An economic evaluation based on an experimental study of the vitamin E concentration present in deodorizer distillate of soybean oil using supercritical CO 2

Abstract

Soybean oil is the most consumed oil in the world, representing 54% of the consumption in the worldwide market. The high production of soybean oil produces high quantities of a by-product known as deodorizer distillate or soybean sludge. This by-product is produced during the refining steps that consist of deodorization, bleaching, and refining. The soybean sludge is composed of high aggregated compounds, such as tocopherols (vitamin E), sterols (campesterol, β-sitosterol), squalene, and fatty acids. The tocopherols are concentrated in the deodorizer distillate from 11 to 13%. They are used as antioxidants and as additives in the food industry. The sterols, present in the deodorizer distillate in lower concentration, are a very important raw material in the production of hormones and in the preparation of vitamins. The squalene is a hydrocarbon mostly used in cosmetic preparations and in the biosynthesis of cholesterol. The fatty acids, making up 70% of the soybean sludge, have low quality because of the processing steps and have limited uses that do not involve food in spite of high costs. Therefore, the motivation of this work is to concentrate the vitamin E, adding value to the raw material, and concentrating other compounds of industrial interest. To concentrate vitamin E, the soybean sludge, kindly supplied by CEVAL S.A., is applied to the extractor and submitted to the operational conditions of 40, 60 and 80 °C at 90 and 170 bar. The sampling, during the extraction, is done with a micrometric valve, where the raffinate is separated from the solvent and recovered. The tocopherols are concentrated in the extractor and the fatty acids are extracted during the extraction process. The tocopherols are concentrated to at least 40% from a natural source. A better efficiency of the process was obtained at lower conditions of temperature and pressure. From the experimental data, an economic evaluation of an industrial process to concentrate tocopherol was studied and it was concluded that this process is technically and economically viable.