How banana plant stems can be made into new kind of sustainable packaging
Only 12 per cent of the banana plant is used - the fruit. The rest of the plant dies after each harvesting and in many cases, is left to rot in plantation fields. Pictures: Shutterstock, UNSW/Richard Freeman
When the plant dies, new shoots emerge from the rhizome, or underground stem which then go on to form the next pseudostem and banana plant.
UNSW researchers have found a way to put the banana pseudostems to good use. First they dry them at low temperatures.
Next they mill the dried pseudostem into a fine powder before putting it into an alkaline solution to extract the all-important nanocellulose.
Once the nanocellulose is extracted, it can be fashioned into plastic films of varying thicknesses.
The researchers have been experimenting with different consistencies to find which are most suitable for packaging.
When poured more thickly, the plastic film may be suitable for food trays used to contain fresh food sold in supermarkets.
A thinner, translucent version of the film has a consistency similar to baking paper and suitable for supermarket shopping bags. The plastic is biodegradable and can be recycled four times without degrading.
Associate Professor Jayashree Arcot, Professor Martina Stenzel and researcher Kehao Huang will next look at how to make the plastic more hydrophobic - or resistant to water.
Scientists from UNSW Sydney have created a new type of packaging material from discarded banana plant 'pseudostems'.