Impact of supercritical carbon dioxide and high pressure on lipoxygenase and peroxidase activity

The effects of supercritical carbon dioxide (ScCO2) treatment and high hydr ostatic pressure treatment on the activities of lipoxygenase (LOX) and pero xidase (POD) were studied. Hydrostatic pressure treatment (240 MPa, 55 degr eesC, 15 min) of LOX and POD in 30% sucrose solutions without buffer led to approximately 80% and approximately 50% residual activity, respectively. A pplication of ScCO2 (35.2 MPa, 40 degreesC, 15 min for LOX and 62.1 MPa, 55 degreesC, 15 min for POD) achieved approximately 35% LOX and approximately 65% POD inactivity in 30 % sucrose solutions. Total inactivation of LOX (1 0.3 MPa, 50 degreesC and 15 min) and of POD (62.1 MPa, 55 degreesC and 15 m in) could be achieved through ScCO2 treatment of unbuffered solution. Incre asing the concentration of sucrose and buffering (pH range 4 to 9) of enzym e solutions resulted in increased resistance of the enzymes to ScCO2 treatm ent.