Lending muscle to artificial meat production

On the menu at The Restaurant at the End of the Universe, Douglas Adams’ ultimate eatery in the Hitchhiker’s Guide to the Galaxy stories, a living bovine offers its choicest cuts to diners. Whether or not the late Adams was taking a shot at vegetarian ethics we shall never know, but the concept of guilt-free meat is perhaps at the heart of research into growing meat-like materials in the laboratory.

NASA has developed technology to produce small gobbets of edible meat protein in the laboratory-and who could forget the artificial meats produced by microbial fungi and used in so-called “vegetarian meat pies”? Such efforts almost always suffer from the fact that the human palate is rather sensitive to foods that are genuinely meaty with the right texture and bite and those from sources far from the barnyard or cattle station.

Now, Pieter Edelman of Wageningen University, in The Netherlands, Douglas McFarland of South Dakota State University, Vladimir Mironov, of the Medical University of South Carolina, and Jason Matheny of the University of Maryland propose in the journal, Tissue Engineering, two new techniques that could one day lead to affordable production of lab, or factory, grown meat that tastes and feels just like the real thing, but, without the need for slaughterhouse nor butcher.

The research represents what the team describes as the first peer-reviewed discussion of the prospects for industrial production of cultured meat. “There would be a lot of benefits from cultured meat,” says Matheny, who studies agricultural economics and public health. “For one thing, you could control the nutrients. For example, most meats are high in the fatty acid Omega 6, which can cause high cholesterol and other health problems. With ‘in vitro meat’, you could replace that with Omega 3, which is a healthy fat.”

Cows by David BradleyThe idea of culturing meat is to create an edible product that tastes like cuts of beef, poultry, pork, lamb, or fish and has the nutrients and texture of meat. Matheny adds that cultured meat could be less energy intensive than livestock farming, produce less pollution, and could be less vulnerable to disease and bioterrorism, as it can be produced in sterile, highly secure facilities.

The efforts of other scientists demonstrated that single muscle cells from cows or chickens could be isolated and made to divide into thousands of new muscle cells. NASA research showed that fish tissue too could be cultured in vitro with the aim of developing putative food products for long-term space travel, where storage is a problem. “That was a single experiment and was geared toward a special situation,” Matheny says. “We need a different approach for large-scale production.”

The researchers have now developed ideas for two techniques that have potential for large-scale meat production. One is to grow the cells in large, flat sheets on thin membranes. The sheets of meat would be grown and stretched, then removed from the membranes and stacked on top of one another to produce a suitably thick layer of “meat”. The second method would be to grow the muscle cells on small three-dimensional beads that stretch with small changes in temperature. The mature cells could then be harvested and turned into a processed meat, like nuggets or hamburgers.

To grow meat on a large scale, however, would require cells from several different kinds of tissue, including muscle and fat to endow the meat with an appealing texture. “The challenge is getting the texture right,” adds Matheny. “We have to figure out how to ‘exercise’ the muscle cells. For the right texture, you have to stretch the tissue, like a live animal would.” The researchers explain that the idea of artificial, cultured, meat might not immediately appeal to consumers. However, ethical vegetarians and those after a potentially more healthy alternative might be readily persuaded.

“Cultured meat could appeal to people concerned about food safety, the environment, and animal welfare,” adds Matheny, “and people who want to tailor food to their individual tastes.” The researchers suggest that a meat maker might one day sit next to the breadmaker and microwave oven on the kitchen counter.

MironovUltimately, the benefits of in vitro meat could be enormous. The demand for meat is increasing worldwide, with China’s meat consumption set to double in the next ten years, while poultry consumption in India has doubled in the last five years. Such increased demand for meat could be accommodated in many parts of the world by factory production of artificial meat. “With a single cell, you could theoretically produce the world’s annual meat supply,” Matheny says. “And, you could do it in a way that’s better for the environment and human health. In the long term, this is a very feasible idea.”

“We don’t really know what the nutritional properties of this meat will be or how it will taste,” Metheny told Reactive Reports. “The protein content will depend on how thoroughly the muscles are exercised, as use enlarges the muscle fibers. By co-culturing muscle cells with fat cell types one could conceivably control the ratio of omega-3/omega-6 fatty acids. Some nutrients (like iron) are found in all muscle tissue; others (like vitamin B12) would need to be supplemented because they are products of digestion missing in vitro,” he adds.