A team from the US Department of Agriculture (USDA) is working on producing these from casein, a protein derived from cow’s milk. It reported its latest progress in this field to a meeting of the American Chemical Society held on 21 August.
Casein films were shown in a number of applications including films and wraps for oxygen-sensitive foods, like cheese. By adding citrus pectin to the bioplastic blend the USDA researchers improved its flexibility, temperature performance and resistance to humidity, producing a solution that is ‘up to 500 times better than plastics at keeping oxygen away from food.’
The new films do not consume petrochemicals, are biodegradable and edible.
Co-leader of the study Laetitia Bonnaillie explains: ‘The coatings applications for this product are endless. We are currently testing applications such as single-serve, edible food wrappers. For instance, individually wrapped cheese sticks use a large proportion of plastic — we would like to fix that.’
In addition the casein technology is being positioned as a healthier alternative to sugar-based coatings to prevent breakfast cereals becoming soggy in milk. Another application is as a moisture- and grease-resistant coating for paper packaging like pizza boxes. In future it may also be possible to add flavouring to the casein coatings.
The current timeline is to evolve the technology into commercial products that will be in use on supermarket shelves by 2019.
This article comes from Food Contact World, which provides exclusive news and analysis on developments in digital print trends, markets, and technologies.