While cattle-free quarter-pounders or chicken-free nuggets may sound like science fiction, Jason Matheny, lead author of a paper on in vitro meat production in a June 2006 issue of the scientific journal Tissue Engineering, says it's closer than you think. In fact, the University of Maryland graduate student says researchers in the Netherlands and the U.S. expect to perfect a scalable process to produce cost-effective, in vitro (lab-grown), processed meats within five years.
Matheny says the technology isn't new. Medical researchers have long been able to grow muscle tissue in the lab. Factory-grown meat just adapts this technology to industrial-scale meat production. Matheny says it's a logical extension of technology-driven agriculture.
Douglas McFarland, a South Dakota State University animal science professor and co-author, says cattlemen needn't worry about competition from in vitro meat anytime soon.
“I don't imagine I'll be buying a slab of tissue-engineered meat in the supermarket in my lifetime,” McFarland says. “It will remain too expensive, and I don't know if enough money is going to be put into it (research) to make it a reality.”
McFarland believes in vitro technology will first be used for specialty applications, such as supplying astronauts with meat on long space flights.
How it's done
The first step to growing muscle tissue in the lab is to harvest satellite cells — precursors to muscle cells — from a cow using a biopsy. The cells are then put into a vat of “nutritious soup,” Matheny says.
“Over a period of days, the cells divide into millions of daughter cells, just like the original. These are poured onto a sheet with thin grooves in it, which is placed in a bioreactor to grow.”
Muscle cells need to be stretched to grow and develop properly. If not, they have a texture closer to cooked oatmeal than meat. The simplest way to simulate exercise is by flexing the sheets the cells are grown on. Just flexing the sheets by 10% every few minutes is enough to cause the cells to align and fuse into myofibers. Eventually, over a couple of weeks, you have a thin layer of muscle tissue.
Current technology only allows the growth of very thin layers of tissue, which would be suitable for grinding into such traditionally processed meats as hamburger, sausage, chicken nuggets or fish sticks. While current technology could produce a product with an identical flavor and texture to existing processed meats, it's nowhere close to being able to produce a steak. To grow large, three-dimensional pieces of tissue, it's necessary to grow blood vessels to supply nutrients to interior cells.
Lowering cost is the key
“In biomedical tissue engineering, the skeletal muscle is produced in very small portions — square centimeters instead of square meters — at a high cost,” Matheny says.
A large part of that cost is the growing medium, calf serum. In vitro meat research currently is focused on finding ways to do this cheaper. In fact, research in the Netherlands has narrowed the search to media made from four varieties of mushrooms.
If suitable growing media are perfected, Matheny says factory-grown meat could compete with meat from animals. After all, farm animals, due to maintenance requirements, convert little of what they're fed into what we ultimately eat. In vitro meat would have no waste, bones or offal to dispose.
Matheny says a lot of inefficiencies are introduced into meat processing because, “farm animals are simply the wrong shape.” Most meat processing involves changing the shape of farm animals into cuts that can be consumed. Producing meat by the square yard eliminates most of the costs associated with processing live animals.
“We've managed to make meat production much more efficient in terms of labor, but it wouldn't be as efficient as just one person pushing a button on an enormous incubator,” Matheny says. “There are also inefficiencies caused by meat production's unpredictable nature — the problems caused by biology and weather. It would be much more efficient economically if we found a way to decrease all that variability and bring the whole thing into a controlled setting.”
Other advantages
At first glance, all the effort being put into developing in vitro meat seems as pointless as re-inventing the wheel. After all, Mother Nature has already provided us with cattle, hogs and chicken.
“Control is the main advantage,” Matheny says. “While we've gotten pretty good at controlling marbling in live animals, it could be done much more accurately in vitro. We could precisely control how much fat there is, its location, even the ratio of omega 3 to omega 6 fatty acids.
“Because you could produce ground beef with the fat profile of salmon, in vitro meat could satisfy a consumer's interests in healthier meats. Consumers' concerns about fat and cholesterol could be addressed in a way we can't with live animals,” he adds.
Producing the meat supply in a highly secure, sterile environment, such as a pharmaceutical bioreactor, also would dramatically lower the risk of bacterial contamination or disease. It would be easier to protect a few meat factories from bioterrorism than a national herd spread over 600 million acres. In the Netherlands, where most research on in vitro meat is centered, it's driven by the need to reduce intensive livestock farming's environmental impact.
Will consumers accept it?
People already love hot dogs, sausages and other processed meats made from stray protein of indeterminate origin, Matheny says. And many consumers prefer not to consider the origin of their meat. Many would be quite happy to learn their chicken grew on a styrofoam tray, wrapped in cellophane.
“Consumers don't really have a sense of how meat is produced,” Matheny says. “They see the end product, which often bears no resemblance to the animal. What they care about is how the product tastes and whether it's affordable. When people ask me if consumers will accept this kind of meat, I think, ‘yes, look at what they already accept.’”
If in vitro meat production ever becomes reality, Matheny says it will offer economic incentives to most everyone in the meat-production chain, except those currently growing animals.
“But the adoption of this technology would be so gradual, it would be just a continuation of the current trend in ag,” Matheny says. “In the early part of this century, a quarter of all Americans were employed on farms. Today, it's around 1%.
“It's not like the other 24% are unemployed; their kids just did something else. In this case, perhaps the future farmers of America are microbiologists rather than cattle ranchers,” he says.
Lorne McClinton is a freelance writer based in Yellow Grass, Saskatchewan, Canada.
