Growing the market

Researchers from Monash University are developing methods of unlocking the value from uneaten parts of fruit and vegetables to return their value to the economy.

In a spur-of-the-moment purchase, you buy a mango at your local green grocer. They’re in season, it was cheap and it supports Australian farmers. Unfortunately, in a situation all too common, that mango sits in the fruit bowl and goes off.

As it is scraped into the bin, that mango joins the 3.1 million tonnes of edible food that is thrown away every year by Australian households, according to the National Food Waste Strategy. That $2.50 piece of fruit has become part of the $20 billion loss to the economy.

While discarded food waste from households is a major contributor to the food waste issue, wastage occurs across all steps of the supply chain, according to the strategy. The report says the commercial and industrial sectors waste 2.2 million tonnes of food, which can result in lost revenue from significant waste disposal charges and lost business.

Falls in market prices, spoilage due to improper temperature control and poor stock management are just some examples the strategy says can create food waste. Researchers from the University of the Sunshine Coast also found up to 87 per cent of undamaged, edible tomatoes were rejected and – in some cases – not even financially worth harvesting.

To help farmers turn this waste into a profit, researchers from Monash University’s Food Innovation Centre and School of Chemistry have joined forces with the Indian Institute of Technology Bombay to extract high value components from biomass.

Known as biomass valorisation, the process uses the entire fruit or vegetable to provide value for the grower or manufacturer.

Monash University is working with farmers and businesses to increase the number of potential market opportunities for products made from this upvalued food waste.

The research aims to be implemented across the supply chain. Farmers could retain value from their harvested fruit and vegetables that do not meet supermarket aesthetic standards, while processing plants and distribution centres could capture the byproducts or the stock.

Tony Patti from Monash University’s School of Chemistry, says that the byproducts of fruits such as mangos, pineapples and pomegranates can be used for higher value applications instead of compost or animal feed.

“Currently, mangos are mostly used for their flesh, with their skin, seed and husk being disposed of. However, the pip from a mango has a high amount of wax which could be used to make surfboard wax,” he explains.

“Pineapples are also a rich resource of byproducts, with the stems being rich in the enzyme bromelain, which has the potential as a meat tenderiser or for some therapeutic agents and vitamins. Only half of the actual fruit is eaten, with the rest being thrown out.”

Pomegranates have also been identified as a potential source of valuable byproducts, as their peels can be used to produce biodegradable polymers and are rich in pectin, a food additive used as a gelling agent. The seeds are also rich in omega−3 fatty acids, which could be captured and used to create vitamin supplements.

Often these resources are discarded at a processing plant, where the flesh of the fruit is used to create juices to be used in certain salads and recipes. However, because the plant produces a pure source stream of biowaste, it can potentially be captured to make high value products.

Tony says that collecting a single stream of biomass creates additional potential to then use it in the pharmaceutical, cosmetic and pet food industries to provide more value to the seller than if it were to be sent to compost.

“Using this research, food and agricultural companies can tackle costly waste challenges, improve their environmental footprint and create a sustainable business that takes full advantage of growing demand in domestic and export markets for high-quality products,” Tony adds.

“When there is a high volume of pure stream byproduct, you have the perfect opportunity to capture it and divert it from the waste stream. In some cases, the food processing centre can become a sort of biorefinery, similar to how the petroleum industry produces a range of products from crude oil.

“The same concept applies to food production. For example, if there is a processing plant that is only using the flesh of the pineapple in tins, it would be able to exploit the skins, cores and stems to extract additional value.”

Researchers are currently investigating the potential benefits of components of fruits and vegetables that are shared between Australia and India’s climates, including mango, pineapple, pomegranate, soy beans, spent coffee grounds and almond ash. 

Chemical company Axieo has also collaborated with Monash University to research additional solutions to extract silica from rice husks and ground glass to create lightweight, low-carbon bricks that are resistant to fire and termites.

Tony adds that the waste industry could be vital to ensuring the research is able to translate into the economic benefits, providing the infrastructure necessary for the collection and transport of the waste.

“This research relies upon good science and engineering across multiple disciplines, but where green and sustainable chemistry principles are central.”