Lab-grown meat could get a flavour boost thanks to aromatic chemicals that activate when cooked, releasing a meaty smell – or if you prefer, that of coffee or potatoes.

Meat grown from cultured cells can already be created in various forms that resemble slaughtered meat, including steak and meatballs, but matching the taste has proven more challenging. Traditional meat flavours are extremely complex and volatile and don’t survive the lengthy laboratory process.

One key component of the taste of cooked meat is the Maillard reaction, named after a French chemist who discovered that unique flavours are created in cooked food at between 140 and 165°C (280 to 330 °F). at Yonsei University in Seoul, South Korea, and his colleagues say they have worked out a way to simulate the Maillard reaction by adding “switchable flavour compounds” (SFCs) into a 3D gelatine-based hydrogel, called a scaffold, that remain stable while the meat is cultured.

Once heated to 150°C, the chemicals “switch on” and release their flavours, improving the cultured protein’s palatability. “We actually smelled the meaty flavour upon heating the SFCs,” says Hong, though he wouldn’t confirm whether the team had actually eaten the meat.

These SFCs can also be used to create different flavour profiles. For example, the researchers tested three compounds and say they produced flavours simulating roasted meat, coffee, roasted nuts, onions and potatoes. “We can diversify and customise the flavour compounds released from the SFC,” says Hong.

One big issue is that the chemicals involved aren’t currently seen as safe for human consumption. “Because the materials and culture medium are not approved as edible materials, we cannot ensure the safety of it,” Hong says. “However, we think that our strategy can also be applied to conventional edible materials, which would be safer than the materials used in this study.”

at the University of New South Wales in Sydney, Australia, says he is sceptical of the work for numerous reasons, including that the flavour tests predominantly used an electronic nose to assess the chemicals being released, rather than human judgement of whether they smelled appetising.

“You cannot nourish human beings with this type of material,” says le Coutre. “While cell-based meat is a promising technology concept, this particular way of adding flavour will never provide safe and sustainable protein for low and middle-income communities that need food.”

Researchers have engineered cows’ muscle cells that can multiply without the assistance of an expensive and energy-intensive growth-boosting substance. If scaled up, they are optimistic this could slash the production costs of lab-grown meat, but they stress that it is still early days.

Lab-grown, or cultivated, meat can be produced from animal cells. Approved for sale in countries such as the US and the Netherlands, it has been touted as a more ethical and sustainable substitute to conventional meat, by avoiding the slaughter of animals and using fewer resources, such as water.

But the current, small-scale methods of producing lab-grown meat have still proven to be extremely energy intensive and expensive.

To grow cells outside an animal, they must be cultivated in a cell culture medium, a mixture of nutrients and growth factors. The latter latch onto receptors on the surface of animal cells and tell them to grow and differentiate, making them a crucial part of the mixture, says at Tufts University in Massachusetts.

Currently, these make up around 90 per cent of the cost of lab-grown meat production, so Stout and his colleagues wanted to come up with an alternative approach.

They first built small DNA molecules called plasmids that contained genes with instructions for cells to produce their own growth factors for fibroblasts, cells that help to form connective tissues.

The researchers then inserted these plasmids into cows’ muscle cells, finding that they differentiated into skeletal muscle cells, common components of steaks and beef burgers, that grew and multiplied.

Although the researchers only experimented with cow cells, they think the technique will also work on cells from other animals, such as chickens and pigs. They hope these engineered cells could one day aid in expanding the scale and lowering the cost of cultivating lab-grown meat.

“Give a cell a fibroblast growth factor and it’ll grow for a day, but teach a cell to produce its own fibroblast growth factor and it’ll grow forever,” says Stout. “This is just a proof of concept, but it’s really exciting to think about how cells can be our allies in this endeavour and we can engineer them to help us.”

According to at Aston University in Birmingham, UK, “there is still a long way to go until lab-grown meat becomes a commodity, but every day we are getting a step closer to it”.

Issues that need to be overcome include the team’s cultivated meat growing slower than with conventional approaches, says Theodosiou. In addition, foods that contain genetically modified organisms, such as these plasmids, are only legal in some countries and there is still a widespread reluctance to eat them, she says.