Waste not, want not—new approaches to forsaken food

July 25, 2018, Monash University

Australians love their food. Cooking shows have us spellbound and are rating juggernauts for TV networks, celebrity cooks and judges are treated like rock stars, and we're spending billions eating out … and in.

Revenue for the restaurants industry is estimated to be worth $20.1 billion in 2017-18, and that doesn't include the cafes and proliferating in suburban strips. The cafes and coffee shops' industry revenue in 2017-18 is estimated to be $8.3 billion.

And still, the average household spends about $237 a week on and non-alcoholic beverages, about $12,300 a year, according to the Australian Bureau of Statistics Household Expenditure Survey.

Yes, we love our food, but this story isn't about the food we love to eat. It's a story about the food we don't eat. Or more precisely, what we can do with the food we and those parts of the food we would normally throw away, such as the pith, the peel and the pips. Because there's mountains of it in landfill.

Food waste is estimated to cost the Australian economy about $20 billion every year, with consumers throwing away around 3.1 million tonnes of it. Another 2.2 million tonnes is disposed of by the commercial and industrial sector.

In a May 2018 report, Sustainability Victoria estimated that the average value of household food wastage in the state was $2136.68 a year. That equates to an estimated cost of $5.4 billion annually.

Globally, it's even more alarming. Every year around the globe, 1.3 billion tonnes of food is lost or wasted – that's one-third of all food produced for human consumption, according to the Food and Agriculture Organisation of the United Nations.

Breaking down global food losses and waste by commodity, it estimated that

  • 30 per cent of cereals products (286 million tonnes) are thrown out in industrialised countries
  • 20 per cent of dairy products (29 million tonnes) are lost or wasted every year in Europe
  • 35 per cent of fish and seafood
  • 45 per cent of fruits and vegetables
  • 20 per cent of meat
  • 20 per cent of oils and pulses
  • 45 per cent of roots and tubers.

In 2016, the Commonwealth Government released the National Food Waste Strategy: Halving Australia's food waste by 2030 report, in which it said "wastage costs the global economy around US$940 billion."

And all that food that ends up as landfill garnish? It produces eight per cent of global greenhouse gas emissions.

Further to this is the waste of resources in growing, packing, transporting and marketing the products. This includes the water, land, energy, fuel and natural resources. For example, food waste accounts for 24 per cent of the world's fresh water; it's estimated that 1000 litres of water is required to produce one litre of milk, and throwing out a kilogram of potatoes means 500 litres of water is wasted.

Generating value

Tony Patti is a professor at Monash University's School of Chemistry. In collaboration with the Indian Institute of Technology Bombay, researchers from the school are working with the Monash Food Innovation Centre, industry and farmers to help transform this food waste into profits.

They call it "biomass valorisation." The word valorisation comes from the German word verwertung, the general meaning of which is, according Wikipedia, "the productive use of a resource, and more specifically the use or application of something (an object, process or activity) so that it makes money, or generates value."

Professor Patti said biomass valorisation looks at the entire fruit or vegetable, not just what is eaten, which is what currently provides value to the grower.

"The skins, seeds, kernels, leaves and offcuts were seen as 'waste," adding to their disposal costs. These byproducts are not waste, but a potential valuable resource, providing several components, identified as being of high market value," Professor Patti said.

"Monash is working with Australian growers and businesses to diversify the potential market opportunities where these food byproducts can be recovered, including expansion into the pharmaceutical, cosmetic and pet food industries."

Which means that, in the future, that skin, seed and husk from a mango, those spent coffee grounds or pomegranate or pineapple skins could be sources of everyday health supplements, oils, antioxidants, cosmetics, organic fertilisers and even resources for making biodegradable plastics.

This also extends to fresh produce that's disposed of for not meeting 'cosmetic standards'; the misshapen apple, for instance, or the banana that's too short and has been rejected by the major supermarkets because it doesn't meet specifications.

"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," Professor Patti said.

Breaking it down

Victoria Haritos is an associate professor in Monash University's Department of Chemical Engineering. Her research combines biology and engineering to develop solutions for processing food waste.

She doesn't see, say, a tomato, like we do, a juicy red fruit. She sees its constituent parts and then focuses on developing biological processes to separate and extract those parts.

"When we look closely at the components of discarded foods such as proteins, sugars, fats, water, antioxidants, natural colours and flavours, we can see a range of valuable products that can be made from these," she said.

"We use nature's catalysts, enzymes and good microbes like yeast and lactic acid bacteria to undertake the conversion of the food," she said.

They have, for instance, been able to extract from wheat bran an antioxidant called ferulic acid, which is used in expensive cosmetic formulations.

They've also used enzymes to release starch and other sugars from waste vegetables that then becomes food for yeast that make high-value fats.

These fats, she said, can be used for a wide range of products, from biodiesel to face creams.

"We should view waste food as a resource rather than a problem," she says enthusiastically.

But she said turning food waste into viable products isn't simple, and that aspects such as the volume, availability and quality of waste need to be considered.

"Food waste has high water content so it's expensive to move around, and what are the nature and size of markets for your products derived from waste?" she asks.

"These are areas where research can help. We can match waste sources and product types in addition to developing processing technologies to convert them."

Graeme Pearson is an industrial chemist who works for an Australian-based company called Axieo. It's been collaborating with Monash for the past three years in the University's Green Chemical Futures building on the Clayton campus.

At a recent symposium on turning food waste into money organised by Monash, Pearson spoke about overseas studies that were investigating how 'nanoplatlets' in the fibre of root vegetables such as carrots and beetroots could be used to create super-strong concrete.

Or how the silica from rice husks and ground glass is being used to create lightweight low-carbon bricks that are fire and termite-resistant.

Or how the organic extract from those same rice husks was being used to make raw materials used in moisturisers and creams for cosmetics, and these materials were "synthesised at Monash."

Or how the pip from a mango, which makes up a large proportion of the tropical fruit and has a high percentage of wax, could be used to make surfboard wax.

"These sorts of collaborations between industry and academia have proven very useful for medium and long-term projects, some of which are blue-sky problems like what we do with ," Pearson said.

Explore further: Less food wasted in South Africa than in Europe

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