Active Packages with Antimicrobial Properties

An antimicrobial package is a form of active package, as it interacts with the product or the headspace between the package and the food system, to obtain a desired outcome [3]. Likewise, antimicrobial food packaging acts to reduce, inhibit or retard the growth of microorganisms that may be present in the packed food or the packaging material itself [4]. 

These packages can take several forms including [4]  

2 Addition of Pads Containing Antimicrobial Agents to Packages 

The most successful commercial application of this type of package has been sachets that are either enclosed loose or attached to the interior of a package. The following three forms have predominated oxygen absorbers, moisture absorbers and ethanol vapour generators. 

Oxygen and moisture absorbers have been used in bakery, pasta, and meat packaging to prevent oxidation and water condensation. If oxygen absorbers are not exactly antimicrobial, reduction in oxygen inhibits the growth of aerobes and moulds, in the same way as moisture absorbers [5]. 

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Some antioxidants possess antimicrobial properties, such as propyl gallate and butylated hydroxy anisole, which are somewhat effective against bacteria. Butylated hydroxy toluene has demonstrated some antiviral activity. Compatibility of antioxidants with the drug, packaging system and the body should be studied carefully. For example, tocopherols may be absorbed onto plastics ascorbic acid is incompatible with alkalis, heavy metals, and oxidizing materials such as phenylephrine, and sodium nitrite and propyl gallate forms complexes with metal ions such as sodium, potassium and iron. 

Chitosan is one of the natural antimicrobial agents that widely used in active packaging. It either incorporated directly or indirectly into the film matrix. Effect of CNF incorporation into starch/chitosan composite film towards antimicrobial properties was previously studied by Salehudin et al. (2014b). Starch/chitosan composite (S C 9 1) film was prepared with starch and chitosan only while starch/ chitosan nanocomposite film (S C 9 1 +2 %CNF) was prepared by adding 2 % of CNF, chitosan and starch. Significant enhancement on the antimicrobial properties and food shelf life for both films was observed. 

Antimicrobial activity benzyl alcohol is bacteriostatic and is used as an antimicrobial preservative against Gram-positive bacteria, molds, fungi, and yeasts, although it possesses only modest bactericidal properties. Optimum activity occurs at pH below 5 little activity is shown above pH 8. Antimicrobial activity is reduced in the presence of nonionic surfactants, such as polysorbate 80. However, the reduction in activity is less than is the case with either hydroxybenzo-ate esters or quaternary ammonium compounds. The activity of benzyl alcohol may also be reduced by incompatibilities with some packaging materials, particularly polyethylene see Section 12. 

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