6 - Antimicrobial packaging systems

Abstract

Antimicrobial packaging is a system that can kill or inhibit the growth of microorganisms and thus extend the shelf life of perishable products and enhance the safety of packaged products. Among many applications, such as oxygen-scavenging packaging and moisture-control packaging, antimicrobial packaging is one of the most promising innovations of active packaging technologies. It can be constructed by using antimicrobial packaging materials and/or antimicrobial agents inside the package space or inside foods. Most food packaging systems consist of food products, the headspace atmosphere, and the packaging materials. Any one of these three components of food packaging systems could possess an antimicrobial element to increase antimicrobial efficiency. Besides the use of antimicrobial packaging materials or antimicrobial inserts in the package headspace, gaseous agents have been used to inhibit the growth of microorganisms. Common gases for modified atmosphere packaging are carbon dioxide, sulfur dioxide for berries, and ethanol vapor for confections. These gases are injected into the package headspace or into palletized cases after shrink-wrapping of a unit load on a pallet. Vacuum, nitrogen-flushing, and oxygen-scavenging packaging, which were originally designed for preventing the oxidation of packaged foods, also possess antifungal and antimicrobial properties against aerobic bacteria as a secondary function, since these microorganisms are restrictively aerobic. However, these technologies, which control the low oxygen concentration to inhibit the growth of aerobic microorganisms, could cause the onset of anaerobic microbial growth. Controlling anaerobic bacteria in modified atmosphere packaging is a very important issue in maintaining the quality and safety of the products.