When we talk about proteins, the animals they come from immediately come to mind. Even if, the variety of those coming from plant sources should not be underestimated.
In fact, even if the consumption of meat/year is not decreasing, at the same time the demand for vegetable alternatives compared to animal proteins is continually growing. An appreciation due both to the increase in those who follow a vegetarian or vegan diet, and to the desire to eat less meat for ethical, environmental or health reasons (especially red and processed meat, declared carcinogenic in 2016 by the World Health Organization), and to the simple curiosity of trying new flavors.
Among the simplest alternatives we find legumes - beans, chickpeas, peas and lentils - which can be eaten "naturally" or processed, such as in the form of burgers or pastes (e.g. hummus).
Staying among legumes, soybeans are widely used, especially for processed foods. In fact, products such as tofu or tempeh can be made from this legume. Tofu is obtained by curdling soy milk and subsequent pressing and for this reason it is considered a "vegetable cheese". Tempeh, on the other hand, derives from the fermentation of yellow soybeans. The result of fermentation is a kind of loaf that can be used in different ways in the kitchen.
Staying on the fermentation process, it is possible to obtain mopur, that is a vegetable food with an appearance similar to “bresaola” and it is obtained from the fermentation of wheat.
By using wheat gluten, it is possible to obtain seitan and “muscolo di grano”. The latter is much richer in protein than seitan, since legume flours are also added to the wheat proteins during preparation.
In addition to legumes and cereals, algae and vegetables such as spirulina, hemp or jackfruit can be used to obtain protein-rich foods. Spirulina is an algae with a high protein content (about 65%) and is rich in iron. Hemp is also particularly rich in protein, in addition it contains essential fatty acids such as omega 3 and 6. Jackfruit is not particularly known, especially in western countries, but in addition to being a good source of protein, it is rich in vitamin C, potassium, calcium, magnesium and phosphorus, also does not contain gluten.
Another valid alternative is Quorn, that is a product based on mycoproteins (obtained from the fermentation of a fungus, Fusarium Venenatum), rich in protein and low in fat. This product has a texture similar to meat and is commercially available in various formats (e.g. meatballs, mince, sausages, burgers, fillets, cold cuts and many others).
In addition to products with a texture similar to meat, those products that try to imitate their flavor are also increasingly popular (the so-called "fake meat"). In particular, they try to imitate the typical ferrous flavor of the meat, inserting in these products the heme (in this case extracted from vegetables such as soy) and the red color, exploiting natural colors such as those of the beet. The result is a product rich in protein with a texture and flavor similar to meat: this can be interesting, as well as for those who follow a vegetarian/vegan diet, also for those who are tied to the taste of meat, but want to reduce its consumption.
Finally, in a slightly futuristic perspective, studies are underway on the possibility of producing meat in the laboratory (clean meat), exploiting the stem cells of animals. A real meat cultivation that allows the generation of tissues from stem cells and does not require intensive breeding, slaughtering and the use of hormones and antibiotics, eliminating the environmental impact of the farms. For now, it has been possible to obtain this "clean meat" only on a laboratory scale, with a very high production cost, but it is not impossible that in a few years we will find "laboratory meat" on the shelves of our supermarkets.