Oxygen resence in food packages is mainly due to failures in the packaging process, such as mixture of gases containing oxygen residues, or inefficient vacuum.
Specifically, oxygen in foods triggers lipid oxidation, aerobic microorganism growth, enzymatic browning, and a loss of nutritional value, resulting in severe reductions in the shelf-life of oxygen-sensitive foods such as nuts, roasted coffee beans, bakery goods, oil, and meat products
Modified atmosphere packaging (MAP) is often used as an alternative to reduce the O2 inside food packaging. The presence of oxygen scavengers inside polymeric matrixes can enhance gas-barrier properties of the package and simultaneously remove residual oxygen.
Oxygen scavengers are materials that remove oxygen from the packaging through a chemical reaction. Oxygen scavengers extend shelf life of products by eliminating oxygen without being a part of the food itself, i.e., they are not food additives and they work from the outside.
An appropriate oxygen scavenger is chosen depending on the O2-level in the headspace, how much oxygen is trapped in the food initially and the amount of oxygen that will be transported from the surrounding air into the package during storage.
The most effective and generally used oxygen scavengers are oxygen-scavenging sachets containing iron powder.
However, non-metallic oxygen scavengers have also been developed to alleviate the potential for metallic taints being imparted to food products and the detection of metal by in-line detectors.
There are 2 types of commercially available oxygen scavengers. The self-reactive type is a scavenger which is equipped with moisture or other necessary triggering systems, and the other type is a scavenger that needs to be triggered by moisture prior to the oxygen scavenging reaction.
Food additive: Oxygen scavenger
