Researchers uncover alternative to plastic food packaging made from wood and starch

To help solve the issue of non-biodegradable plastic waste

Karlstad University has uncovered an alternative to plastic food packaging made from degradable material, with a biological origin.

One of the biggest problems for the environment now is plastic waste, which ends up in the oceans and harms living ecosystems. Not all plastic is recyclable, and not all recyclable plastic is completely re-usable. A biodegradable alternative must, therefore, be developed.

The institute therefore conducted research into using a mixture of starch and other polymers and discovered that these raw materials can form an equally effective protective barrier.

"Food packaging has to protect and extend the shelf life of food, and should also work during transport," said Asif Javed, a doctor in Chemical Engineering at Karlstad University.

"To meet these demands, a protective barrier is needed in paper-based packing such as those used for juice or dairy."

Plastic and paper based food packaging needs a coating to prevent water or oxygen from penetrating the packaging and spoiling the foodstuff inside. Usually this protective coating is manufactured from petroleum-based plastic.

However, the new research conducted by the university found that a mixture of lignin from wood and starch from for example potatoes or maize could potentially fulfil this function just as well as plastic.

"In my research, we used a mixture of starch and lignin to create a protective barrier that is up to scratch," explained Javed. "If new materials are to be used, they have to be at least as good as or better than petroleum-based material - regarding extending the shelf life of food, as well as the cost and effectivity of manufacture and transport.

"I have also worked with biodegradable mixtures of starch and some petroleum-based macromolecules. Although such material is not 100 per cent based on renewable resources, it has the important advantage of naturally degrading without leaving behind dangerous microplastics, should it end up in forests, lakes or oceans."

Although Javed points out that more research is still needed to replace petroleum-based materials completely in the long term.

"I hope that we will be able to do more research in this area," he added. "In our region, there are good prospects for research on fibre-based processes and products in partnership with the industry."