Supercritical carbon dioxide is commonly known as a green alternative for hexane when it comes to the extraction of oils and fats. The polarity of supercritical carbon dioxide can be influenced by adjusting the pressure and/or temperature at which the extraction takes place. This allows fractionation to take place during the extraction.
During the presentation at the 20th Euro Fed Lipid Congress and Expo, the following topics will be addressed:
– extraction of oils/fats by means of supercritical carbon dioxide;
– fractionation of oils/fats by means of supercritical carbon dioxide;
– simultaneous extraction and fractionation by means of carbon dioxide.
Experiments were performed on different types of oils/fats, e.g. shea butter, palm oil, flaxseed oil, wax moth oil and pinkies fat. It can be seen that two types of fractionation are obtained. On one hand, fraction can be observed at the level of the glycerides, i.e. separation between free fatty acids, monoglycerides, diglycerides and triglycerides. On the other hand, fraction can be observed at the level of the fatty acids, i.e. fractionation between shorter and longer fatty acids and between saturated and unsaturated fatty acids. It is also observed that fractionation is only possible for oils/fats bearing a certain glyceride profile or a certain fatty acid profile. E.g. if there is only a limited amount of free fatty acids present in the oil, it is not possible to separate them from the rest of the oil. The same goes for oils with a limited degree of saturation, in that case, it is not possible to separate the saturated fatty acids from the unsaturated ones.