Optimization of protein extraction from Chuanminshen violaceum based on response surface methodology

The extraction condition of protein from Chuanminshen violaceum by ultrasonic extraction was optimized by single factor experiments and response surface methodology. The results showed that all investigated parameters had a notable effect on the extraction yield of protein and could be ranked in decreasing order of importance in their effects as follows : extraction temperature, solid- liquid ratio, ultrasonic action time and ultrasonic power. The optimum conditions for extracting protein from Chuanminshen violaceum were determined as follows:p H12.5, liquid-solid ratio (m L/g) 24∶1, ultrasonic power 185 W, extraction temperature 34℃, ultrasonic action time 31 min. Under this condition, the average rate of extraction of polysaccharides was 54.62%. The established regression model describing the extraction yield of protein as a function of four extraction parameters was highly significant (R2=0.9484) . The predictive and experimental results were found to be in good agreement. Thus, the model was applicable for the prediction of protein yield.