Plastic-free bioactive paper coating used to make sustainable food packaging

Plastic packaging used to protect food contributes significantly to the increasing amount of plastic pollution in the world. Most cheeses, meats, and even fruits and vegetables come in plastic wrappers, not to mention all the other things in a grocery store like crackers, cookies, candy, etc. This method is hygienic, protecting the food as it travels to your home. However, these fossil fuel-based plastics are bad for the planet.

In Germany alone, citizens generated 38.5 kilograms of plastic waste per capita in 2017. That’s a lot of plastic for a country in just one year. The country exports this plastic waste to Asian or African countries (as many countries do) for disposal and much of it ends up in the oceans. There, it harms sea creatures and breaks down into microplastics, which eventually end up in our food, potentially damaging us too. Therefore, reducing plastic packaging is a necessity.

This is why researchers from Fraunhofer-Gesellschaft have developed an innovative and sustainable solution for food packaging within the framework of the “BioActiveMaterials” project. They created a ecological coating for paper packaging, which they use to make wrapping paper and resealable bags that can be used with any type of food – fresh, cooked or frozen.

The team made the coating from proteins and waxes with bio-based additives. They cover the inner surface of the paper – applied in liquid form using standard roll-to-roll technology. It keeps food fresher longer, just like conventional packaging. The antioxidants in the coating even extend the shelf life of foods.

Dr. Michaela Müller, Head of Functional Surfaces and Materials Innovation at Fraunhofer IGB, explained:

First, proteins act as an oxygen barrier layer while waxes form a water vapor barrier, preventing fruits, for example, from drying out quickly. Second, the bio-based additives have an antioxidant and antimicrobial effect. This prevents meat and fish from spoiling so quickly. Overall, food has a much longer shelf life.

The paper is guided on rollers in the coating process and provided with “bioactive materials” via an aqueous dispersion. (Credit: © Fraunhofer)

The wax protects against ink transfer beyond the paper so that a producer can have their logo and nutritional information (required by food law) printed on the packaging, without hassle.

The raw materials used to make the coating are natural substances already approved for use in the food industry. The protein component comes from lupine, rapeseed, sunflower or whey. It could even come from unused waste from farms. The wax is made from beeswax and wax produced from the Brazilian carnauba palm and the Mexican candelilla bush.

Muller explained:

We chose these waxes because they are biodegradable, approved for food contact and easily available on the market.

After use, the packaging can be disposed of or recycled. The coating will not hinder the recycling process.

Dr Cornelia Stramm, Head of Department at the Fraunhofer Institute for IVV Process and Packaging Engineering, said:

After use, the packaging is placed in the waste paper recycling bin, the coating is biodegradable and does not hinder the recycling process.

This innovative solution benefits the environment, consumers and retailers. Buyers are increasingly aware of the damage their purchasing choices can do and have opted for items in resource-efficient, plastic-free and biodegradable packaging.

Project partners are now experimenting with concepts for applying the coating directly to foods such as fruits or vegetables to extend their shelf life. Edible coatings are harmless.

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