Dear Colleagues,

Traditionally, food packaging materials were chosen so as to avoid undesirable physical, chemical and biological interactions between the contained food and the environment. Packaging in this case functioned mainly as a protective but ‘passive’ barrier against the above mentioned effects. During the past two decades, active packaging materials were, and are still being, developed which interact with food with the objectives of maintaining food quality and/or enhancing the safety of the packaged product (EU Regulations 1935/2004/EC and 450/2009/EC). Active packaging can serve a number of specific purposes such as to prevent the food from oxidation reactions of lipids and proteins (antioxidant packaging), to inhibit the growth of spoilage and/or pathogenic microorganisms (antimicrobial packaging), to perform a specific reaction i.e. breakdown of lactose in milk, lowering of cholesterol and triglycerides, production of desirable flavor compounds in a particular food matrix, etc. or even, in the form of Bioactive Packaging, to exert a beneficial health effect on the consumer as a result of designed migration of bioactive compounds/additives from the packaging material into the packaged food. In all above cases, functional additives should be approved as indirect food additives since upon migration they become food constituents.

Of the various types of active packaging, those that exert an antioxidant and antimicrobial effect are those that are most important for the food industry. Active compounds added into the packaging material may be either synthetic or natural. Likewise, the packaging material may be either conventional or biodegradable. The antioxidant or antimicrobial compound may be added in the form of a pad, sachet, label, etc. or may be incorporated into the packaging material matrix or even coated onto the internal surface of the packaging material. Thus, antioxidant/antimicrobial packaging has become a great interest for polymer scientists and packaging engineers. Furthermore, the recent use of nanotechnology in the form of nano-particles in active packaging applications seems very promising for food preservation purposes. This, in turn, has opened a new field for nanotechnology research.

Active packaging materials function either as absorbers (oxygen, carbon dioxide, ethylene, moisture) or emitters (carbon dioxide, essential oils, organic acids).

Antimicrobial and antioxidant active packages function as controlled release systems, which are a new generation of materials that can release active compounds at different controlled rates, suitable for improving the quality and safety of foods during storage. Such a package behaves effectively as a reservoir to the active compound, which is released into the food according to a predetermined pattern throughout the entire expected storage time. To achieve this goal, the active molecules need to be encased properly in the packaging, ensuring their proper release into the packaged food. Factors such as release rate, properties of packaging material (e.g. gas permeability, mechanical properties, etc.) are directly related to package structure, morphology of blended polymer and localization of active compounds. These, in turn, are affected by processing methods such as cast film, blown film, smart blending, lamination/co-extrusion, solution casting/coating, etc. Therefore, type and ratio of the polymer/s and the property of active compound should be carefully taken into account during the design and development of active packaging.

This special issue will attempt to bring together food scientists, polymer scientists and engineers as well as nanotechnologists from around the world working on Antioxidant and Antimicrobial Packaging films, presenting the state-of-the art in a field of science/technology that is presently being shaped.

Prof. Michael Kontominas
Prof. Dr. Anastasia Badeka
Guest Editors

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• active packaging
• antioxidant packaging films
• antimicrobial packaging films
• food preservation
• food quality
• food safety