Heat Inactivation Kinetics of Apple Polyphenoloxidase and Activation of its Latent Form
Article first published online: 20 JUL 2006
Journal of Food Science
Volume 62, Issue 3, pages 508–510, May 1997
How to Cite
YEMENICIOĞLU, A., ÖZKAN, M. and CEMEROĞLU, B. (1997), Heat Inactivation Kinetics of Apple Polyphenoloxidase and Activation of its Latent Form. Journal of Food Science, 62: 508–510. doi: 10.1111/j.1365-2621.1997.tb04417.x
- Issue published online: 20 JUL 2006
- Article first published online: 20 JUL 2006
- Ms received 7/15/96; revised 12/5/96; accepted 12/29/96.
- latent PPO;
- heat activation;
- heat inactivation
Heat inactivation kinetics of crude polyphenoloxidase (PPO) from six apple cultivars (Golden Delicious, Starking Delicious, Granny Smith; Gloster, Starcrimson and Amasya) were studied at three temperatures (68°, 73° and 78°C). PPO activity initially increased and then decreased with heat, following a first order kinetic model. Increase in activity indicated presence of latent PPO. Regression coefficients for the linear portions of inactivation curves were computed to determine inactivation parameters. Reaction data at 78°C revealed that PPO in Amasya was the least and Starking Delicious the most heat-stable. Rate constants for heat inactivation at 78°C ranged from 15.99–28.27. 10−2 min−1. Activation energies varied between 54.7–77.2 kcal. mol−1 with z values of 7.1–10.0C°.PPO in apples was generally more heat-stable than PPO in most fruits.