Study On Squalene Extraction From Soybean Oil Deodorizer Distillate

Squalene(2,6,10,15,19,23- hexamethyl-2,6,10,14,18,22-tetracosahexaene), a highly unsaturated linear triterpenoid, is extracted in most animals and plants. Squalene can be used in many aspects such as pharmaceuticals and cosmetics because of its antitumor properties and resistance to oxidation. Squalene mainly comes from shark liver oils. However, with the low reproduction rate of shark and environment pollution of the species, sourcing squalene from animals is becoming limited. Therefore, in order to enhance the source of squalene, squalene extracted from plant oils has become a trend. Soybean oil deodorizer distillate which is a byproduct of the deodorization step of soybean oil refining is used as the raw material in this paper. This work was managed to separate and purify high purity of squalene by an integrational process of saponification, crystallization, modular distillation, the second-class crystal ization and also solvent extraction.Firstly, the composition and physicochemical properties of soybean oil deodorizer distillate were determined to understand the characteristics of soybean deodorization distillate and lay the foundation for follow-up study.Secondly, the squalene was preliminary extracted by saponification and crystallization. In the alkaline ethanol saponification step, the orthogonal design was applied to optimize the conditions and the best conditions were confirmed as follows: time of 40 min, temperature of 90°C, alkali concentration of 1.6 mol/L, material/liquid ratio of 1:2. Under these conditions: the content and yield were 10.34% and 77.59%, respectively. In the second step, the optimal crystallization temperature was 4°C, material liquid ratio was 1:6 and crystallization time was 3 h. Under these conditions, the content of 12.32% and the yield of 83.69% were obtained.Thirdly, further enrichment of squalene by molecular distillation was reasearched. The process pressure was set at 1.0 Pa, the feed temperature at 70°C, and the condenser temperature at 40°C. The suitable distillation conditions of the first-stage molecular distillation were obtained based on the single factor: distillation temperature of 110°C, the feed speed of 1.0 m L/min and the rolling film speed of 120 rpm. Under these conditions, squalene levels in the heavy stream reached 18.90% and recovery was 82.05%. In the second stage molecular distillation process, the response surface method was applied to optimize the conditions, when distillation temperature was 162°C, feed rate was 3.0 m L/min, the rolling speed finally was 82 rpm, the squalene levels in light stream were 32.54% and 70.52%, respectively.Lastly, the secondary crystallization and solvent extraction were used to purify squalene, The GC-MS and IR spectra were used to identify the squalene product’s components and structure, and the common properties of extracted squalene product was determine. In the secondary crystallization step, the optimal crystallization temperature was 0°C, material liquid ratio was 1:4 and crystallization time was 4 h. Under these conditions, the content of 41.76% and the yield of 80.11% were obtained. In the last step, the obtained best conditions were: extraction temperature of 40°C, material liquid ratio of 1:5 and extraction time of 3 times. Under these conditions, the squalene content can reach 64.28% and yield of 76.96%. Determination results proved that the purified material was squalene, and the index of squalene product meet the industrial characteristics.