Lots of fresh food produce is packaged in transparent plastic. That material has two main advantages: it keeps the food fresh and you can see the food inside the packaging. But, it is not sustainable. Directly after opening it is thrown away.

Cellulose from orange peel

Douglas Hayden is a PhD candidate from the Debye Institute for Nanomaterials at Utrecht University. Together with colleague Srivatssan Mohan, he developed a potential sustainable alternative for this type of plastic food packaging. “It is made from a waste source of cellulose from the inside of orange peels. Cellulose is the main component of paper and fully biodegradable, but our ‘nanopaper’ is made from cellulose fibres which are a thousand times thinner than the fibres in normal paper. This makes it transparent.

Simple production process

In order to be a good food packaging material, the paper should also be able to keep food fresh. Therefore, it must also be able to block UV light. “Our nanopaper contains UV-absorbing nanoparticles. These are easy to make from cellulose with help from ethanol, a.k.a. alcohol, and water.” The rest of the production process is also impressively simple. Hayden: “We added the nanoparticles to a cellulose fibre mixture and filtered this. Afterwards, we put the substance in an oven for ten minutes at 50 degrees Celsius and this resulted in the transparent, UV-blocking nanopaper. The process is also completely upscalable.”