Scientists aim for lab-grown meat
August 15, 2005 - 9:39AM
Researchers are dishing up the perfect conundrum for vegetarians - meat grown in a laboratory dish, not on the hoof.
While it may be years before you savour laboratory-raised meat from your backyard barbecue, researchers say the technology exists now to produce processed meats such as burgers and sausages, starting with cells taken from cow, chicken, pig, fish or other animal.
Growing meat without the animal would not only reduce the need for the animals - which often are kept in less than ideal conditions - meat production is also blamed for a variety of environmental ills.
Cultured meat could also be tailored to be healthier than farm-raised meat, while satisfying the increasing demand for protein by the world's growing population, proponents say.
Brian Ford, a British biologist and the author of The Future of Food, said the widespread acceptance of meat substitutes such as 'quorn', a cultured fungus, "shows that the time for cultured tissue is near".
Techniques for engineering muscle cells and other tissues were first developed for medical use, and now a small handful of researchers are looking into growing edible muscle cells, said Jason Matheny, a University of Maryland doctoral student who co-authored a paper on in vitro meat techniques.
Industrialising the process could involve growing muscle cells on large sheets or beads suspended in a growth medium.
The sheet would have to be stretched, or the beads would have to be expandable, to stretch the cells and provide the exercise, if you will, needed for the cells to develop, he said.
"If you didn't stretch them, you would be eating mush. It would be like pink-coloured Jello," Matheny said.
Once the cells have grown enough, they could be scraped off and packaged. If edible sheets or beads are used, all of it could be eaten.
"The technology is there to produce something like a processed meat, you could produce a heavily processed chicken meat just like, perhaps, a nugget," Matheny said.
"The technology to produce something like a steak or chicken breast is still quite a ways off, there's a lot of technological challenge to producing something that has a structure to it."
Growing a steak, for example, requires more than just muscle cells. Blood vessels, fat and connective tissue would also have to be grown.
If too many muscle cells grow on top of each other, for example, the cells on the inside of the muscle mass will no longer be exposed to the nutrients in the growth medium and will die, Matheny said.
In June, researchers at the Massachusetts Institute of Technology said they had taken a step toward solving that problem.
The researchers, studying the creation of replacement parts for humans, said they used a mix of cells to grow muscle tissue that had its own blood vessels.
The human tissue was implanted into mice where they watched blood flow into the engineered muscle.
Touro College bioengineer Morris Benjaminson said fish muscle cells cultured at his laboratory for NASA passed a "sniff panel", and he believes seafood might be the first to be laboratory cultured.
"We actually did cook the fish meat we grew," Benjaminson said.
"It looked, according to them, and smelled like the fish you can buy in the supermarket."
However, the panel did not eat the cultured meat, he said.
While growing meat in a dish is currently too expensive for anything but space travel, Benjaminson thinks it is feasible to one day produce a cheaper, tastier, fishless-stick.
"With a little bit of money and time we could produce probably something that resembles a fish filet," he said.
"There's no reason to think it would be just as flaky as any other fish filet."
Crab, shrimp or other shellfish also could be cultured, he said.
Dr Vladimir Mironov, director of the Shared Tissue Engineering Lab at the Medical University of South Carolina, envisions a countertop device like a bread machine could one day produce sausage or hamburger.
Instead of flour, water and yeast, it would need muscle stem cells, a growth medium, and an edible structure for the cells to grow on, he said.
While Benjaminson's research required the fish to be killed to get the muscle cells needed to start the process, eventually the process could be refined to allow the use of a cultured cell line or a biopsy so the donor fish could live, he said.
While many growth mediums are animal based, Benjaminson said he has also developed a mushroom-based growth medium.
Researchers at South Dakota State University have also developed an animal-free medium, Matheny said.
If a product is brought to market, Matheny admits he is not sure how consumers would react.
"In some ways, this is a product of biotechnology in the same way bread and wine and cheese are products of biotechnology," Matheny said.
"You take something that's found in nature, and reproduce it in a controlled environment."
How regulators might react is also not known. The US Food and Drug Administration, for example, has asked companies that clone animals not to market any products involving cloned animals until the safety of the products has been evaluated.
Ford said many are already turned off by meat because of the miserable lives many animals suffer.
Cultured meat could appeal to those consumers, but it is not likely to appear in stores soon.
"People will take time to get used to the idea, and it will be a slow process of adaptation," Ford said.
Pitfalls include viruses that could infect meat cultures, he said.
If the idea is rushed to market before it is shown to be safe, the public will be turned against the concept.
"That's what has already happened with genetically modified crops," Ford said.
"The idea of cultured meat has great appeal to me, but we must move cautiously."
