The shells of crustaceans and molluscs contain chitin, a natural polymer that can be transformed into tiny filaments called nanofibrils. The partners involved in the n-Chitopack project use these nanofibrils to develop compostable bioplastics that offer a more sustainable alternative to petroleum-derived plastics for a variety of applications. The nanofibrils are extracted using a process patented by Italian SME MAVI Sud, the lead partner.
The project has already created a number of products based on this invention. These notably include coffee capsules, shopping bags and a variety of food packaging materials, such as hard and soft containers.
From prawns to polymers
n-Chitopack’s bioplastics are not just biodegradable; they are compostable, says project coordinator Pierfrancesco Morganti of MAVI Sud, who notes that more than 150 billion tonnes of shellfish waste are produced annually around the world. “Some things that are biodegradable actually generate toxic compounds as they break down,” he explains. “It’s important to make sure that products degrade into compounds that are of some benefit, and not harmful to humans or to the environment.”
The project’s emphasis on sustainability is not just reflected in the final product. It has shaped the entire process developed by the partners, says Morganti — starting with the extraction of the nanofibrils. Care was taken to design a method that consumes little energy, allows for recycling of all the water used in the process and generates no toxic residues. “The powder that remains at the end of the process is used as fertiliser,” says Morganti.
The resulting bioplastics could replace conventional plastics for a number of uses, such as coffee capsules, for example. “Millions and millions of these are thrown away every day, and they are usually not compostable,” Morganti notes. “This has created a problem we didn’t have before.”
The n-Chitopack partners decided to rise to the challenge and made the development of greener coffee capsules one of its priorities. The team is currently exploring options to produce their flexible, robust bio-capsules on an industrial scale.
It’s a wrap
The materials developed by n-Chitopack are based on chitin nanofibrils, but they also contain a certain amount of chitosan, another substance derived from chitin. The project has, for instance, blended the two to produce food packaging film.
This food wrap benefits from a particularly useful property that chitosan adds to the mix: it stops the growth of germs. Tests that focused on packaging fish confirmed this effect, Morganti reports. “There were no bacteria on the film that was in contact with the food,” he notes.
The full package
n-Chitopack’s bioplastics could thus help to address several problems simultaneously: they could help to reduce the vast amounts of chitin waste going to landfill, they could transform part of the world’s avalanche of discarded packaging into a slow-release supply of nutrients, and they could further protect resources by slowing down the spoilage of perishable foods.
Food packaging is, however, just one of several possible applications. Chitin nanofibrils also show promise for use in medicine, says Morganti, more specifically for the production of bandages, where the materials’ ability to keep microbes in check are particularly valuable. They also have potential for a range of environmental solutions, including filtering systems for air or water.
There are still a few technical issues to address before commercial roll-out can begin, says Morganti. However, he expects the large-scale manufacture.
Below coffee capsules made from chitin nanofibrils and polylactic acid
© n-Chitopack EU consortium