Controlled and Modified Atmosphere PackagingEmrah Kirtil and Mecit H Oztop, Middle East Technical University, Ankara, Turkey

! 2016 Elsevier Inc. All rights reserved.

To prolong the shelf life of foods, it is crucial to minimize the rates of biochemical, enzymatic, and microbial degradationreactions. Commonly, this is achieved by ensuring proper sanitation conditions during slaughter or harvesting, processingfoods to reduce water activity and damage enzyme functionality, and providing optimum temperature and relativehumidity conditions during storage (Kader et al., 1989). Despite these precautions, air surrounding the foods continuesto provide a suitable medium for oxidative rancidity reactions, as well as growth of aerobic microorganisms. Hence, alter-ation of the atmosphere around the food could help preserve its quality. Modified atmosphere packaging (MAP) is definedas the enclosure of a packaged food with an optimal gas composition that is specifically designed to extend its shelf lifeand is different from atmospheric gas composition (Church and Parsons, 1995). In controlled atmosphere storage (CAS),a fixed predetermined concentration of gases is maintained by constant addition or removal of gases during storage ofunpackaged foods. In modified atmosphere (MA), unlike controlled atmosphere systems, no further control is exertedover the food after modification of the initial gas composition (Robertson, 2012; Kader et al., 1989). The positive effectsof MA on preserving freshness of foods were first reported in 1821, when Jacques Etienne Berard (a professor at School ofPharmacy at Montpellier in France) claimed that storage of fruits and vegetables under low O2 concentrations retardedripening (Robertson, 2012). First commercial applications involved the use of CAS to safely transport fruits in the holdsof ships under decreased O2 concentrations (Davies, 1995; Mullan and McDowell, 2003). The increasing research on thesubject has made commercial packaging application available by early 1970s. The initial commercial applications concen-trated on red meat, bacon, fish, processed meats, and cooked shellfish. Today, the high consumer demand forlonger-shelf-life foods without the addition of preservatives has made MAP available for a wide range of foods including-meat, poultry, fish, bakery products, potato chips, cheeses, salads, fruits, and vegetables (Davies, 1995; Mullan andMcDowell, 2003; Robertson, 2012).

Table 1 lists some of the applications of MAP, with the gas compositions used (Parry, 1993). In most of the MAP foods, O2 iscompletely excluded and replaced by either CO2 or N2 or a combination of both. Exceptionally, for fruit and vegetables, increasedrespiration rates in the presence of oxygen result in with faster ripening and ethylene (C2H4) formation. That is why, to decrease therate of respiration, it is crucial to use the minimum O2 concentration possible without triggering anaerobic fermentation (Kaderet al., 1989; Yam and Lee, 1995). Similarly for red meat, oxygen cannot be excluded from the package as only in the presence ofO2, myoglobin can be maintained in its oxygenated form of oxymyoglobin which gives meat its signature attractive red appearance(Robertson, 2012).

CAS and MAP, though simple in concept and execution, are very effective and increasingly applied to many foods, providingincreased shelf lives for low costs. Considering how effective and cost-efficient these technologies are, they might prove to beone of the most dominant preservation techniques in the twenty-first century.

Table 1 Recommended gas mixtures for modified atmosphere packaging (Parry, 1993)

Product Oxygen (%) Carbon dioxide (%) Nitrogen (%)

Red meat 60–85 15–40 –

Cooked/cured meat – 20–35 65–80Poultry 25 75Fish (oily) – 60 40Hard cheese – 100 –

Soft cheese – 30 70Bread 60–70 30–40 –

Nondairy cakes – 60 40Dairy cakes – – 100Pasta (fresh) – – 100Fruits and vegetables 3–5 3–5 85–95Dried/roasted foods – – 100

Reference Module in Food Sciences http://dx.doi.org/10.1016/B978-0-08-100596-5.03376-X 1

References

Church, I.J., Parsons, A.L., 1995. Modified atmosphere packaging technology – a review. J. Sci. Food Agric. 67, 143–152. Available at: http://doi.wiley.com/10.1002/jsfa.2740670202.

Davies, A.R., 1995. Advances in modified-atmosphere packaging. In: Gould, G.W. (Ed.), New Methods of Food Preservation SE – 14. Springer, US, pp. 304–320. Available at:http://dx.doi.org/10.1007/978-1-4615-2105-1_14.

Kader, A.A., Zagory, D., Kerbel, E.L., 1989. Modified atmosphere packaging of fruits and vegetables. Crit. Rev. Food Sci. Nutr. 28 (1), 1–30.Mullan, M., McDowell, D., 2003. Modified atmosphere packaging. Food Packag. Technol. 303–339.Parry, R.T., 1993. In: Parry, R.T. (Ed.), Principles and Applications of Modified Atmosphere Packaging of Food. Blackie, Glasgow, UK, pp. 1–18.Robertson, G.L., 2012. Food Packaging: Principles and Practice. Taylor & Francis.Yam, K.L., Lee, D.S., 1995. Design of modified atmosphere packaging for fresh produce. In: Active Food Packaging.

2 Controlled and Modified Atmosphere Packaging