Active food packaging systems

In the case of natural polymers, polysaccharides like cellulose and chitosan are widely studied as antimicrobial films and barrier/coating materials. The following section reviews the recent studies on cellulose and chitosan having current and potential use as antimicrobial material for active food packaging systems. 

Marjorie S. Austero is a MS Food Science/ PhD candidate in the Materials Science and Engineering Department at Drexel University, USA. She is currently working with the Natural Polymers and Photonics Groups and her current research is focused on biopolymer materials for use in filtration and active food packaging systems. 

Modified polysaccharide biopolymers have found applications from permselective membranes to ionically conductive membranes for fuel cells. In this review, ionically selective membranes in particular will be explored. Recent studies and advances in using modified polysaccharides for food applications will also be reviewed with specific attention given to their potential uses in the development of active food packaging solutions, which include antimicrobial systems, coatings and bioactive compound delivery systems. 

Figure 10.1 Processes involved in mass transport of active agents in a food/ packaging system. ( ), non-volatile agent (o), volatile agent.

Miltz, J., Passy, N., and Mannheim, C. H. (1995). Trends and applications of active packaging systems. In "Foods and Packaging Materials—Chemical Interactions" (P. Ackermann, M. Jagerstad, and T. Ohlsson, eds.), pp. 201-210. The Royal Society of Chemistry, Cambridge, England. 

The results of the investigation contributed to the revision of framework Directive 89/109/EEC on food contact materials. In the new Eramework Regulation (EC) No. 1935/2004 the use of active and intelligent packaging systems is now included. 

Directive 2000/13/EC " deals with labelling, presentation and advertising of foodstuffs and is applicable to all foodstuffs intended for sale to consumers or caterers. Also Directive 89/107/EEC ° sets requirements on labelling of food additives. In principle, all substances used in the manufacture or preparation of foodstuffs and still present in the finished product should be declared on the label in order to inform the consumer about the substances present. It is of no interest how or when the substances are added to the food and therefore substances released from an active packaging system should be declared. 

A similar situation does not presently exist for multilayer retortable food packages. In our initial study of LEP and PEP food packages we found that there are very few experimental studies on water permeation in polymers. The studies which we did find were usually limited to low temperature, far removed from retort conditions. The effect of water activity on transport and sorption behavior has not received much attention especially for water-sensitive polymers such as EvOH. In EvOH-type systems the problem is especially acute because EvOH exhibits case II sorption at moderate humidities and its effective glass transition is depressed below storage temperatures at high humidities. Thus, modelling the transport in this type of material is very complex and does not lend itself to analysis with existing models. 

Active packaging systems exist, in which a chemical, present inside the container, absorbs oxygen or removes the products of food oxidation. 

Active packaging is the type of packaging that controls and reacts to events occuring inside the packaging. There are different types of active packaging systems, such as, antimicrobial packaging and the packaging that can provide a controlled gas environment for the food. 

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