Bread, beer, wine, yogurt, cheese… And now meat? Man-made fermentation, the first trace of which dates back to 14,000 years ago, is now being used for “meat without animals”. More precisely, the “precision fermentation” that renews, with the most advanced biology, the “old” fermentation technique – that natural ability of microbes to destroy carbon compounds like sugar in order to feed and multiply and, in doing so, , generate products (such as lactic acid or alcohol) that man has learned to use to his advantage. The aim of this combination of the modern and the ancient: to produce “compounds” of meat, animal proteins indistinguishable from any other animal proteins.
These will be used to add cultured meat or plant-based substitutes to improve its texture, color and flavor so that it resembles as closely as possible what the consumer expects from meat. In the case of precision fermentation, thanks to genetics, single-celled organisms (microbes) are specially designed in the laboratory to produce the specific compounds that are desired (animal proteins, etc.).
The concept is on the rise. Now, 39 companies have been launched in the world, including 15 founded last year. “The protein needs are there and the technology is mature: the cost of genome sequencing or DNA synthesis hitherto used for drugs – such as insulin which is made with precision fermentation – has dropped to the point where we can afford to of using it for food,” explains biologist Elsa Lauwers, scientific director at Paleo, a start-up based in Flemish Brabant whose laboratory is located in Gosselies and which focuses on animal proteins called “hemes”. The objective is, in fact, not to provide a complete steak as a final product by precision fermentation, which would be very complex, since the meat contains dozens and dozens of proteins, not to mention fats: “If it is the desired final product, it is better to resort to cultured meat. On the other hand, precision fermentation is really advantageous for producing a small number of ingredients, in large quantities, quickly and at low cost. There are several types of solutions, depending on the protein categories. Some have a structuring role in meat: companies manufacture collagen, for the time being applied to beverages. One can imagine adding proteins produced by precision fermentation as a kind of booster to cultured meat if it is found to be too soft. Additionally, fats are extremely important for flavor but also texture, and plant-based alternatives are often criticized for being a bit dry.”
The company Nourish Ingredients, for example, manufactures fats by precision fermentation and collaborates with Vow, for cultured meats based on animal cells enriched with animal fats produced by microbes. Among other such hybrid solutions, the famous Californian company Impossible Foods has added a plant-based heme protein to plant-based substitutes such as the Impossible Burger, which has been on sale in the United States since 2016.
Soy, tofu, tempeh, pea protein…
These heme proteins, which Paleo is also producing, occur naturally in fish and meat (animal muscles), up to about 10% of the protein content. A source of dietary iron, they give the meat its typical reddish-brown color and contribute to the particular flavor of meat and fish. “The idea is to really mimic meat in terms of taste and smell sensations, color and iron intake identical to meat. Based on the types of heme proteins, it tries to mimic the different types of meat that people are used to tasting. We also plan to take care of the texture, with other proteins, but nothing concrete at the moment”, specifies Elsa Lauwers. Specifically, these proteins would be added, in powder or liquid form, to recipes for vegetable substitutes: soy, tofu, tempeh, pea proteins… “We are focusing on products that already try to imitate meat, but not 100% there. Even if you add a lot of heme protein to a spinach burger, it will still be green! Soy, on the other hand, is quite neutral in flavor and color. When adding heme protein, it turns red when raw. And, above all, when cooked, it turns brown, a little caramelized… It would be possible to add beet juice, but after cooking it would turn red, which would not have the same satisfying effect for the consumer. For now, plant-replacement manufacturers are not happy with how they look after cooking.”
As for the taste, reproducing that of meat with traditional additives is very complicated, explains Elsa Lauwers. “Only animal protein can do that. One of our studies also showed that when we add our heme proteins to a veggie burger, it generates the (aromatic) molecules normally found in meat. We can therefore recreate the taste and smell of meat using these proteins. We also perform mass spectrometer analysis of our proteins: it is impossible to see the difference between our protein and a protein that would have been extracted from a steak. Cultured meat or what is produced by precision fermentation is therefore identical to real products, conventional meats, while substitutes can mimic meat but will never have exactly the same nutrients. Cultured meat, on the other hand, is the entire product and muscle components of beef or chicken, while precision fermentation produces just one or a few of the meat ingredients.”
