Related Experiment Videos
Soybean lipoxygenase inactivation by pressure at subzero and elevated temperatures
I Indrawati1, A M Van Loey, L R Ludikhuyze
1Department of Food and Microbial Technology, Laboratory of Food Technology, Katholieke Universiteit te Leuven, Heverlee, Belgium.
Journal of Agricultural and Food Chemistry
|May 4, 2000
Summary
High pressure and temperature treatments effectively inactivate soybean lipoxygenase (LOX). Inactivation rates depend on pressure-temperature combinations, increasing with pressure and showing a minimum near 30°C.
Area of Science:
- Biochemistry
- Food Science
- Enzyme Kinetics
Background:
- Soybean lipoxygenase (LOX) is an enzyme involved in lipid oxidation.
- Understanding LOX inactivation is crucial for food processing and quality control.
- High pressure and temperature are non-thermal and thermal processing methods, respectively.
Purpose of the Study:
- To quantitatively study soybean lipoxygenase (LOX) inactivation under various pressure and temperature conditions.
- To kinetically characterize the inactivation process using rate constants, activation energies, and activation volumes.
- To model the pressure-temperature dependence of LOX inactivation.
Main Methods:
- Enzyme inactivation assays were performed at pressures up to 650 MPa and temperatures from -15 to 68°C.
- Kinetic parameters including rate constants, activation energies, and activation volumes were determined.
- A modified Hawley kinetic model was used to describe the pressure-temperature dependence.
Main Results:
- Irreversible LOX inactivation followed first-order kinetics across all tested conditions.
- Inactivation rate constants increased with increasing pressure at constant temperature.
- At constant pressure, inactivation rates exhibited a minimum around 30°C, increasing with deviations in either direction.
Conclusions:
- Soybean LOX inactivation is significantly influenced by the combined effects of pressure and temperature.
- The study provides a kinetic model for predicting LOX inactivation under diverse processing conditions.
- Findings offer valuable insights for optimizing food processing techniques to control LOX activity.