Separation of red bean protein by reversed micellar extraction

Extraction and separation of red bean protein was investigated with reversed micellar extraction by using Plackett Burman (PB) design, steepest ascent design and response surface methodology.Firstly, PB design was applied to identify CTAB concentration, pH in aqueous phase and extraction time as the most significant of 7 factors influencing the forward extraction rate.Then the center points of the three factors were determined based on steepest ascent design.Finally, the optimization of the three factors was carried out by using Box-Benhnken design.The results showed that the forward extraction conditions were as follows: pH 4.3, NaCl concentration 0.02mol /L, CTAB concentration 40.24mmol /L, protein concentration 2mg /mL, extraction time 90min, temperature 20℃, alkyl alcohol than 4 ∶ 1.Red bean protein extraction rate was 56.85%.Under this condition, the backward extraction yield was 64.96% by pH 6.0, 1.1mol /L NaCl solution, temperature 20℃ with as backwards extraction condition.