Avocado used as sustainable reinforcement for plastic packaging

With plastic pollution creating significant damage around the world, a range of more sustainable packaging solutions have been developed as alternatives, such as bio-based feedstock​ and mycelia mushrooms​. One thing that hasn’t been used much for packaging, however, is avocado.

A recent study published in the journal Advanced Sustainable Systems ​explored the potential for the use of the residues from avocado tree pruning, which would be used in bio-based polyethylene composites. They can work, the study found, as fortifications for this plastic material.

What makes avocado pruning residue a good fortification?

Avocado pruning residue is abundantly available due to the widespread popularity of avocados around the world. However, according to the study, it is often burned to create energy or used for agricultural amendments.   

The fibres within the avocado pruning residue provide good partial replacements for bio-based polyethylene which, despite being plant-based, is not biodegradable. By replacing some of this plastic, the fibres reduce the amount of it used. The functional role of the fibres within said plastic, however, is to reinforce it.

How did the researchers develop avocado pruning residue into packaging?

Through a process which involved mixing the leaves and branches of the avocado tree with soda, then refined and defibrated, the researchers were able to isolate the fibres from the pruning residue.

Once the residue had been pulped within this alkaline soda, the cellulose content of the fibre increased significantly. Cellulose, according to the study, is what gives the fibre its structural stability, and thus what makes it a good reinforcement for plastic.