Abstract: In this study, backward extraction procedure was explored for wheat germ protein. After recovery of isooctane and dissolution of residual solid with a small amount of KCl buffer solution, the wheat germ protein was precipitated by acetone, while AOT remained in the acetone phase. The effects of KCl concentration, pH value and the amount of buffer solution on the backward extraction rate were investigated. On the basis of single-factor tests, the optimum backward extraction conditions were achieved by response surface methodology, namely KCl concentration 0.61 mol/L, pH value 9.47 and the amount of buffer solution 1.0 ml. Under these technical conditions, the backward extraction rate of protein reaches 80.07%.

Key words: reverse micelles, wheat germ protein, backward extraction, response surface methodology