Lirajet) was compared with the time necessary for variety Silvia.\nThe results show that under approximately equal conditions at the moisture levels of seeds the period of drying for variety Diana is the shortest, whereas it is the longest for varieties Semu 93-10. In order to compare different varieties we worked out exponential equations and polinomial regression equations with the minimum determination coefficient of 0,95.\nAt the average moisture level of 6,3 % the angle of repose was different, varying from 21,32° (Semu 91020) to 25,92° (Semu 93-10). The angle of friction also differed from 4,71° (Silvia) to 6,8° (Semu 93-10). The mass of 1000 seeds is reduced along with the reduction in seed moisture and on average it is 3,937 g at the moisture of 15,88 %, while at the moisture of 6,33% it is 3,49 g. The test weight somewhat increases with the reduction in seed moisture and is 66,83 kg at the average moisture of 15,88 % whereas at the moisture of 6,33 % it is 67,21 kg.

rape seed; variety; drying; physical properties

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia