Influence of Fluidization on Canola Drying Time and Oil Quality Parameters



Canola is known as an important oilseeds crop throughout the world. Cultivation and subsequent oil extraction of this crop has gained substatantial development in recent years in Iran. Many parts of Iran (northern provinces) especially Golestan and Mazandarn are of high relative humidity during harvesting season as well as during storage periods. Spoilage and rancidity are problems more encountered in these regions. Decreasing grain moisture content to a safe level causes increased safe storage time as well as preserved quality. It would be highly beneficial for canola producer and processor in high relative humidity localities to use new methods of drying. In this research, fluidized vs fixed bed conditions were employed for canola drying at eight experimental temperatures of 30, 40, 50, 60, 70, 80, 90 and 100 °C using a Lab. scale fluidized bed dryer. Effects of temperature and bed condition were investigated on the drying time and drying rate parameters. A Completely Randomized Design (CRD) as the experimental procedure was employed with three replications. Results indicated that using fluidized bed technique increased the drying rate while decreasing the time needed for drying, this effect being more pronounced in temperatures of less than 50 °C. For an instance, fluidizing of canola grains during the drying process caused energy savings while decreasing the drying time by approximately 32% at a temperature of 30°C as compared with fixed bed drying. This effect was less for high temperatures and was calculated approximately 27.8 % at 70-100°C. By increasing temperature, percentage of oil extraction of dried grains significantly increased while peroxide values of extracted oil remaining unchanged. Fluidizing favorably affected such quality factors as free fatty acids and color