Combined Action of High Pressure, Temperature, pH and Time on Jack Bean &alpha-Mannosidase Activity

The pressure, temperature, pH and treatment time are assumed to be key factors affecting the enzyme activity, and their combined influence on &alpha-mannosidase activity Jack bean was investigated by measuring &alpha-mannosidase activity under conditions of pressure at 0-500 MPa, temperature at 35-55°C, pH at 3.5-5.5 and treatment time at 24-168 h in this study. Taguchi orthogonal experiment was designed to optimize parameters. Results indicated that the pressure is most significant factor influencing the enzyme activity and progressive losses of activity of α-mannosidase were observed with increasing hydrostatic pressures. Temperature and pH have also significant influences on enzyme activity. The optimal combinations of four parameters for Jack bean &alpha-mannosidase activity were: temperature at 50°C, pH at 5.0 and treatment time at 120 h in the absence of high pressure and temperature at 45°C, pH at 5.0 and treatment time at 48 h and hydrostatic pressure at 150 Mpa in the presence of high pressure, respectively.