Meat substitute: a realistic steak made from plant proteins

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For many, a perfectly cooked beef steak is the epitome of meat enjoyment. Roasted aromas in the crust, meat juices escaping from soft fibers and cooked fat combine on the tongue to create an irresistible taste experience. Despite all conviction, this often makes it difficult to give up. Hubertus Bessau even tried going completely vegan for several months. The poor carbon footprint of beef production and its contribution to the climate crisis had spurred the MyMuesli founder to give up meat.

"I failed because of the social environment and the fact that the main actor on the plate was often missing after all," Bessau says. "As a human being, you probably optimize for short-term happiness rather than the long-term benefit of the next generations." Together with mechanical engineer and materials scientist David Schmelzeisen, whom he met as an enthusiastic cook while sailing, and ex-Zalando manager Jan Wilmking, he nevertheless asked himself what would have to happen in order for many people to change their eating behavior more permanently and at least eat less meat.

Steaks and roasts from plant proteins

Their conclusion: This can only be achieved with meat substitutes that offer the same enjoyment as the original and, best of all, are even tastier. To do this, they also have to feel right when chewed. However, such meat textures have not yet been convincingly achieved by plant-based substitute products. Steaks or roasts made from plant proteins are rarely seen. Schmelzeisen and his team want to change that with their start-up "Project Eaden" and are working on a new production method to recreate the structure of unprocessed pieces of meat from pea and other plant proteins in a particularly realistic way.

Still, there are a handful of companies that are turning to 3D printing for the plant-based meat eating experience. Israeli startup Redefine Meat is already far along in this field. It entered the European restaurant market in 2021 with its plant-based products. Redefine Meat has its products created in specially designed industrial 3D printers. Texture, taste and eating experience should thus be the same as with beef and other high-quality meat, the company explains, promising 95 percent less environmental impact. For the year 2022, Redefine assumed a production of 15 tons per day.

Schmelzeisen and his colleagues also want to conquer this market with their start-up "Project Eden". However, they are working on a different production method to particularly realistically replicate the structure of unprocessed meat pieces from pea and other plant proteins.

Most meat substitute products are produced by extrusion, when plant protein masses of varying moisture are pressed through holes under high pressure, as in a pasta machine. This results in the formation of fibrous protein sponges, which are usually quite uniform and structureless. In the case of sausage and ground meat substitutes, this certainly suits the product. Fibrous chicken breast substitutes, on the other hand, tend to be the exception.

To produce fibrous plant-based beef steaks, Schmelzeisen took inspiration from a branch of industry that at first glance seems unusual for food production: spinning processes from textile manufacturing. However, the mechanical engineer had earned his doctorate in the field and had worked on how the characteristics of spun textiles can be specifically changed, for example, by the application of heat.

Fiber by fiber

He brought the knowledge gained from this to Project Eaden. The goal is to spin and align plant protein fibers in such a way that the composite has different mechanical properties in the longitudinal direction than in the transverse direction. This so-called anisotropy is also exhibited by real meat. This consists of muscle fibers, i.e. relatively soft proteins, which are surrounded by fine but firm collagen sheaths with high strength. These give structure to the composite. Several muscle fibers together form muscle bundles, which in turn are surrounded by connective tissue.

To achieve fiber sizes that are perceptible to the tongue, solvent and melt spinning processes are best suited, Schmelzeisen says. How the technology works in detail is a company secret. But Schmelzeisen shows early experimental videos with a red liquid from which fibers are pulled and wound into bundles. As another intermediate step, he also shows flat pieces of red plant flesh a few millimeters thick, consisting of several hundred bundled fibers. Meanwhile, incorporating vegetable fats, the company has produced marbled pieces of meat that look confusingly similar to their animal counterparts at first glance.

In order to produce such structures, the textile plants - which have also been adapted in terms of hygiene and cleanability - must be configured to produce protein fibers with corresponding properties. Quite similar to the way the plants are also adapted "if you want to produce an even more stretchable nylon fiber instead of a polyester one," says Schmelzeisen.

Tinkering with the taste of meat

While the meat structure is already quite advanced, the company is still working on the right meat flavor. This is intended to provide the right roast and meat juice aromas after roasting. Schmelzeisen wants to take into account the fact that we not only perceive taste via the tongue, but that a large part of it is actually scent perception - via the nose, but also via what is known as "retro-nasal tasting," which is basically a smelling process in the throat.

Previous spice blends were often optimized for ready-to-eat meat dishes. But "less broad" flavors are needed for plant steak, he said. Once the right blend is found, Schmelzeisen says the spices can be easily incorporated into or applied to the fibers during production, which provide a large surface area for them. A first tasting is planned for this year.

The adapted textile technologies have a second advantage. They are already extremely trimmed for efficiency and cheap production. This is not necessarily an advantage in the case of clothing, because cheap clothing is thrown away more quickly. However, Project Eaden hopes that the textile technologies will also make their products cheaper and thus more competitive.

Asked about the carbon footprint of their products, Bessau replies, "If you look at the high-energy, high-moisture extrusion processes, they're up to 95 percent lower compared to the emissions that beef produces," Bessau says. "We haven't been able to calculate and measure through everything yet. But we strongly expect to be in that range as well."

(vsz)