Polyphenoloxidase deactivation kinetics during ohmic heating of grape juice
| dc.contributor.author | Içier, F | |
| dc.contributor.author | Yildiz, H | |
| dc.contributor.author | Baysal, T | |
| dc.date.accessioned | 2025-04-10T10:32:46Z | |
| dc.date.available | 2025-04-10T10:32:46Z | |
| dc.description.abstract | The heating method affects the temperature distribution inside a food, and directly modifies the time-temperature relationship for enzyme deactivation. Fresh grape juice was ohmically heated at different voltage gradients (20, 30, and 40 V/cm) from 20 degrees C to temperatures of 60, 70, 80 or 90 degrees C and the change in the activity of polyphenoloxidase enzyme (PPO) was measured. The critical deactivation temperatures were found to be 60 degrees C or lower for 40 V/cm, and 70 degrees C for 20 and 30 V/cm. Various kinetic models for the deactivation of PPO by ohmic heating at 30 V/cm were fitted to the experimental data. The simplest kinetic model involving one step first-order deactivation was better than more complex models. The activation energy of the PPO deactivation for the temperature range of 70-90 degrees C was found to be 83.5 kJ/mol. (c) 2007 Elsevier Ltd. All rights reserved. | |
| dc.identifier.e-issn | 1873-5770 | |
| dc.identifier.issn | 0260-8774 | |
| dc.identifier.uri | http://hdl.handle.net/20.500.14701/39131 | |
| dc.language.iso | English | |
| dc.title | Polyphenoloxidase deactivation kinetics during ohmic heating of grape juice | |
| dc.type | Article |