In vitro meat
Every day thousands of animals get killed to feed a rapidly growing human population. The prevalent practices of 'slaughter to salver' entail risks of infection as also suffering for the animals. A new technology of producing animal meat in the lab could be the much awaited solution, Pawan Kumar Dhar contends.
doi:10.1038/nindia.2011.131 Published online 23 September 2011
Scientists have grown a soggy form of pork meat in the lab1.
The idea of growing chicken nuggets on a petri plate is not new. The emergence of in vitro meat science is an outcome of years of experience in the animal tissue culture. The big question is: can millions of cells be grown as meat with the shape, texture and flavour of the original thing? Will bloodless meat substitutes replace traditional meat?
Though several efforts are on at the experimental level, lab-cultured nuggets are not yet available for public consumption. Research is rapidly moving towards harvesting a chicken nugget and a meat sausage from a test tube. Culturing loose muscle cells is less cumbersome than culturing structured muscle cells. In theory, one could take stem cells and convert them into fully grown muscle cells. These muscle cells could then fuse into muscle fibers.
For culturing a nugget-grade muscle tissue, the cell growth should be confined to a three dimension arrangement, using a set of chemical cues in a quorum sensing like environment. To give it a final shape, muscle fibers should stick to each other and show enough malleability to form a nugget or a meat ball.
Non-animal culture medium
The key claim of in vitro meat scientists is the vegetarian nature of cultured meat. However, given that fetal bovine serum, prepared from unborn calf, is a key ingredient of the cell culture, it is difficult to justify that the process is purely vegetarian. Plant and milk sources are increasingly being projected as practical alternatives to animal serum. Once a vegetarian or a chemical soup gets established as a reasonable alternative to serum, it would truly revolutionize in vitro meat technology.
The argument in favour of in vitro meat technology is that culturing meat is safer and more ethical than conventional meat. Currently, it does not involve genetic modification of muscle cells. The production of lab meat eliminates the need to inject growth hormones in farm animals. Also, one could possibly grow low fat meat with expression of omega-3 fatty acids as an added health bonus. Over-consumption of animal fats, pollutants, harmful bacteria and bio-accumulation of environmental contaminants add to our health burden. The UN has attributed 18% of the world's greenhouse gases to livestock.
However, version 1 of lab-cultured meat is expected to be prohibitively expensive and probably may not taste like natural meat. Once the community accepts the technology-driven-synthesis of meat, the cost of culturing such meat might get competitive with traditional meat production. Muscle cells are cultured using serum, growth hormone and antibiotics, which if consumed by humans, may result in adverse health effects. One would need to assess the health risks of in vitro meat technology to fully understand the cost-to-benefit ratio.
In 2008, animal rights group PETA (People for the Ethical Treatment of Animals) offered a million dollar prize to make commercially viable quantities of in vitro meat by June 2012. However, nobody won the prize. The parameters were stringent i.e., to produce lab meat in bulk that has a texture and tastes like natural meat and to sell it at a competitive price in at least 10 states.
Another non-profit organization promoting the development of ethical meat technologies has constituted a prize for developing in vitro meat technology.
The Netherlands has also invested USD 5 million into in vitro meat feasibility studies.
The animal farming industry works on the agenda of maximizing profits from sale of animal meat and leather. More than 7 billion chickens and 42 million cows are killed for meat every year in the U.S. Besides being subjected to cruel and unhealthy conditions, many of them are exhausted with repeated cycles of artificial impregnation till their bodies wear out and they are killed for meat.
With rising global population and conventional meat production getting more expensive, these alternative food sources might turn into mainstream food sources in the coming decades. People have adopted imitation meat that originates from soyabean. It remains to be seen if lab-grown meat will be as popular.
From the environmental perspective, in vitro meat technology will produce lesser greenhouse gases than conventional meat processes.
The first version of lab grown meat would probably be sausages and nuggets. Making lab meat look like a natural chicken leg would be more challenging — involving complex tissue engineering to create three-dimensional growth of muscle fibers of various sizes, supported by an edible scaffold, e.g. collagen. One could add fat cells to muscle cell culture to give the taste of a meat. One may possibly need a strain of faster growing muscle cells for lowering cost of cultured meat. The in vitro meat technology would also be a boon for astronauts who can have fresh meat every week on their way to Mars!
- Langelaan, M. L. P. et al. Meet the new meat: tissue engineered skeletal muscle. Trends Food Sci. Tech. 21, 59-66 (2010)