What if the next burger you ate was created in a warm, nutrient-enriched soup swirling within a bioreactor?

Edible, lab-grown ground chuck that smells and tastes just like the real thing might take a place next to Quorn at supermarkets in just a few years, thanks to some determined meat researchers. Scientists routinely grow small quantities of muscle cells in petri dishes for experiments, but now for the first time a concentrated effort is under way to mass-produce meat in this manner.

A sample of muscle grown without an artificial scaffold. (Photo: Wired / Tissue Genesis)

Henk Haagsman, a professor of meat sciences at Utrecht University, and his Dutch colleagues are working on growing artificial pork meat out of pig stem cells. They hope to grow a form of minced meat suitable for burgers, sausages and pizza toppings within the next few years.

Currently involved in identifying the type of stem cells that will multiply the most to create larger quantities of meat within a bioreactor, the team hopes to have concrete results by 2009. The 2 million euro ($2.5 million) Dutch-government-funded project began in April 2005. The work is one arm of a worldwide research effort focused on growing meat from cell cultures on an industrial scale.

"All of the technology exists today to make ground meat products in vitro," says Paul Kosnik, vice president of engineering at Tissue Genesis in Hawaii. Kosnik is growing scaffold-free, self-assembled muscle. "We believe the goal of a processed meat product is attainable in the next five years if funding is available and the R&D is pursued aggressively."

A single cell could theoretically produce enough meat to feed the world's population for a year. But the challenge lies in figuring out how to grow it on a large scale. Jason Matheny, a University of Maryland doctoral student and a director of New Harvest, a nonprofit organization that funds research on in vitro meat, believes the easiest way to create edible tissue is to grow "meat sheets," which are layers of animal muscle and fat cells stretched out over large flat sheets made of either edible or removable material. The meat can then be ground up or stacked or rolled to get a thicker cut.

"You'd need a bunch of industrial-size bioreactors," says Matheny. "One to produce the growth media, one to produce cells, and one that produces the meat sheets. The whole operation could be under one roof."

The advantage, he says, is you avoid the inefficiencies and bottlenecks of conventional meat production. No more feed grain production and processing, breeders, hatcheries, grow-out, slaughter or processing facilities.

"To produce the meat we eat now, 75 (percent) to 95 percent of what we feed an animal is lost because of metabolism and inedible structures like skeleton or neurological tissue," says Matheny. "With cultured meat, there's no body to support; you're only building the meat that eventually gets eaten."

The sheets would be less than 1 mm thick and take a few weeks to grow. But the real issue is the expense. If cultivated with nutrient solutions that are currently used for biomedical applications, the cost of producing one pound of in vitro meat runs anywhere from $1,000 to $10,000.

Matheny believes in vitro meat can compete with conventional meat by using nutrients from plant or fungal sources, which could bring the cost down to about $1 per pound.

If successful, artificially grown meat could be tailored to be far healthier than any type of farm-grown meat. It's possible to stuff if full of heart-friendly omega-3 fatty acids, adjust the protein or texture to suit individual taste preferences and screen it for food-borne diseases.

But will it really catch on? The Food and Drug Administration has already barred food products involving cloned animals from the market until their safety has been tested. There's also the yuck factor.

"Cultured meat isn't natural, but neither is yogurt," says Matheny. "And neither, for that matter, is most of the meat we eat. Cramming 10,000 chickens in a metal shed and dosing them full of antibiotics isn't natural. I view cultured meat like hydroponic vegetables. The end product is the same, but the process used to make it is different. Consumers accept hydroponic vegetables. Would they accept hydroponic meat?"

Taste is another unknown variable. Real meat is more than just cells; it has blood vessels, connective tissue, fat, etc. To get a similar arrangement of cells, lab-grown meat will have to be exercised and stretched the way a real live animal's flesh would.

Kosnik is working on a way to create muscle grown without scaffolds by culturing the right combination of cells in a 3-D environment with mechanical anchors so that the cells develop into long fibers similar to real muscle.

The technology to grow a juicy steak, however, is still a decade or so away. No one has yet figured out how to grow blood vessels within tissue.

"In the meantime, we can use existing technologies to satisfy the demand for ground meat, which is about half of the meat we eat (and a $127 billion global market)," says Matheny.

© Copyright 2006, Lycos, Inc.

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