Proteins and mushrooms: the potential of mycoproteins

In the global landscape of sustainable protein sources, mushroom proteins are emerging as key players in a food revolution. While traditionally valued for their gastronomic and nutritional worth, mushrooms are revealing unexpected potential as an alternative source of high biological value protein. This article stems from the need to deeply explore the relationship between mushrooms and proteins, with particular focus on mycoproteins - a resource that could redefine our approach to sustainable nutrition.

Drawing inspiration from the BioInnovation Institute's innovative project and recent scientific research, we'll analyze the nutritional value of mycoproteins, production processes, environmental impact, and future potential of this fascinating mycological resource. We'll discover how mushrooms, organisms that have always existed at the boundary between plant and animal kingdoms, can offer concrete solutions to 21st century food challenges.

What are mycoproteins?

Mycoproteins represent an innovative category of proteins derived from fungal biomass, obtained through controlled large-scale fermentation processes. 

Definition and origin

Unlike traditional animal protein sources, these proteins are produced by cultivating specific strains of filamentous fungi in highly controlled environments, similar to those used for antibiotic or industrial enzyme production.

The discovery of mycoproteins dates back to the 1960s, when British researchers sought alternative protein sources to meet growing global food demand. The fungus Fusarium venenatum was identified as particularly promising, thanks to its high protein content (about 45% of dry weight) and its ability to grow rapidly on simple substrates. Today, after decades of refinement, mycoproteins have reached a level of quality and safety that makes them competitive with traditional animal proteins.

The protagonists: filamentous fungi

The fungal species used for mycoprotein production mainly belong to the Ascomycota division, particularly the Fusarium genus. Fusarium venenatum, the most commercially used strain, was selected for its genetic stability, high protein content and lack of toxicity. This filamentous fungus grows forming a dense network of hyphae that, once harvested and processed, create a product with a texture surprisingly similar to meat.

Other promising fungi for mycoprotein production include species from the Aspergillus genus and some basidiomycetes like Pleurotus ostreatus (oyster mushroom), although these present greater challenges in industrial-scale cultivation. Research is exploring new species and strains optimized through traditional breeding techniques and, more recently, genetic editing, aiming to further improve nutritional profile and organoleptic characteristics.

Production process

The industrial production of mycoproteins is a fascinating example of biotechnology applied to nutrition. The process begins with preparing a culture medium containing a carbon source (typically glucose derived from wheat or corn starch), a nitrogen source (often ammonia or urea), mineral salts and vitamins. This medium is sterilized and inoculated with the selected fungal strain.

Fermentation occurs in large bioreactors (up to 150,000 liters) under strictly controlled conditions: temperature between 28-30°C, pH 6.0 and with constant oxygen supply. Under these optimal conditions, the fungus grows rapidly, doubling its biomass every 4-5 hours. After about 48 hours, the biomass is harvested by centrifugation, heated to 65°C to reduce RNA content (which could be harmful in large quantities) and then processed to obtain the final product.

A revolutionary aspect of this process is its efficiency: from 1 kg of substrate up to 5 kg of mycoprotein can be obtained, an impressive ratio compared to beef production, where about 25 kg of feed are needed to produce 1 kg of meat. This makes mycoproteins not only a sustainable protein source but also potentially more economical on large scale.

Nutritional value of mycoproteins

Mycoproteins offer a complete and well-balanced amino acid profile, containing all nine essential amino acids that our body cannot synthesize on its own.

Protein composition

 According to studies published in the Journal of Nutrition, the PDCAAS (Protein Digestibility Corrected Amino Acid Score) of mycoproteins is 0.91, very close to that of "complete" animal proteins like egg (1.0) or beef (0.92).

Particularly interesting is the high content of branched-chain amino acids (BCAAs) - leucine, isoleucine and valine - which represent about 20% of the total. These amino acids are fundamental for muscle protein synthesis and post-exercise recovery, making mycoproteins especially interesting for athletes and sportspeople. Moreover, mycoproteins are rich in glutamine (about 15% of total), an amino acid important for gut health and immune function.

A unique aspect of fungal proteins is the presence of chitin and chitosan in the cell wall, polysaccharides that can positively influence satiety and lipid metabolism, as demonstrated by research published in the European Journal of Clinical Nutrition. These substances, absent in animal proteins, may confer additional metabolic benefits beyond simple protein supply.

Other nutrients

Beyond proteins, fungal mycoproteins are an exceptional source of other beneficial nutrients. Fiber is particularly abundant, representing about 25% of dry weight, with a predominance of beta-glucans - polysaccharides with demonstrated cholesterol-lowering and immunomodulatory effects. A 2017 study published in Clinical Nutrition showed that regular consumption of mycoproteins can reduce LDL cholesterol by 10-12% in hypercholesterolemic subjects.

