While already in 1992 waxes were used for fruit preservation, only in recent years has the development and application of edible films and coatings in the food industry increased, and with that also the scientific studies around it (FPF reported). Two reviews published in June 2021 summarize the latest developments and findings on the topic.
The article by Bizymis and Tzia from the National Technical University of Athens, Greece, in the peer-reviewed journal Critical Reviews in Food Science and Nutrition elaborates on the different components (polysaccharides, proteins, and lipids) used to produce edible films or coatings, the methods to apply them on the product, and the requirements for different food categories. The requirements of a coating depend on which individual properties of a food must be protected. The authors looked at coating requirements for six food categories: fruits and vegetables, meat, seafood, cheese, bakery and confectionery products, and deep fat fried products. Also discussed are composite or multi-component films as well as nanomaterials. According to the authors, nanomaterials represent an emerging technology the industry is moving towards to further increase mechanical and barrier properties of edible films and coatings. However, further studies on the potential health impacts of nanomaterials after consumption are needed “to develop nano-systems that can be used lawfully and safely in commercial products.”
In a mini-review, published in the Journal of Food Measurement and Characterization, Paidari and coauthors, also summarize the application of polysaccharide- and protein-based edible coatings and the addition of nanomaterials. Moreover, the article covers chitosan-, lipid-, as well as fruit and vegetable-based edible coatings. The article highlights that the use of food waste for edible films and coatings “not only can reduce the costs of the food industry dramatically but also can improve the quality of packed foodstuff.” More recently, the addition of essential oils to edible coating has been studied since these oils have antimicrobial and advantageous physicochemical properties. The authors believe that the uses of food waste, essential oils, and nanoparticles are cost-effective and efficient options for improving the quality of the packaged good.
Edible films and coatings build a semi-permeable barrier on the food product, protecting it against microorganisms as well as physical, chemical, and mechanical damage. Thus, the barrier helps to extend the product’s shelf life without changing its quality. Both coatings and films can be consumed with the food, but while coatings are directly applied to the product by dipping or spraying, films are first finished and then wrapped around the food (see Bizymis and Tzia). Besides coatings and films, edible packaging such as water bottles (FPF reported), six-pack rings (FPF reported), and edible labels (FPF reported) have been developed.
Bizymis A.-P. and Tzia C. (2021). “Edible films and coatings: properties for the selection of the components, evolution through composites and nanomaterials, and safety issues.” Critical Reviews in Food Science and Nutrition (published online June 8, 2021).
Paidari. et al. (2021). “Edible coating and films as promising packaging: a mini-review.” Journal of Food Measurement and Characterization.