Effects of compressed carbon dioxide treatment on the specificity of oxidase enzymatic complexes from mate tea leaves

This work evaluates the enzymatic activity of peroxidase (POD) and polyphenoloxidase (PPO) present in the crude extract of mate tea leaves (Ilex paraguariensis St. Hill) submitted to compressed CO2. The effects of temperature, exposure time, solvent reduced density, pressure, and depressurization rate on the activity of peroxidase and polyphenoloxidase were evaluated through a fractionated factorial experimental planning. Results show that temperature of 30 °C, pressure of 70.5 bar, exposure time of 1 h, depressurization rate of 10 kg m−3 min−1 and carbon dioxide reduced density of 0.60 led to an enhancement of around 25% in the peroxidase activity and a polyphenoloxidase activity loss of 50%. Using this experimental condition, thermal stability at low temperature (−4 °C) and the influence of successive pressurization/depressurization cycles were determined. Results suggest that it is possible to increase the specificity of the enzymatic extract towards enhancing POD or PPO activity depending on the experimental condition employed, and that the processing of enzymatic complexes with compressed CO2 may be a promising route to increase the specificity of enzymatic extracts.