| The two steps alkali refining process of crude rice bran oil with high acid value was carried out. With yield of alkali refining, bleaching rate, loss rates of oryzanol and sterol as indexes,the influence of mass fraction of lye on alkali refining effects of the first step and the second step alkali refinings was investigated and compared with the one step alkali refining process. The results showed that with mass fraction of lye increasing,the yields of alkali refining of the first step and the second step alkali refinings changed little in the two steps alkali refining process, and the bleaching rate of the first step alkali refining reached the highest when the mass fraction of lye was 14.24%,while it presented fluctuation in the second step alkali refining; low mass fraction of lye was beneficial to the retention of oryzanol and sterol in the second step alkali refining of the two steps alkali refining process；comparing with one step alkali refining process, the yield of alkali refining increased by 4.89 percentage point on average and the loss rate of oryzanol decreased by 5.87 percentage point on average in the two steps alkali refining process under the condition of the same mass fraction of lye; the bleaching rate improved by 9.25 percentage point on average and the loss rate of sterol reduced by 12.64 percentage point on average when mass fraction of lye （8.07%-14.24%）was low. In short, for crude rice bran oil with high acid value, two steps alkali refining had obvious advantages in increasing the yield of alkali refining and bleaching rate and decreasing the losses of oryzanol and sterol when mass fraction of lye was below 14.24%. |
