Rapeseed oil – oil pressed or extracted from rapeseed (lat. Brassica napus L.).
Rape is the most important and most productive oil plant in Europe
At yields of 3-5 tonnes / ha and 40% of the oilseed rape seed oil, from 1 hectare can produce about 1,600 liters of oil.
Two methods of production of rapeseed oil: cold pressing, which can be done in private and centralized industrial stamping.
Decentralized production (cold pressing)
In the process of cold pressing, there are two basic steps – stamping cleaned grains and oil filter.
Grain moisture should not exceed 7-8%. Punching takes place at grain 15 – 25 ° C, mainly in screw presses. The efficiency of this process is 75-85%. In the next step cloudy oil (solids content 0.5-6%) is treated by settling and filtration or centrifugation. Oil-cake can be used as a protein supplement for animal feed.
Industrial production (heat-pressing)
In the first step oilseed grains are cleaned and if necessary dried, ground and heat treated with steam to improve the efficiency of the pressing process. As a result, the initial discharge by means of screw presses are obtained most of the oil contained in the grain. Makuch received after the discharge still contains about 10-25% oil. The next step is subjected to a chemical treatment using hexane and light gasoline at 80 ° C. This allows for the extraction of more than 98% of the oil contained in the grain. The resulting oil is filtered and purified by distillation from hexane.
Due to thermal and chemical extraction oil contains some undesirable by-products, therefore it must be refining.
The following processes are used: degumming (related to the period of storage and use), deacidification (removal of free fatty acids), bleaching (removal of pigments) and deodorisation (removal of essential oils and flavors). The purified oil is referred to as refined. It has many uses, including as a fuel for modified engines, respectively.
As used in the production of methyl esters of higher fatty acids is also suitable for lubrication of feed and the use of the further process of production of edible oils and margarines.