The browning bananas on your kitchen counter could be transformed into the plastic packaging that contains your next garden salad.
Scientists say they have found a way to divert food from landfill and convert it into biodegradable plastic wraps and cellophanes.
Food waste accounts for about 3 per cent of the country’s annual greenhouse gas emissions and flushes away more than 6 trillion litres of water — emptying 1,000 Olympic-size swimming pools would only use 2.5 billion litres.
Almost 8 million tonnes of food worth about $40 billion are wasted each year in Australia, through on-farm and supply chain losses, in restaurants and supermarkets.
But households discard the most food, throwing away about one-third of all organic refuse.
Researchers, who are focused on tackling the problem, say better packaging and use-by-date guidance are central to cutting back the waste.
Protection or problem?
Food Innovation Australia’s national food waste strategy argues reducing household food waste will require consumer behaviour change coupled with technical developments in packaging, and recommends improved portioning and better food date labelling.
According to Stop Food Waste Australia, a partnership tasked with implementing the waste reduction roadmap, about half of all food waste is fresh produce.
The partnership says it aims to improve packaging and product labelling, and “transform surplus food and food processing wastes into new upcycled food products and ingredients”.
The Australian Fresh Produce Alliance also says that while packaging can extend the shelf life of fresh food, it must reduce packaging and find ways to produce plastic packaging from recycled materials.
That’s exactly what Federation University food scientist Dylan Liu hopes to achieve by turning food waste into food packaging.
Tiny material, big potential
Cellulose is a fibre found in plants, fruits and vegetables.
Nanocellulose is a tiny cellulose fibre that Dr Liu says is strong and flexible, making it ideal for food storage because it can be used to create cling film and other transparent packaging.
Scientists say nanocellulose packaging made from food waste could be ready to hit the shelves soon.
“We’re taking food waste and then we add certain types of microorganisms, and the bacteria is going to use the nutrients in the food waste and generate the nanocellulose material out of that,” Dr Liu says.
“One of the most exciting applications is in smart packaging. We can embed food extract pH responsive compounds in the nanocellulose and then create a smart label that reflects the shelf life of food products.”
Acidity changes in packaged food will trigger a colour change in the smart label, which will tell the consumer if food is still safe to eat, Dr Liu says.
These colour-changing labels have the potential to replace use by dates.
“Quality and safety are so important in the food industry, so if we can monitor that more closely it can potentially help people improve their health,” Dr Liu says.
Circular economy
Nanocellulose technologies have been in the works for a while, but published research has increased over the past couple of years and the global nanocellulose market is expected to triple by 2025.
Studies have noted that some nanocellulose production techniques are energy intensive and involve harsh synthetic chemicals.
Dr Liu says his process, which is currently under peer review at a science journal, is unique because it uses food waste.
“This certainly brings down the cost of the material,” Dr Liu says.
“We take the circular economy perspective into the design of the process, so we can use all the materials generated from the process, which means no secondary waste.”
Nanocellulose derived from food waste is biodegradable and safe in a range of fields, Dr Liu says, and the by-products of the production process can be used as a liquid fertiliser and solid feed for livestock.
“It won’t need too much energy input and the process happens at room temperature – around 22 degrees [Celsius],” he says.
“It’s also a relatively short process, which only takes a couple of days to generate a batch of material.”
And while Dr Liu says nanocellulose production isn’t the answer to all of Australia’s waste problems, it could go some way towards repurposing food that would otherwise be discarded.
This all means that the country’s major food waste offenders could one day be the source of new food packaging.
“I think we are really close to a pilot trial,” Dr Liu says.
“We have tried different types of food waste in our lab, which are very encouraging. At this stage, we are looking for partners who are willing to donate some waste.”
