Industrial Crops and Products 30 (2009) 131–136 Contents lists available at ScienceDirect Industrial Crops and Products journal homepage: www.elsevier.com/locate/indcrop Comparison of some engineering properties of rapeseed cultivars Halil Unal a,∗ , Mehmet Sincik b , Nazmi Izli a a Department of Agricultural Machinery, Faculty of Agriculture, University of Uludag, Bursa, 16059, Turkey b Department of Field Science, Faculty of Agriculture, University of Uludag, Bursa, 16059, Turkey article info Article history: Received 6 August 2008 Received in revised form 16 February 2009 Accepted 21 February 2009 Keywords: Rapeseed Brassica napus ssp. Oleifera L. Cultivar Engineering properties abstract Several engineering properties of three rapeseed cultivars (Capitol, Jetneuf and Samurai), newly planted cultivars in Turkey, were determined and compared. These properties are necessary for the design of equipments for harvesting, processing, transporting, sorting, separating and packing. Some engineering characteristics such as: average length, diameter, the geometric mean diameter, surface area, sphericity, volume, 1000-seed weight, bulk and true densities, porosity, terminal velocity, angle of repose, coefficient of static friction and rupture strength were studied. Further, multi-linear models for three cultivars were developed and presented to predict the seed surface area. Results showed that Capitol cultivar had highest length and diameter than the Jetneuf and Samurai cultivars. Capitol was significantly heavier than the others. Similarly, it was found highest the bulk density, terminal velocity, angle of repose for Capitol. But, Jetneuf cultivar had the highest true density and porosity than the Capitol and Samurai cultivars. On the six different surfaces, the coefficient of static friction of the Capitol cultivar, was significantly greater than that of the other cultivars. For all cultivars, the static coefficient of friction was greatest against rubber and the least for stainless-steel. The rupture force applied for Capitol was the highest and it was followed by the one applied for Jetneuf and Samurai. All the properties of cultivars provide useful data to engineers in equipment design and post-harvest technology for the seeds were generally found to be statistically different. These differences could be due to the individual characteristics of cultivars. © 2009 Elsevier B.V. All rights reserved. 1. Introduction There are over 350 species oil-producing plants and thousands of sub-species. Rapeseed (Brassica napus L.) is one of the world’s major sources of edible vegetable oil. Unlike soybeans, peanuts, and most other oilseeds, rapeseed comes from several species belonging to the mustard family (Cruciferae or Brassicaceae) (Donald and Bassin, 1991). Leading producers include the European Union, Canada, the United States, Australia, China and India (Anon., 2007). World pro- duction is growing rapidly, with FAO reporting that 48.97 million tonnes of rapeseed was produced. Turkey has about 6000 ha of rapeseed harvesting area, 12,615 tonnes of rapeseed production per annum (FAOSTAT, 2006). Rapeseed often is used as a general term to describe different species that are quite close in appearance but sometimes very different in their chemical composition or botani- cal origin (Donald and Bassin, 1991). The common names used for the different species depend on the country. Rapeseed also known as rape, oilseed rape, rapa, rapaseed and canola. Rapeseed contains four major constituents: oil, water, protein, and fiber. Some of the important, minor constituents are free fatty acids, phosphatides (gum), enzymes (particularly myrosinase), and ∗ Corresponding author. Tel.: +90 224 2941607; fax: +90 224 4429149. E-mail address: hunal@uludag.edu.tr (H. Unal). glucosinolates (Hougen and Stefansson, 1983). Erucic acid content is important to oil quality and for industrial use, whereas glucosi- nolate content is important for feeding quality of meal. Because rapeseeds are rich in oil, recleaning for their recovery may be justified (Röbbelen et al., 1989). Hulls (fibrous seed coats) of both sunflower and soybean are easily stripped mechanically. This is not the case for rapeseed. Industry has not yet installed equipment that efficiently removes the rapeseed hull. This will be a limiting factor for the use of rapeseed meal in animal rations (Donald and Bassin, 1991). In the process of extracting the rapeseed oil and its derivatives, the seeds undergo a series of unit operations. Knowledge of the physical properties and dependence on the cultivar of rapeseed is essential to facilitate and improve the design of the equip- ment for harvesting, processing and storage of the seeds. Various types of cleaning, grading, separation, oil extraction equipment are designed on the basis of the physical properties of seeds. Review of the literature has revealed that limited research has been conducted on the physical properties of rapeseed. Jayas et al. (1989), Ikebudu et al. (2000) and C ¸ alıs ¸ ır et al. (2005) found out some physical properties of rapeseed at a particular moisture content. However, detailed measurements of the principal dimensions and the vari- ation of physical properties of rapeseed at different cultivars have not been investigated. Furthermore, inspite of the growing impor- tance of rapeseed, much of the use of rapeseed in Turkey is limited 0926-6690/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.indcrop.2009.02.011