Researchers in Australia have discovered a way to turn banana plantation waste into packaging material that they say is biodegradable and recyclable.
The technique, developed at the University of New South Wales (UNSW), takes the pseudostems of the banana plant and converts the waste into nanocellulose, which can be used to create packaging.
According to the researchers, the banana industry produces large amounts of waste, with only 12% of the plant being used (the fruit) while the rest is discarded after harvest.
“What makes the banana-growing business particularly wasteful compared to other fruit crops is the fact that the plant dies after each harvest,” said associate professor Jayashree Arcot.
“We were particularly interested in the pseudostems – basically the layered, fleshy trunk of the plant which is cut down after each harvest and mostly discarded on the field. Some of it is used for textiles, some as compost, but other than that, it’s a huge waste.”
Using a supply of pseudostem material from banana plants grown at the Royal Botanic Garden Sydney, the researchers set to work in extracting cellulose to test its suitability as a packaging alternative.
“The pseudostem is 90% water, so the solid material ends up reducing down to about 10%,” Arcot said. “We bring the pseudostem into the lab and chop it into pieces, dry it at very low temperatures in a drying oven, and then mill it into a very fine powder.
“We then take this powder and wash it with a very soft chemical treatment. This isolates what we call nanocellulose, which is a material of high value with a whole range of applications. One of those applications that interested us greatly was packaging, particularly single-use food packaging where so much ends up in landfill.”
When processed, the material has a consistency similar to baking paper. Depending on thickness, the material could be used to make trays for meat and fruit or shopping bags.
The researchers say that for the banana pseudostem to be a realistic alternative to plastic bags and food packaging, it would make sense for the banana industry to start the processing of the pseudostems into powder that they could then sell to packaging suppliers.
Arcot said: “If the banana industry can come on board, and they say to their farmers or growers that there’s a lot of value in using those pseudostems to make into a powder which you could then sell, that’s a much better option for them as well as for us.”
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