Apple and orange waste can be made into edible bioplastic

In the thesis “Fruit wastes to biomaterials: Development of biofilms and 3D objects in a circular economy system,” she shows how she studied this in two types of wastes from apples and oranges.

She chose them because they are hard to dispose of and instead can be used for producing new products. It can contribute to reducing disposables in the environment.

“Both contain a lot of water and organic matter, and if they are put in landfills, they create an uncontrolled methane production. They are also hard to burn because of the water. They don’t work well as animal feed either because of the high levels of sugar and low pH,” she says.

She used two methods to create bioplastics. One is called the solution casting method, which she describes as a polymeric solution casted on a non-sticky surface that then dries to a thin bio-based film.

The other is called compression molding which is a way to use the polymers’ self-binding properties through pressure and heat to create 3D objects.

Can make waste bags for food waste

“The materials behaved differently in the different methods. Orange waste films were stronger than apple pomace films, but small holes were present in their structure. To get a uniformed surface, we needed to add a chemical with a low concentration. 3D objects from apple pomace, on the other hand, were much stronger than the ones made from orange waste. Apple pomace in both cases seemed easier to work with.”

She describes the processes as basic processes that do not require a lot of chemicals and not so high temperatures which led to materials with promising properties.

“The products from apple pomace are tastier. I have tasted almost all my products. And they are gluten free,” says Veronika Bátori.

She sees potential in creating disposables like, for example, mugs or plates when it comes to 3D objects. When it comes to plastic films, these can be used for food packaging or waste bags for food waste, since they degrade quickly.

“The materials need improvements, for example when it comes to withstanding fluid. Today, they dissolve in water and that is not a good property for a mug. So we need more research and upscaling of the production,” she says.

Text: Anna Kjellsson
Photo: Suss Wilén/Veronika Bátori
Translation: Eva Medin