The Effect of Electric Field on Important Food-processing Enzymes: Comparison of Inactivation Kinetics under Conventional and Ohmic Heating
نویسندگان
چکیده
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 (conventional and ohmically processed) was made equal to determine if there was an additional inactivation caused by the presence of an electric field, thus eliminating temperature as a variable. All the enzymes followed 1st-order inactivation kinetics for both conventional and ohmic heating treatments. The presence of an electric field does not cause an enhanced inactivation to alkaline phosphatase, pectinase, and galactosidase. However, lipoxygenase and polyphenoloxidase kinetics were significantly affected by the electric field, reducing the time needed for inactivation. The results of the present work can be used industrially to determine processing effectiveness when ohmic heating technology is applied.
منابع مشابه
Ohmic 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...
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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 ...
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