Optimization of supercritical fluid extraction of daidzein from soybean after extrusion

Abstract

A set of optimal conditions for supercritical fluid extraction (SFE) of daidzein in soybean previously subjected to extrusion at the rotate speed of screw 4.5×g and the temperature of 80℃ was developed. The quadratic orthogonal rotation design with five factors (extracting temperature, extracting time, ethanlol content, cosolvent quantity and flow rate) was used and a mathematical model was developed based the experimental results. Optimal conditions were verified and compared with control experiments conducted in parallel. The results from SFE showed that all five experiment factors had significant effects on the yield of daidzein. The mathematical model agreed well with the experimental results. It was found that there were 27 optimal extract conditions under which daidzein yield was higher than 0.092%. The optimal extracting conditions were stable and reproducible. Results from the control experiments showed that extrusion could significantly enhance the extraction of daidzein. The extraction of daidzein from extruded soybean and its products with supercritical CO2 is a potential technique for practical applications in the future.
Key words: extraction, daidzein, supercritical, extrusion, cosolvent, mathematical model
DOI: 10.3965/j.issn.1934-6344.2009.02.057-064

Citation: Zhou Quancheng, Li Lei, Shen Dechao. Optimization of supercritical fluid extraction of daidzein from soybean after extrusion. Int J Agric & Biol Eng. 2009; 2(2): 57－64.