Recovery of the high aggregated compounds present in the deodorizer distillate of the vegetable oils using supercritical fluids

Nowadays, vitamins and sterols are produced synthetically, so the interest in the extraction of these compounds from natural sources is increasing. The aim of this work is to develop a supercritical fluid process to concentrate the vitamin E (tocopherol) presents in the by-product of the refining process of different vegetable oils, like corn, sunflower, canola and soybean, known as the deodorizer distillate (DD). This by-product is rich in high aggregated value compounds like sterols, tocopherols, squalene and fatty acids. The simulation of the vitamin E concentration from the deodorizer distillate using supercritical carbon dioxide was done in a semi-batch mode using operational conditions varying from 40 to 80 °C for temperature and from 90 to 350 bar for pressure, using the Rachford-Rice procedure. Tocopherol, squalene, linoleic acid and stigmasterol were chosen the key-components to represent the raw material. Different operational conditions were necessary to separate the main components present in the deodorizer distillate, and it indicates the necessity of a process with extractors in series to raise the separation in steps. The temperature, 40 °C, is the better one to promote the effective separation between all the components involved, but different conditions of pressure is necessary to separate the linoleic acid (90 bar), stigmasterol (250 bar) and squalene (350 bar) from tocopherol. The separation between stigmasterol and squalene is the more difficult among the others.