Abstract:

Supercritical carbon dioxide extraction was applied to degrease rice bran in the present study. The process conditions for the degreasing of rice bran was optimized by response surface methodology. The effects of extraction temperature, extraction time and extraction pressure on lipid removal rate were explored with Box-Benhnken experimental design coupled with response surface analysis on the basis of single factor experiments. The optimal extraction parameters were determined as follows: extraction temperature, 46 ℃; extraction time, 94 min; and extraction pressure, 27 MPa. A lipid removal rate of 18.34% (g/100g rice bran, or 92.19% degreasing efficiency) under these optimal extraction conditions, which was close to the theoretical value. Therefore, the developed mathematical model was reliable in predicting lipid removal rate. The analysis of variance exhibited that the importance of the above three factors affecting lipid removal rate from strong to the weak were extraction pressure, extraction temperature and extraction time.

Key words: rice bran, supercritical fluid, degreasing rate, response surface methodology