Study On The Extraction Process Of The Two Kinds Of Vegetable Oil By Aqueous Enzymatic Method

Aqueous enzymatic method is an emerging oil extraction technique with water instead of organic solvent as dispersion phase. In this method, in order to achieve the purpose of oil extraction, the cell wall, lipid bodies and other tissues of oil plants were destroyed by enzymatic hydrolysis. In the plant cells, the grease combined in complex macromolecules lipoprotein and lipopolysaccharide were replaced by water molecule wirh use of enzymes. Then the mixture was divided into immiscible three-phase oil, water and sediment because of different densities after centrifugation. Furthermore, the microwave was used to enhance the degree of rupture and dispersion of the plant cells and improve the efficiency of enzymatic processes were discoveried.In this paper, a method for oil extraction based on enzymatic hydrolysis was established and applied to the research of two plant oils,There are the sesame oil rich in unsaturated fatty acids and the camphor oil mainly containing saturated fatty acids respectively. And the effects of microwave on the process of oil extraction and oil quality were investigated. The results show that the activity of enzymes and other active ingredients in raw materials can be passivated and the enzymolysis of cell tissue can be improved by microwave which can promote the efficiency and quality of enzymatic hydrolysis.The optimized extraction conditions for sesame oil were as follows: the solid-to-liquid ratio was 2:13 and the pH was 4.5, the time of the microwave irradiation with 400 W was 15 s. Then another fresh sesame(36 %) and papain(20 mg/g) were added. In the process of enzymatic hydrolysis, the temperature, speed and time were 55℃, 260 rpm and 3.5 h, respectively. The mixture was centrifuged at the speed of 4000 rpm., After the above process,the highest extraction rate was 80 %.The best extraction process for camphor oil was as follows: the solid-to-liquid ratio was 1:4.5; the microwave power and time were 400 W and 20 s, respectively; and the temperature of enzyme hydrolysis was 55℃.The compensation of enzyme was Xylanase(25 mg/g), Cleeulase(15 mg/g) and alcalase(2.4 L, 8 μL/g) and the time of enzymatic hydrolysis was 2.0 h. The mixture was centrifuged at the speed of 4000 rpm. And the highest extraction rate was 78%.The crude oil extracted by aqueous enzymatic method is clear, transparent with light color and fragrance, but no odor smell. The most indexes of crude oil were complied with the standard of product oil other than the high acid value and insoluble impurities. And the acid value and peroxide value rose and the iodine value declined after microwave processing, but the product quality was not affected.