For a long time polymers have supplied most of common packaging materials because they present several desired features like softness, lightness and transparency. However, increased use of synthetic packaging films has led to a serious ecological problems due to their total non-biodegradability. Although their complete replacement with eco-friendly packaging films is just impossible to achieve, at least for specific applications like food packaging the use of bioplastics should be the future. The aim of this review was to offer a complete view of the state of the art on biodegradable polymer packages for food application.

Biodegradable polymers for food packaging: a review

Research and development of antimicrobial materials for food applications such as packaging and other food contact surfaces is expected to grow in the next decade with the advent of new polymer materials and antimicrobials. This article reviews the different types of antimicrobial polymers developed for food contact, commercial applications, testing methods, regulations and future trends. Special emphasis will be on the advantages/disadvantages of each technology.

Review of antimicrobial food packaging

Natural-based plasticizers and biopolymer films: A review

Research and development of bio-nanocomposite materials for food applications such as packaging and other food contact surfaces is expected to grow in the next decade with the advent of new polymeric materials and composites with inorganic nano-particles. This article reviews different types of new bio-based materials, such as edible and biodegradable nanocomposite films, their commercial applications as packaging materials, regulations and future trends. Special emphasis is given to the advantages of nanotechnology application in order to improve the mechanical and oxidation stability, the barrier properties, and eventually the biodegradability of conventional polymeric matrices.

Potential perspectives of bio-nanocomposites for food packaging applications

The growing ecological and environmental consciousness has driven efforts for development of new innovative materials for various end-use applications. Polymers synthesized from natural resources, have gained considerable research interest in the recent years. This review paper is intended to provide a brief outline of work that covers in the area of biocomposites, major class of biodegradable polymers, natural fibres, as well as their manufacturing techniques and properties has been highlighted. Various surface modification methods were incorporated to improve the fibre–matrix adhesion resulting in the enhancement of mechanical properties of the biocomposites. Moreover, an economical impact and future direction of these materials has been critically reviewed. This review concludes that the biocomposites form one of the emerging areas in polymer science that gain attention for use in various applications ranging from automobile to the building industries.

A review of the recent developments in biocomposites based on natural fibres and their application perspectives

Edible films or coatings have provided an interesting and often essential complementary means for controlling the quality and stability of numerous food products. There are many potential uses of edible films (e.g. wrapping various products, individual protection of dried fruits, meat and fish, control of internal moisture transfer in pizzas, pies, etc.) which are based on the films properties (e.g. organoleptic, mechanical, gas and solute barrier). Polysaccharide (cellulose, starch, dextrin, vegetable and other gums, etc) and protein (gelatin, gluten, casein, etc) based films have suitable mechanical and organoleptic properties, while wax (beeswax, carnauba wax, etc) and lipid or lipid derivative films have enhanced water vapour barrier properties. The film-forming technology, solvent characteristics, plasticizing agents, temperature effects, solvent evaporation rate, coating operation and usage conditions of the film (relative humidity, temperature) can also substantially modify the ultimate properties of the film.

Technology and applications of edible protective films

At low relative humidity (RH), an edible wheat gluten film presents very low oxygen and carbon dioxide permeabilities [1.24 and 7.4 amol/(Pa m s), respectively, at 25 °C]. For higher than 60% RH, O2 and CO2 permeabilities increase exponentially [to 1290 and 36 700 amol/(Pa m s), respectively, at 95% RH], presumably due to the plasticizing effect of water molecules. Pectin, chitosan, pullulan, and myofibrillar protein films are also very permeable to O2 and CO2 at high RH. The selectivity ratio (CO2/O2 permeability) of all films tested at high RH was very high (from 10 to 28) as compared to conventional synthetic films (4 to 6). Keywords: Edible film; gas permeability; relative humidity

Influence of Relative Humidity and Film Composition on Oxygen and Carbon Dioxide Permeabilities of Edible Films

Chemical (vapors of formaldehyde), physical (temperature, UV and γ radiation), and aging treatments were applied to wheat gluten films. Changes in film mechanical properties, water vapor permeability, solubility, and color coordinates were investigated. An aging of 360 h led to a 75 and 314% increase in tensile strength and Young's modulus, respectively, and a 36% decrease in elongation. Severe thermal (above 110 °C, 15 min) and formaldehyde treatments highly improved the mechanical resistance of the films. Under these conditions, up to 376 and 654% increase in tensile strength and Young's modulus and up to 66% decrease in elongation have been observed. Water solubility was only slightly modified, whereas water vapor permeability was not affected. Color coordinates of films heated above 95 °C changed to a great extent. An almost total insolubilization of proteins in sodium dodecyl sulfate occurred for heat- and formaldehyde-treated films, due to the modification of protein network leading to changes in pr...

Properties of chemically and physically treated wheat gluten films.

Certain newly discovered characteristics of natural biopolymers should make them a choice material to be used for different types of wrappings and films. Edible and/or biodegradable packagings produced from agricultural origin macromolecules provide a supplementary and sometimes essential means to control physiological, microbiological, and physicochemical changes in food products. This is accomplished (i) by controlling mass transfers between food product and ambient atmosphere or between components in heterogeneous food product, and (iii) by modifying and controlling food surface conditions (pH, level of specific functional agents, slow release of flavour compounds), it should be stressed that the material characteristics (polysaccharide, protein, or lipid, plasticized or not, chemically modified or not, used alone or in combination) and the fabrication procedures (casting of a film-forming solution, thermoforming) must be adapted to each specific food product and usage condition (relative humidity, temperature). Some potential uses of these materials (e.g. wrapping of various fabricated foods; protection of fruits and vegetables by control of maturation; protection of meat and fish; control of internal moisture transfer in pizzas), which are hinged on film properties (e.g. organoleptic, mechanical, gas and solute barrier) are described with examples.

Recent innovations in edible and/or biodegradable packaging materials

Edible films and coatings are traditionally used to improve food appearance and conservation. The most common examples are wax coatings for fruit (used in China since the 12th century), chocolate coatings for confectionery, lipid films to protect meat products, and soy milk-based lipoprotein films to improve the appearance and preservation of certain foods in Asia.

Stéphane Guilbert

Papers

Technology and applications of edible protective films

Influence of Relative Humidity and Film Composition on Oxygen and Carbon Dioxide Permeabilities of Edible Films

Properties of chemically and physically treated wheat gluten films.

Recent innovations in edible and/or biodegradable packaging materials

Edible films and coatings as active layers