The meat we know and eat is essentially the body parts of slaughtered animals. An animal is created from a single fertilized cell (zygote). The same cell undergoes divisions, differentiation and enlargement until the organs that comprise an entire creature are created. The idea of cultured meat is to grow the animal organs we eat directly from original cells, instead of creating whole creatures and only then, producing the meat we eat from them. This way we can take cells and let them divide naturally, differentiate, grow larger and turn into the tissues we eat (mainly muscle and fat), and in this fashion create an economic, green and humane process.
At the current research state, cultured meat is created by taking satellite cells from a live animal with a non-invasive and painless procedure. Scientists nourish the cells and let them divide naturally. A single satellite cell divides to create roughly (10^18)1,000,000,000,000,000,000 adult muscle cells.
In the future, as research advances, we will be able to create a cell reservoir that could, in principal, serve us perpetually and would not necessitate the use of animals. These cells are pluripotent stem cells. These cells, (for example embryonic stem cells and iPSC) are cells with the ability to divide eternally and can develop into many different types of cells, and therefore create an array of different tissues. Theoretically, one stem cell is enough to supply the entire global demand for meat. The stem cells are nourished with different substances and are left to divide and remain undifferentiated. When there is a demand for a certain type of meat, some cells are taken from the reservoir and they are turned into fat or muscle cells, and that's how you get meat.
Creating the appropriate muscle tissue
One way is to sow the cells on scaffolds made of proteins, sugars and/or other natural polymers which give the scaffold properties that facilitate cell growing and the creation of tissue. Muscle cells grow and divide on the scaffold and merge into muscle strands. In order to make the muscle strands meaty, the scaffold is stretched in a periodic fashion, a process that promotes the creation of muscle tissue.
An innovative way developed by Professor Mark Post's research team, allows for minimal intervention and reliance on the natural process of muscle creation. When muscle cells are left to divide naturally and they reach critical density, they start merging naturally with short muscle strands. In order to turn these muscle strands into meaty muscle tissue, the strands are placed around a hard pole of gel and are covered in a soft and nutritious gel full of protein. The muscle strands create the structure of a ring around the pole and spontaneously press on it. The tension created makes the muscle cells mature and meatier and allows the creation of muscle tissue.
For further reading:
- Post MJ "Cultured beef: medical technology to produce food", J Sci Food Agric (2013)
- Post MJ “Cultured meat from stem cells: challenges and prospects”, Meat Sci. (2012)