How does this work exactly? The catalog of proteins that a cell can produce, be it a microbe like yeast or a cell in our body, is defined by the genome. “We know the code of every protein that we might be interested in producing. So it’s quite simple to design the DNA molecule that corresponds to that protein, introduce it into a microbe, and encourage it to manufacture that protein as if it were its own. Basically, we took yeast cells and introduced the DNA code for heme proteins from different types of animals. We add to the DNA codes a short DNA sequence, a signal peptide. Its role is to ensure that when the new protein is produced in the microbe, that protein is exported. This greatly simplifies the recovery process. There is no need to break cells down to get a new protein, mixed with thousands of other proteins and DNA. All we have to do is take the fermented medium, remove the cells and concentrate the rest. Cells and DNA are completely removed during protein recovery.”
This detail is really important: “it means that, according to the rules of the United States and the EU, the final product is non-GMO and does not contain modified DNA”, underlines the biologist. This will be important for consumer authorization and acceptance, at least in Europe. Clearly, the end product that would be introduced into food is not a genetically modified organism. The organism used to make the protein is in fact a GMO, but it is grown in a confined way, in steel tanks that are sterilized. The process is similar to what the pharmaceutical and beer industry does.” At this stage, Paleo has designed a series of heme proteins and is refining its production process on a larger scale, in a pilot plant. The approval process on the European market is expected to take two years. “To be profitable, you need 100,000 liter fermenters. In the sector, we will have to invest a lot in factories and production capacity”, warns Elsa Lauwers.
Sustainable and healthy?
And the sustainability of this production exactly? “It’s a very efficient and energy efficient process, especially compared to traditional livestock farming,” says Elsa Lauwers. In addition to cells, we must add sources of carbon, nitrogen and oxygen, water and energy. This energy is mainly used to stir the contents of the fermenter and cool it down. But the organic by-products of the process can also be used (for animal feed, fertilizing fields, etc.) and the water can be recycled. In terms of time, we are talking about a process that takes between one and two weeks, depending on the complexity of the recovery, compared to the months or years it takes to generate a conventional animal protein. In terms of nutrient efficiency – the efficiency with which the nutrients you supply are converted into a food product – for a fully optimized fermentation process, we can achieve up to 80% conversion from raw material to final product, which is very high. The environmental footprint of precision fermentation is very favorable compared to traditional means. In terms of land use and water use, we see a reduction of around 90%. For greenhouse gas emissions, a 70% reduction is a conservative estimate. But in reality, some microbial species are able to use CO2 as a carbon source. These processes can therefore have a negative carbon footprint. Not to mention the 100% reduction in animal exploitation.”
Does this type of offer combined with cultivated meat intend to replace conventional agriculture? “As other participants at the symposium (organized by the association for the defense of animals Gaia on April 25 on the topic of cultured meat NdlR) said, the idea is to increase the production supply but without increasing it. the impact of having more different production systems, replies Elsa Lauwers. The vocation is not to replace one or the other, to oppose vegans and carnivores. But there are many countries on the planet where the daily protein intake is below the WHO recommended intake. The advantage of fermentation is that where you can make beer, you can make precision fermentation. One can imagine the production of proteins in areas quite unsuitable for agriculture or in urban environments. It would be “sufficient” to install fermenters and the amount of water and soil needed is much less.”
However, consumers still seem to have reservations, particularly in terms of health risks, according to marketing studies: “I understand the fears. Because it’s new, it’s always scary. But whether it’s cultured meat or precision fermentation, in terms of the finished product you eat, you’re talking about a product identical to meat, except it’s more controlled. What happens to an animal that is grown in a factory and then slaughtered is far more complex than what happens in a fermenter you can control. There is no risk of parasites. We are much closer to drug manufacturing methods, which are still much more controlled than traditional agriculture.”