What is oxidation, and how does it alter food products?



Oxidation is a reaction that takes place when oxygen has access to products containing fat or pigments. If fats oxidize, they produce “off” odors and flavors (stale, rancid odors). Often, if fats oxidize, vitamins also oxidize and lose their activity. If pigments oxidize, they can change color completely. For example, red meat turns gray when the myoglobin pigment oxidizes. In this case, the product is not unsafe; it just looks less appealing. Wrapping some food products in a wrap that limits oxidation (such as Saran Wrap) will help to keep them fresh.
Susan Brewer, Ph.D, University of Illinois, Departm