Proteins are among the fundamental biomolecules that we need in our diet, as all our cells contain them. Amino acids are the units that make up proteins and there are twenty different ones, of which we highlight the essential ones because they are those that the body cannot produce and, therefore, have to be provided by the diet. Here is a list of these essential amino acids: leucine, isoleucine, valine, methionine, lysine, phenylalanine, tryptophan, threonine, histidine and arginine.
Proteins are among the fundamental biomolecules we need in our diet, as all our cells contain them. Amino acids are the units that make up proteins, and there are twenty different ones. Especially important are essential amino acids, called this way because our body cannot produce them, and we must ingest them. These are the ten amino acids indispensable for the human diet: leucine, isoleucine, valine, methionine, lysine, phenylalanine, tryptophan, threonine, histidine and arginine.
The protein sources in our diet can be classified according to their origin:
- Animal: meat, eggs, fish, and milk.
- Plant: pulses, cereals, seaweed, nuts and seeds
What is the problem? Currently, most of the population consumes animal protein, a trend with a high environmental impact, especially when compared to plant protein. Environmental impact consists of high levels of greenhouse gas emissions and water consumption, and a large proportion of land taken up by intensive livestock farming.
IS IN VITRO MEAT, AN OPTION FOR THE FUTURE?
Synthetic, artificial, in vitro, or cultured meat are foods made in laboratories from stem cells extracted from animal muscles. Together with other essential elements and under ideal conditions, stem cells allow new muscle tissue to be obtained. The idea is to replicate tissue from a living organism in the laboratory by extracting cells from that organism.
What are cell culture and tissue engineering?
Cell culture is the growth of microorganisms such as bacteria, fungi, or animal or plant cells in the laboratory. Tissue engineering, on the other hand, is the discipline of creating functional tissues from materials, cells and molecules.
These disciplines were first applied in the healthcare field, such as for the production of blood cells for use in immunosuppressed patients.
Source: The Food Tech
In vitro meat procedure
First of all, muscle tissue is extracted from an animal. It contains different cell types, but it must include stem cells. These are special because they can successively replicate themselves and differentiate into different cell types. To understand this fact, we will use the following metaphor: suppose you have a blank book (stem cells); then, depending on what you write on its pages (genetic expression), you will have a novel, a comic book, etc. In other words, stem cells can produce different cell types, such as cardiac muscle cells, bone cells, or neurons. We can say that stem cells have not yet decided what they want to be.
If stem cells receive the necessary nutrients and stimuli, they will be able to replicate (multiply). In addition, and depending on the stimuli, some signals or others will be sent, resulting in stem cells differentiating into muscle and adipose (fat) cells, in the case of synthetic meat.
This procedure attempts to replicate a particular type of tissue, and every tissue has a specific structure and characteristic properties, its cells having a certain amount of cohesion and tension. Structure (the shape of meat) has proven to be a limiting step in the lab because of the extreme difficulties in replicating the three-dimensionality of the tissue in the absence of the interwoven thin capillaries that characterise natural muscle. It is why we can make meatballs or burgers but still not steaks.
Let’s look at a general outline of the laboratory protocol:
- Extraction of muscle tissue from an animal, e.g. a chicken or a cow.
- The extracted tissue is placed on a Petri dish and mechanically cut into smaller pieces. Then, the material is subjected to enzymatic disaggregation to break down the extracellular matrix (breaking down the cell envelope by means of molecules (enzymes) that act on specific places.
- A culture medium and a matrix are added. The former contains specific nutrients to keep the cells alive: serum, glutamate, glutamine, salts, vitamins, water, and biomolecules. The latter provides some structure.
- Cell replication and differentiation.
- Obtaining the product: animal tissue without a well-defined structure.
As far as taste is concerned, consumer surveys indicate that the vast majority of consumers find that artificial meat does taste similar to real meat. What needs to be improved is its appearance and texture for the reasons mentioned above.
Besides, the production of artificial meat on an industrial scale, i.e. using bioreactors, is very complicated at the moment. However, the artificial meat pioneer Mark Post -who created the first in vitro hamburger in 2013- speaks of possible improvements to laboratory meat by increasing the production of omega 3 and 6 cells to make them healthier and more nutritious.
The first country to approve the consumption of this type of food was Singapore, specifically in December 2020. In Spain, at the beginning of 2021, the Ministry of Science, through the Spanish Centre for the Development of Industrial Technology (CDTI), granted 3.7 million euros to eight companies to develop laboratory meat, healthy fats and functional ingredients.
The world leaders in this field are the USA and Israel, but Spain could soon be in the vanguard thanks to these investments.
For now, we have to wait and see how this issue will continue to unfold, but it looks like we will have news soon.
POSITIVE AND NEGATIVE ASPECTS
- Reduction of energy use, greenhouse gas emissions, water consumption and land use.
- Environmental impact of cell culture infrastructures.
- The tissue obtained has no immune system, so the contamination risk is high. Reducing this risk calls for strict sanitary controls.
- Many single-use-plastic items are used.
- The likelihood of cell deregulation due to cell multiplication conditions, and its possible negative effects on human health, must be assessed.