Reducing carbon emissions will mean changing the food we eat. Luckily, food engineering is coming to the rescue.
There’s no getting around it: modern food production is responsible for more than a third of human-induced greenhouse gas emissions.
Animal-based foods account for about twice the emissions of plant-based ones.
In a world where emissions are already too high, and the global population is due to rise another 25 per cent to 10 billion by 2057, attention is shifting to how we can re-engineer the carbon footprint of our food.
This is one of the challenges that researchers at the University of Sydney’s Centre for Advanced Food Engineering (CAFE) are working to answer.
Through the development of technologies that promote sustainable food systems, as well as good health and nutrition, their work includes the creation of alternative protein sources for manufacturing innovative and nutritional food.
“We need to reduce our reliance on meat, but that requires creating foods that provide the same kind of satisfaction,” said CAFE Director, chemical engineer Professor Fariba Dehghani, who leads a cross-disciplinary group of industry-focused researchers specialising in engineering, agriculture, nutrition, chemistry, molecular biology and medicine.
“Livestock accounts for about 77 per cent of farming land but contributes about 37 per cent of total protein,” she said.
“Plants are a much higher source of protein, but a challenge is to make more of their proteins digestible. That is something that we are aiming to solve.”
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Protein minus meat
Change in food production is under way across the globe. Bloomberg Intelligence estimates the plant-based protein market will be valued at more than US$162 billion by 2029, up from US$29.4 billion in 2020.
The development of alternative proteins is also attracting government attention in Australia, with the New South Wales Government’s Tech Central Research and Innovation Infrastructure Fund granting $2.2 million to the University of Sydney’s Alternative Protein Application Centre (APAC).
One of the key challenges in developing plant-based protein is ensuring that it delivers on taste as well as texture.
However, Dehghani, who is also the co-lead of APAC, said solving this challenge can come at a cost to nutritional value.
“Nutrition is often placed third in the list of priorities, after taste and texture,” she said.
“Most of the alternative meat in the market also comes from soy, but it’s not a major source of legume or pulse produced in Australia.”
CAFE is currently working on a project to convert Australian-based pulses, such as peas, into protein-rich foods.
It’s also seeking to make more plant proteins digestible through methods such as enzymatic hydrolysis, a chemical digestion process that breaks down complex molecules within food.
“We’re also looking at other cost-effective methods like enzymatic fermentation to make plant-based proteins more digestible,” said Dehghani.
“Proteins are amazing molecules. The way that they combine to make strong textures and structures — it’s like an art form. We need to bring engineers and scientists together to look at how we can fold the proteins together.”
Cultivating the future
One of the most innovative — and ambitious — alternatives to meat-based proteins involves “cellular agriculture”, which produces animal proteins through processes such as microbial precision fermentation and the cultivation of animal cells in a lab.
Microbial precision fermentation uses synthetic biology techniques to engineer single-celled organisms that produce proteins that can be made into food products.
Dehghani describes the process as similar to brewing beer.
“Fermentation facilities already exist, but we’d need to change the production from beer to protein.”
Cultured meat is another type of cellular agriculture that involves cultivating animal cells in a lab to replicate the sensory and nutritional profiles of conventional meat.
The process involves feeding cells with an oxygen-rich culture medium consisting of nutrients such as amino acids, glucose vitamins and inorganic salts, supplemented with proteins and other growth factors.
“The cells from animals are very fragile compared with bacteria,” said Dehghani.
“They require a specific environment to grow, and you need to add some growth factors, antibiotics and other things to keep them alive.
“There are so many concerns about cultured meat that need to be overcome, such as how to get rid of the growth factor and how to make it more cost-effective compared with other sources of the protein.”
Engineering the menu
With the requirement for secure and sustainable sources of protein increasing, research is under way to develop protein alternatives from cultivated insect cells.
“The level of protein from insects is comparable with that from beef livestock, but the fat level is much lower, so it’s actually healthier,” said Dehghani.
“The level of iron is also much higher. Of course, many people are sceptical about using insects as a source of protein, but there’s a lot of research into using insect cells, rather than actual insects, to produce protein.”
What’s more, Dehghani added, the cultivation of insect cells may be easier than producing protein from other animal cells.
“Unlike mammalian cells from livestock, insect cells don’t need to be grown under a controlled condition of 37°C, which makes it more cost-effective, and they don’t need CO2 to grow. They are also resilient to pH change, and they require less nutrients.
“Insect cells are already used for the production of vaccines worldwide, but they can certainly be used to produce protein and to mimic the fatty taste that many consumers enjoy from meat.”
Engineers play a vital role in solving the challenges of sustainable protein sources and shaping the future of food, she said.
“The global population is growing, and the consumption of meat is actually growing even faster,” Dehghani added.
“We need more water and soil to produce meat from beef, pork or poultry — and there are limitations to the use of land. We need to develop more alternative, nutritious forms of protein for the future. It’s a growing area that requires the attention of more engineers.”