Waste no more? Swedish study develops edible bioplastic films made from fruit scraps

25 Mar 2019 --- New research from the University of Borås, Sweden, has created edible, bioplastic films and 3D objects from fruit waste. Veronika Bátori, who recently received her doctorate, investigated the use of fruit waste in biomaterials in her thesis and chose to study waste from apples and oranges. Although the research for 3D shaped objects, such as mugs and plates, is in the early phase, Bátori tells PackagingInsights that the materials are promising. As the focus of the packaging industry continues to intensify on circular economy models, could edible films have a role to pay?

In the thesis, Fruit wastes to biomaterials: Development of biofilms and 3D objects in a circular economy system, Bátori chose apples and oranges because they are hard to dispose of. They can instead be used to produce new products, thereby contributing to reducing waste in the environment. The by-products of food processing industries have good potential in the production of different bio-based plastics and can be one possible way to alleviate today’s plastic pollution problems, Bátori notes in her thesis.

“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 and don’t work well as animal feed because of the high levels of sugar and low pH,” she explains.

Bátori used two methods to create the bioplastics. The first is the solution casting method, which is described as a polymeric solution cast 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.

Credit: The thesis of Veronika Bátori, from the University of Borås, Sweden.“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,” says Bátori.

She describes the processes as basic as they do not require many chemicals nor high temperatures which means the resulting materials have very “promising properties.”

Bátori also notes that the materials are tasty – with the apple pomaces being the best option taste-wise.

Potential uses and hurdles
She sees potential in creating disposables such as 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, she says.

“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.”

“To manufacture environmentally friendly materials, the choice of solution (chemicals, methods) are important,” she concludes.

Innovations in the edible packaging space are growing. A team of scientists at Samara Polytech in Russia created edible films consisting of only natural ingredients in the summer of 2018. The packaging is based on fruit or vegetable puree and low on caloric value. The product was initially designed for the nutritional diet of astronauts, as many packaging materials are inconvenient in space due to difficulties around disposal. 

However, the edible packaging of Samara Polytech can be used beyond space venture, the researchers note. It has the potential to become indispensable in the Arctic territories, on offshore oil platforms and even during long journeys. 

In a similar experimental creation, Roza Janusz, a graduate of the School of Form in Poznan, Poland, has reimagined packaging with SCOBY, an organic and sustainable material which can be eaten or composted after use. It is made of bacteria and yeast and grown through a fermentation process. 

Aside from innovative university studies, the commercial popularity of biodegradable packaging is on the rise. Innova Market Insights reports a 40 percent increase in new food and beverage products packaged in bio-based/biodegradable material (CAGR 2013-2017). Meanwhile, a survey found that more than 35 percent of German consumers, 25 percent of UK consumers and more than 25 percent of US consumers consider bio-based and/or biodegradable/compostable packaging important in food and beverage choice (Innova Market Insights, 2015).

The market researcher has also pegged “Nature’s Appeal” as its number three trend for the packaging industry in 2019, denoting a market where anti-plastic sentiment and the rising demand for designed-in recyclability have fueled a resurgence in paper and paperboard packaging. However, perhaps nothing is as “natural” as edible packaging made from fruit waste. 

By Laxmi Haigh