The extraction of polyphenoloxidase (PPO) from Litopenaeus vannamei was studied at different temperatures, pH and ionic strength conditions. Optimum extracts at pH = 7.2 were treated by hiph pressure carbon dioxide (HPCD) technology at 20 MPa and in a temperature range from 35 to 50 °C. Inactivation kinetics for PPO extracts were determined and fitted to the Weibull model. The effect of HPCD on PPO activity was also evaluated in shrimps in vivo, finding that PPO could be easier inactivated than in the crude PPO extract. Color of Litopenaeus vannamei was visually followed right after HPCD treatment and thermal treatment at the same temperature and during storage at 4 °C during a week, showing good results when shrimps were treated with HPCD in the absence of water.
