Inactivation kinetics of food enzymes during ohmic heating
نویسندگان
چکیده
0308-8146/$ see front matter 2010 Elsevier Ltd. A doi:10.1016/j.foodchem.2010.04.047 * Corresponding author. Tel.: +421 2 59325254; fax E-mail address: [email protected] (M. Pola Ohmic heating of milk and fruit and vegetable juices was carried out at several incubation temperatures to investigate inactivation of alkaline phosphatase, pectin methylesterase and peroxidase. Mechanisms of inactivation of these enzymes and corresponding kinetic models were verified for each food material, using the multitemperature evaluation of inactivation data. Compared to inactivation by conventional indirect heating, kinetic parameters were changed but inactivation mechanisms remained the same. The kinetic parameter changes were relatively minor for pectin methylesterase and alkaline phosphatase. A significant destabilization of the labile isozyme fraction of peroxidase occurred by the effect of ohmic heating when the greatest decrease of stability was obtained for carrot juice. 2010 Elsevier Ltd. All rights reserved.
منابع مشابه
The Effect of Electric Field on Important Food-processing Enzymes: Comparison of Inactivation Kinetics under Conventional and Ohmic Heating
This work deals with the determination of the inactivation kinetics of several enzymes, most of them used as time-temperature integrators in the food industry. The tested enzymes were polyphenoloxidase, lipoxygenase, pectinase, alkaline phosphatase, and -galactosidase, and the inactivation assays were performed under conventional and ohmic heating conditions. The thermal history of the samples ...
متن کاملSlovak Society of Chemical Engineering Institute of Chemical and Environmental Engineering Slovak University of Technology in Bratislava PROCEEDINGS
In recent years, the world’s food industry has focused increasing attention on electrical techniques of food processing. Ohmic heating is one of these techniques that can be considered as a high temperature short time and a purely bulk heating method, having potential applications in processes such as blanching, evaporation and pasteurization in the food industry. However such technology would ...
متن کاملMathematical Model of Solid Food Pasteurization by Ohmic Heating: Influence of Process Parameters
Pasteurization of a solid food undergoing ohmic heating has been analysed by means of a mathematical model, involving the simultaneous solution of Laplace's equation, which describes the distribution of electrical potential within a food, the heat transfer equation, using a source term involving the displacement of electrical potential, the kinetics of inactivation of microorganisms likely to b...
متن کاملOhmic and moderate electric field processing: developments and new applications
Ohmic heating has been attempted at various times during the history of food processing, and finally appears to be finding its niche in a range of applications (both food and non-food). Recent developments in electrode materials and solid-state power supply technology to minimize electrolytic effects and reduce cost have made the technology commercially attractive. The number of commercial supp...
متن کاملOhmic Heating of Aloe vera Gel: Electrical Conductivity and Energy Efficiency
Ohmic heating is defined as a process which alternating electric current is passed through food with the primary purpose of heating it due to the electrical resistance and can be specially applied as an alternative heating method. In this research, Aloe vera gel concentrates having 0.5-2% soluble solids were ohmically heated up to 60°C by using four different voltage gradi...
متن کامل