At the laboratory stage, they are produced from photosynthetic microorganisms (cyanobacteria, microalgae, etc.)

At the industrial roll-out stage or, in some cases, already marketed, they are produced without using resources that compete with human and animal food production

At the industrial stage, they are produced from plants rich in sugar (such as beet), starch (such as corn or wheat) or oil (such as rapeseed or soybean)