ULTRASONIC-ASSISTED HYDRATION DEGUMMING PROCESS OF RICE BRAN OIL

Rice bran oil is a kind of vegetable oil with higher nutritional value.The unsaturated fatty acid content of rice bran oil is more than 80%.Meanwhile,it is rich in many trace components such as oryzanol,sterols,and vitamin E.Degumming is one of the most important steps for refining and processing of rice bran oil.In this study,the influence of ultrasonic-assisted technology on the hydration degumming efficiency of rice bran oil was studied,with phospholipid contentand degumming rate asevaluation indicators.Through single-factor experiments,the effects of ultrasonic time,ultrasonic power,degumming temperature and water addition on the degumming effect were investigated.On the basis of single-factor tests,the four-factor three-level orthogonal test was used to optimize the ultrasonic-assisted hydration degumming process of rice bran oil.The results showed that all of ultrasonic time,ultrasonic power,degumming temperature and water addition had significant effects (P<0.5) on phospholipids content in rice bran oil and the degumming rate.Within the scope of the experimental investigation,shorter ultrasonic time (1-2 min) and lower ultrasonic power (100-200 W) could not only improve the degumming efficiency of rice bran oil but also prevent the occurrence of emulsification effectively.Orthogonal experiments showed that the order of factors affecting the degumming effect was:degumming temperature>ultrasonic time>ultrasonic power>water addition.The optimal conditions of ultrasound-assisted hydration degumming process of rice bran oil were:ultrasonic power 200 W,degumming temperature 45℃,the amount of water 5% and ultrasonic time 2 min,under which the phospholipid content of degummed rice bran oil was 1.44 mg/g,and the degumming rate was 85%.Compared with traditional hydration degumming methods,ultrasound-assisted hydration degumming technology has the advantages of high degumming efficiency and short processing time.The present study will supply guidance for the refining of rice bran oil.