乙醇萃取米糠油脱酸脱蜡工艺研究

Study on Technical Process of Deacidifying and Dewaxing Rice Bran Oil through Ethanol Extraction

为探索高酸值米糠油的脱酸、脱蜡方法,以食用乙醇为萃取剂,对米糠油采用萃取的方法达到脱酸、脱蜡的目的。研究表明其优化工艺是:用95%的乙醇与米糠毛油按2.5∶1体积质量比、连续萃取2次,结果是:米糠油得率为87.59%,产品的酸值为1.21 mgKOH/g,谷维素保留率为87.10%,得到米糠毛油重8.93%的游离脂肪酸和3.48%的蜡,乙醇回收率为90.05%,溶耗酸值比为0.56。用乙醇萃取米糠油脱酸脱蜡工艺相比化学脱酸和物理脱酸工艺,设备投资少,谷维素保留率高,米糠油得率较高,回收了副产品游离脂肪酸和蜡。不足之处是消耗的乙醇较多,产品的酸值达不到一级油标准。

In order to search the process of deacidifying and dewaxing rice bran oil with high acid value, this study uses edible ethanol as extractant and extracts the rice bran oil to deacidify and dewax it. The study shows the optimized process is to extract crude rice bran oil with 95% ethanol consecutively twice according to the proportion of 2.5：1 （V/W）. The result shows that rice bran oil output ratio is 87.59% ,the acid value of the oil is 1.21 mg KOH/g, oryzanol retention rate is 87.10% ,the weight of recycled free fatty acid is 8.93% of the weight of rice bran oil,the weight of wax is 3.48% of the weight of rice bran oil ,the recycling rate of ethanol is 90.05%, and the ratio of oil loss and acid value is 0.56. Compared with chemical deacidifying and physical deacidifying process, the abovementioned process of deacidifying and dewaxing rice bran oil through ethanol extraction needs less equipment investment, realizes higher oryzanol retention rate and higher oil output ratio, and reclaims free fatty acid and wax as by - products. Its shortcomings are high ethanol consumption and the acid value of product can not reach the standard of the first grade oil.