A new study has successfully produced a prototype of a more durable material that increases the biodegradability of food packaging by partially replacing bioplastics with cellulose fibers extracted from avocado tree branches and leaves.

Plastic allows for safe and hygienic food packaging, but its widespread use poses a significant environmental problem due to its limited recyclability and short lifespan. Therefore, the industry and the scientific community have been seeking more sustainable alternatives for decades. A recent study published by the University of Córdoba, in collaboration with the University of Girona, found a way to create a prototype of food packaging material that is more environmentally friendly, using waste that previously had no added value: avocado tree pruning residues. Spain is the main producer of avocados in Europe, with production concentrated in the Axarquia region of Malaga.

Through a semi-chemical and mechanical process in which leaves and branches are mixed with sodium hydroxide, refined, and defibrated, the study succeeded in isolating fibers from the woody residues and using them as reinforcing material, partially replacing the bioplastics used in food packaging. According to researcher Ramon Morcillo, the lead author of the paper and a researcher from the 'Bioproducts and Process Engineering' group at the University of Córdoba, the study managed to integrate cellulose obtained from avocado residues using a compatibilizing agent and at least partially reduce the use of bio-polyethylene, a type of bioplastic widely used in the packaging industry that, despite its plant origin, is not biodegradable.

Besides sustainability, this new composite has proven to be more durable, partly due to the strong mechanical properties of the natural fibers from avocado pruning residues. The study analyzed how the material performs at different fiber ratios, achieving up to a 49% increase in tensile strength.

The next step in the research line of the group, explained the author of the study, will be to evaluate other properties that are interesting to the industry; for example, the antimicrobial or antioxidant capabilities that the new composite may have, thereby opening the door to new forms of preservation that are more sustainable, specialized, and adapted to different types of products.

A few days ago, the European Parliament approved a series of measures to reduce and recycle packaging. Some types of single-use plastic packaging will be banned from 2030, which poses a real challenge for the industry: conducting market studies to assess the feasibility of those forms of sustainable packaging that have been proven feasible from a scientific standpoint. According to researcher Ramon Morcillo: "it is a detailed process that requires a lot of effort and information, but it is necessary for scaling and marketing these new materials." In the coming years, society will have to tackle this urgent challenge of reducing plastic use and promoting an economy less dependent on fossil fuels.

Source: Universidad de Córdoba