Modeling of the Humidity Effects on the Oxygen Absorption by Iron-Based Scavengers
Article first published online: 6 JAN 2010
© 2010 Institute of Food Technologists®
Journal of Food Science
Volume 75, Issue 2, pages E91–E99, March 2010
How to Cite
Polyakov, . V. A. and Miltz, J. (2010), Modeling of the Humidity Effects on the Oxygen Absorption by Iron-Based Scavengers. Journal of Food Science, 75: E91–E99. doi: 10.1111/j.1750-3841.2009.01464.x
- Issue published online: 1 MAR 2010
- Article first published online: 6 JAN 2010
- MS 20090303 Submitted 4/28/2009, Accepted 10/13/2009.
- iron powder;
- oxygen absorption kinetics;
- oxygen scavengers;
- water vapor adsorption
ABSTRACT: It has been reported in the scientific literature that moisture is required for oxygen absorption by iron-based scavengers. The rate of oxygen absorption is crucial in oxygen-sensitive foods. However, no quantitative correlations between the relative humidity and the oxygen absorption by these scavengers have been found in the scientific literature. The humidity level, the O2 concentration, and the gas composition inside the package are the major factors determining the isothermal O2 absorption kinetics. In the present study, the effect of RH on the oxygen absorption of an iron powder taken from an oxygen scavenger was investigated. This process was modeled, and correlations have been developed and compared to experimental results. The developed models describe well the effect of humidity on the oxygen absorption by the iron powder. It was found that an increase in the rate of oxygen absorption results in a decrease in the porosity, an increase in the specific surface area of the iron powder's corrosion products, and a decrease in the O2 diffusivity through the particles. The heat evolved during the exothermic reaction leads to a decrease in the amount of water adsorbed on the corrosion products. The results of the present study elucidate the effect of moisture on the O2 absorption by iron-based oxygen scavengers and can be used for a proper design of packages intended for storage of foods and fruits and vegetables of intermediate and high water activity.
Practical Application: Since humidity has an important role in determining the rate of oxygen absorption kinetics by iron-based oxygen scavengers, using the models derived and presented in the present publication can bring upon a better understanding of the oxygen absorption process and a more efficient way of using oxygen scavengers in the packaging and storing of different oxygen sensitive foods.