ABSTRACT
Modified atmosphere packaging (MAP) for meat and poultry products is a food preservation concept that is far from new. The development of plastic films many years ago made it possible to easily and cheaply enclose meat products in clear films and to incorporate preservative gases with the closed atmosphere to improve product shelf life and appearance. Carbon dioxide (CO2) gas has been recognized as a preservative agent for meat and poultry for well over 100 years (Rao and Sachindra 2002), and consequently, use of carbon dioxide gas in MAP has been studied extensively (Brooks 1933; Clark and Lentz 1969; Gill and Jones 1996; Gill and Tan 1980; Kraft and Ayres 1952; Livingston, Breuer, Killifer, Bidner, and McKeith 2004; Sebranek 1985). Various other gases including nitrogen, oxygen, and carbon monoxide have been studied more recently as MAP technology for meat and poultry products has continued to develop (Kropf 2004). The interest in commercial applications for MAP systems has increased tremendously in the past 20 years or so because more and more meat and poultry products are processed in centralized facilities followed by transportation over increasingly long distances. As a result, it has become critical for the industry to increase the shelf life of meat and poultry products as much as possible to consistently deliver wholesome, high-quality products to consumers. Consumers demand, and have come to expect, fresh, high-quality food products, and the role of packaging systems such as MAP has become increasingly important to meet consumer expectations. New developments in flexible film properties and new technology for gas handling and packaging equipment have facilitated the development of an increasingly sophisticated body of scientific knowledge about MAP systems.
