Cloudy oil
Vegetable oil is referred to as lees or crude oil in the form in which it is available immediately after the oil has been pressed without any further processing or purification step. It is a two-phase mixture of oil as the liquid phase and particles as the solid phase. In addition, oil ( input oil ) before going through a cleaning step (for example safety filtration as the last cleaning stage) is also referred to as trub oil , even if it has already gone through a cleaning process.
Cloudy oil contains solid impurities and, especially after long storage, so-called clouding substances , especially in edible oils. These can be glycerides , waxes or subsequently excreted amounts of mucus. After long storage, these settle on the floor and usually form a whitish coating there.
processing
After the oilseeds have been cleaned and dried by rolling or peeling, they are either pressed into lees or press cakes . The trub oil is further sedimented , filtered or centrifuged in order to separate the solid from the liquid substances. The process is also called cold pressing and is mainly used in decentralized oil mills . This eliminates the step of prior refining of the crude oils, which is common in hot pressing.
See also
literature
- E. Remmele, B. Widmann, J. Breun, A. Rocktäschel: Purification of cold-pressed vegetable oils from decentralized plants. “Gelbes Heft” No. 75, Bavarian State Ministry for Agriculture and Forests (Ed.), Munich 2002, online (PDF; 2.8 MB) ( Memento from August 13, 2007 in the Internet Archive ).
Individual evidence
- ↑ H. Liu, CG Biliaderis, R. Przybylski, NAM Eskin: Physical behavior and composition of low- and high-melting fractions of sediment in canola oil. In: Food Chemistry . Vol. 53, 1995, pp. 35-41, doi : 10.1016 / 0308-8146 (95) 95783-3 .