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Dr Karl: Future food, ethics and sustainability via hamburgers

31 March 2023
Food is complicated – and not particularly sustainable.
Complicated? What is not in strawberry yoghurt – cow’s hooves, seaweed or strawberry?

Yup, strawberry! The strawberry flavour comes from industrial chemistry. The hooves provide gelatin (giving a gel-like consistency), while the seaweed delivers carrageenans (which thicken the 'product', to improve the 'mouth-feel').

Sustainability? While meat provides about 15% of the energy in the food that we humans eat, it takes up about 80% of our agricultural land.

Dr Karl Kruszelnicki

Dr Karl Kruszelnicki

Secondly, beef is inefficient in terms of how much protein you get from each hectare of that farmland. For example, pork gives you four times as much protein as beef, while poultry and fish provides 12-14 times as much and insects give you 30 times more. But plants outrank all of them, giving you at least 50 times more protein than beef per hectare.

But consider greenhouse gas production - kilograms of carbon dioxide produced, for each kilogram of protein. Traditional beef emits 130 kg of greenhouse gases for each kilogram of beef on your barbecue, while so-called 'modern' beef is 40 kg. Pork comes in at around 10 kg, while each kilogram of chicken costs us 5 kg of greenhouse gases. But protein from plants and from insects is around 2-3 kg– very different from 130 kg.

Currrently, livestock is responsible for a whopping 40% more greenhouse gas emissions than the entire worldwide transport sector – that’s all motor vehicles, ships, planes and trains combined.

Finally, health concerns are associated with too much meat - and not just for our own personal health. Meat industries are increasing antibiotic resistance in bacteria, and can lead to the transfer of diseases from animals to humans.

So why has meat remained popular, despite its problems? Well, from a nutrition point of view, it’s loaded. It has heaps of easily digestible protein with all the amino acids you need, as well as vitamin B12, and lots of minerals including iron – and the fantastic taste.

It tuns out that the haemoglobin chemical in meat provides much of that meaty flavour. Surprisingly, a similar chemical, leghaemoglobin, exists in some plants – such as soy beans. Add some clever chemistry and you’ve got a plant burger that tastes like a meat burger.

But 'tissue engineering' can make real meat burgers, without a living animal!

This meat is genuinely meat, but it comes from stainless steel vats. You start with a single cell, turn on the parts of the DNA that make muscle and blood, and with a lot of clever science, you end up with meat grown entirely in a factory. It was expensive, but the price is dropping very rapidly.

We’re finding more sophisticated ways to eat more sustainably, thanks to clever science.

Written by Dr Karl Kruszelnicki, the Julius Sumner Miller Fellow at the University of Sydney.