The enzymatic extract was prepared using the pulp and the peel of the apples from Fuji and Gala cultivar using sodium phosphate buffer 100 mM, pH 5.0 as the extraction solution. The protein concentration was determined and the Fuji cultivar showed higher amounts of protein than the Gala cultivar. The thermal treatments were carried out in the temperatures of 60, 65, 70 and 75°C for periods that varied from 1 to 10 minutes. A decrease in the activities of POD and PPO with the increase of the temperature and time was observed; however POD was not inactived following any of the treatments used. PPO was totally inativated after 10 minutes of treatment for 75°C. The electrophoresis showed a different pattern for the anionic and cationic peroxidase isoenzymes.
peroxidase; polyphenoloxidase; thermostability; apple; Mallus comunis
