Traditionally, oxygen-sensitive foods and beverages have been packaged in such a way as to minimize their exposure to oxygen . This oxygen may be in the package at the time of sealing, or may enter the pace by permeation or leakage over the storage life. The first source of oxygen has frequently been addressed by the use of evacuation and inert-gas flushing, while the ingress has been minimized by optimal sealing and the use of high- barrier packaging materials .The approaches used to solve both oxygen problems are now recognized as providing only partial solutions, leaving options for improvements in food quality, production and distribution economics, reduction in environmental impacts, and increased convenience of use.
The impact of oxygen on food quality, and ultimately shelf life, is dependent not only upon the quantity of oxygen available for chemical oxidation or support of growth of organisms but also upon the rate of the reaction which consume the oxygen. This in turn, will be influenced by solubility of the gas in the medium provided by the food or beverage. The oxidation of far in, for example, potato crisps has been shown to be highly dependent upon water activity, with a minimum rate at a_w 0.3-0.4, and the increase in reaction rate above this value is interpreted in terms of the formation of an aqueous multilayer on the food with consequent dissolution of oxygen and enhancement of the oxidation . Much of the trade literature on oxygen-scavenging packaging presents a focus on the quantity of oxygen in a package without consideration of the widely different rates at which food quality can be degraded.
Traditionally, oxygen-sensitive foods and beverages have been packaged in such a way as to minimize their exposure to oxygen . This oxygen may be in the package at the time of sealing, or may enter the pace by permeation or leakage over the storage life. The first source of oxygen has frequently been addressed by the use of evacuation and inert-gas flushing, while the ingress has been minimized by optimal sealing and the use of high- barrier packaging materials .The approaches used to solve both oxygen problems are now recognized as providing only partial solutions, leaving options for improvements in food quality, production and distribution economics, reduction in environmental impacts, and increased convenience of use.The impact of oxygen on food quality, and ultimately shelf life, is dependent not only upon the quantity of oxygen available for chemical oxidation or support of growth of organisms but also upon the rate of the reaction which consume the oxygen. This in turn, will be influenced by solubility of the gas in the medium provided by the food or beverage. The oxidation of far in, for example, potato crisps has been shown to be highly dependent upon water activity, with a minimum rate at a_w 0.3-0.4, and the increase in reaction rate above this value is interpreted in terms of the formation of an aqueous multilayer on the food with consequent dissolution of oxygen and enhancement of the oxidation . Much of the trade literature on oxygen-scavenging packaging presents a focus on the quantity of oxygen in a package without consideration of the widely different rates at which food quality can be degraded.
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