There are two general methods of rapeseed oil extraction, pressing and solvent extraction. We will introduce the characteristics of each from the following aspects:
1.Process Principle
Pressing method: A physical method is used to extract the oil from rapeseed by squeezing. This method does not involve chemical solvents and therefore retains the original flavour and nutrients of the oil.
Solvent extraction: A chemical method is used to extract the oil from the rapeseed by means of a solvent (e.g. hexane). The solvent is then separated through a series of processes to obtain canola oil.
2.Nutritional value
The pressing method better retains the nutrients in rapeseed, such as vitamin E and sterols, because it does not involve chemical solvents. The solvent extraction method, on the other hand, loses some of the nutrients during processing. Therefore, in terms of nutritional value, the pressing method is more advantageous.
3.the flavour and taste
As the pressing method does not use chemical solvents, the oil has a more pure flavour and taste, with a unique rapeseed oil aroma. On the other hand, solvent extraction may leave a slight chemical solvent flavour in the oil, which affects the taste. Therefore, the pressing method is also more advantageous in terms of flavour and texture.
4.the production cost
The solvent extraction method uses chemical solvents, so it needs some necessary supporting equipment, such as pre-treatment work, we need to use some equipment to treat the rapeseed into a more suitable state. After solvent extraction, we will get a mixture of oil and solvent, and meal and solvent mixture, so we need to separate the solvents in the oil, and also need to separate the solvents in the meal, which are necessary equipment. So the solvent extraction method needs a whole set of professional equipment, so the investment is higher, more suitable for the oil and grease project with large processing capacity.
Pressing method is more flexible, rapeseed can be pressed after simple steaming and stir-frying, and the crude oil after pressing only needs to be filtered, the crude oil is of high quality, and the subsequent refining process will be smoother. However, the output of oil press is very limited, if the production of large projects need to be equipped with a number of units, the efficiency of oil production is not as good as solvent extraction. So the press is more suitable for small output, and the input cost will only be bigger in case of large output.
Some customers need large production projects, not only to consider the cost of oil and grease, but also consider the quality of oil and grease, so in this case we will recommend him to do pre-pressing first, pre-pressing machine production is relatively large, but the residual oil in the meal is high, we can firstly get the high quality of the physical press oil, and then the rest of the cake and meal for the solvent extraction to get the oil.
To sum up, according to the actual production requirements, to determine the appropriate process parameters, you can contact us at any time, Siwei will be free for you to issue a professional project solution for you to choose.
