Chemical composition of expeller-extracted and cold-pressed rapeseed cake

Abstract

Chemical composition of locally produced expeller extracted and cold-pressed rapeseed cake was evaluated. Cold-pressed rapeseed cake was produced at 60 °C and the temperature during processing of expeller extracted cake varied between 98–112 °C. It was concluded that cold-pressed rapeseed cake contained less crude protein (30.6 vs. 36.1%), N-free extractives (28.2 and 30.7%, resp.) and crude fibre (11.2 and 12.4%, resp.) but more crude fat (17.8 and 11.6%, resp.) and had higher metabolizable energy content (14.5 and 14.2 MJ/kg). Higher energy content in coldpressed cake is directly related to its high oil content. There were no big differences in crude ash, calcium and phosphorus content in different cake types. Chemical composition of rapeseed cake is influenced by pressing technology and conditions that are used in particular oil plant. Pressing conditions influence the effectiveness of oil removal and thereby also the nutrient content and nutritional value of produced rapeseed cake.