Optimization of processing parameters for extraction of peanut protein isolate by response surface methodology

Peanut protein isolate was prepared through alkaline extraction and acid precipitation from low variability peanut meal.The optimal values of theoretical parameters including extraction temperature,ratio of liquid and material,extraction time and extraction pH were investigated by Box-Behnken surface response design method.The optimum conditions of alkaline extraction were as followed:extraction temperature 57.5℃,ratio of liquid to material 12∶1,extraction time 100min and pH 9.2.And based on the single-factor test,the optimum pH4.5 of acid precipitation was determined.Under these conditions,the maximum protein extraction rate of 87.57% was obtained.The relative error with predicted value was 0.4%.