Currently, there are many options for replacing animal proteins in human nutrition, although some products are not yet ready for introduction into the food market.
Therefore, further development of production processes is essential, e.g. improving sensory quality and meatiness among meat-eating consumers are the most important parameters for increasing the acceptance of meat substitutes.
In the second part of our article, we continue to explore possible alternative protein sources.
3.3. Mushrooms
Mushrooms are consumed directly due to their high nutritional value and good taste. However, out of the approximately 2000 edible mushroom species, only about 25 have the status of edible in the public consciousness, and the range of commercially grown species is still far behind this.
The most commonly grown mushrooms worldwide are the champignon (Agaricus bisporus), shiitake (Lentinus edodes), straw mushroom (Volvariella volvacea) and oyster mushroom (Pleurotus ssp.), all of which belong to the so-called basidiomycetes (pillar fungi). The mushroom and its high-quality protein can be used not only in the form of the mushroom body, but also as mycelium in meat substitute products.
Since mushrooms can live on a wide variety of media, they also have great potential for recycling by-products or waste.
Mushroom cultivation is also possible in surface and underwater cultures – However, which cultivation method is more suitable depends very much on the mushroom in question, but from a technological and economic point of view, those varieties that can be grown using liquid culture methods have an advantage.
3.4. Plants
Plant-based meat substitutes are already well established on the market and are very popular. Most of the products are based on soy, e.g. tofu obtained by fermentation, textured soy protein (“soy meat”) or tempeh obtained by fermenting soybeans.
In addition to soy products, there are other meat substitutes on the market, e.g. the best known is seitan made from wheat protein.
Proteins from legumes, such as peas or lupins, are also used to produce meat substitutes and as technological additives in a wide range of foods, such as baked goods, dairy products or ice cream.
With the appropriate selection of varieties (e.g. sweet lupin (L. angustifolia), which has a low alkaloid content and therefore a less bitter taste) and technological developments in the production of lupin protein isolate, the prerequisites for the widespread use of this material in the production of meat substitutes have been created.
The great advantage of lupine is that it is guaranteed to be GMO-free, can be produced in domestic cultivation and can be marketed with these claims. However, important parameters such as organoleptic quality, shelf life and the preservation of the desired technological and physiological properties are still subject to further development.
In addition, protein-containing by-products of vegetable oil production – e.g. the press residues of oilseeds (sunflower, oilseed rape) – are also suitable as a source of protein for human nutrition.
Due to the large production volume, protein isolates from rapeseed and sunflower have already been investigated in numerous research projects.
But the press residues of many other plants whose oils are used for commercial purposes (e.g. flax, cotton, peanuts, pumpkin, sesame or hemp) also contain high-quality proteins that can be used in other areas. The focus is not only on the extraction of protein concentrates and isolates, but also on the innovative production of high-quality, preferably unprocessed proteins.
The functional and nutritional properties of proteins or protein isolates from many feed crops have already been investigated in numerous studies. Data can be found, for example, for flax, almonds, sesame, hemp, fenugreek, gluten-free pseudocereals such as amaranth, quinoa and buckwheat or sorghum. In addition to the predominantly good nutritional properties, extracts obtained from plants are often attributed with useful technical and functional properties.
The use of duckweed (Lemnoideae sp.), which is regularly consumed in Thailand, is an important staple food there, especially in the traditional vegan diet, and could therefore also be the basis for the production of meat substitutes in Europe in the future.
Another alternative approach is the extraction of membrane proteins from leaves, which has so far been investigated using the example of sugar beet. However, comprehensive work is still lacking at this point regarding the technology and functional properties of the above proteins.
There are also recent developments in the field of vegetable-based meat substitute production. The main ingredients are peas, carrots and onions, which are processed into meat imitations with or without protein isolates. However, comprehensive work is still lacking here that would investigate the technology and functional properties of the above proteins with regard to their use as meat substitutes.