Regarding micronutrients, mycoproteins contain significant amounts of B vitamins, particularly riboflavin (B2), niacin (B3) and biotin (B7), plus minerals like zinc, selenium and potassium. The bioavailability of these micronutrients is generally good, though lower than animal sources, as reported by a 2020 meta-analysis published in Advances in Nutrition.

Comparison with other protein sources

A comparative analysis between mycoproteins and other protein sources reveals interesting advantages and peculiarities. Compared to beef, mycoproteins offer similar protein content (11-15g per 100g of product) but with only 1-2g of total fats (versus 15-20g in meat) and zero cholesterol. They also contain 6-8g of fiber, completely absent in animal proteins.

Compared to traditional plant proteins like soy, mycoproteins show a more complete amino acid profile (especially regarding lysine and methionine) and a more meat-like texture, making them more versatile in cooking. A 2021 study in Food Chemistry highlighted that the digestibility of fungal proteins (about 85%) is intermediate between animal proteins (90-95%) and plant proteins (70-80%).

A particularly interesting aspect is the absence of common allergens like those present in soy or wheat, making mycoproteins a valid option for those with these intolerances. However, it's important to note that a small percentage of people may develop sensitivity to fungal proteins themselves, though these cases are rare.

Sustainability and environmental impact

The environmental impact of switching to plant-based protein sources is significant - let's see why.

Production efficiency

The production efficiency of mycoproteins represents one of its most significant advantages over traditional protein sources. According to FAO data, producing 1 kg of mycelium protein requires only 0.1-0.3 kg of protein input from substrate, versus 6-10 kg needed for beef. This translates to a protein conversion efficiency 90% higher than animals.

Land use is another crucial parameter: mycoproteins require about 1/20 of the land needed to produce the same amount of protein from beef. A medium-sized production plant (10,000 tons/year) can meet the protein needs of tens of thousands of people using an area comparable to a large supermarket. This aspect is particularly relevant in an era of increasing pressure on land resources.

Water consumption is another strong point: while producing 1 kg of beef requires about 15,000 liters of water (including that for growing feed), mycoproteins need only 300-500 liters per kg, as demonstrated by an LCA (Life Cycle Assessment) study published in Environmental Science & Technology in 2022. This reduced water requirement makes the technology particularly suited to water-scarce regions.

Greenhouse gas emissions

The carbon footprint of mycoproteins is significantly lower than traditional animal proteins. While beef production generates 25-30 kg of CO2 equivalent per kg of protein, mycoproteins register only 1-2 kg CO2 eq/kg, according to Carbon Trust data. This places them at the same level as the best plant proteins in terms of climate impact.

An often overlooked aspect is the ability of fungal fermentation processes to use agricultural and industrial byproducts as substrate. Recent research is exploring the use of food industry waste (whey, fruit peels, straw) as raw material, transforming potential waste into resources. This circular approach could further improve mycoproteins' overall sustainability.

It's important to note that mycoprotein sustainability depends heavily on the source of the carbon substrate. Using glucose derived from dedicated crops (like corn or wheat) reduces some environmental benefits, while using second-generation raw materials (like lignocellulosic waste) could make the process even more sustainable. This is one of the most active research fronts in the field, as demonstrated by the BioInnovation Institute's MICOPROTEIN project.

Applications and innovations

Mushroom applications in food are countless - some are more than innovative, valid alternatives to traditional nutrition that don't compromise on taste in dishes served at the table. 

Meat alternatives

As highlighted by the BioInnovation Institute project, mycoproteins are revolutionizing the plant-based meat alternatives sector. Their intrinsic fibrous structure, resulting from fungal hyphae growth, makes them particularly suitable for mimicking animal meat texture without needing complex texturization processes.

Current mycoprotein-based products range from burgers and meatballs to chicken-like strips and fish substitutes. The versatility of these proteins allows replicating different meat types, from more processed products (like sausages and nuggets) to simpler preparations (like stews and fillets). A Good Food Institute study showed that mycoprotein-based products score significantly higher in acceptance tests compared to other plant alternatives, especially regarding texture and juiciness.

Texturization technologies

Mycoprotein processing technologies have made giant leaps in recent years. High-moisture extrusion (HME) is currently the most advanced method, allowing creation of aligned protein fibers that perfectly mimic muscle meat's fibrousness. This process, combining heat, pressure and mechanical shear, transforms fungal biomass into a product with rheological properties similar to meat.

Other promising techniques include 3D printing of mycoproteins, enabling creation of complex, customized structures, and use of enzymes (transglutaminase) to improve cohesion and consistency. Research published in Innovative Food Science & Emerging Technologies showed that applying electric fields during processing can further improve protein fiber alignment, getting even closer to natural meat texture.

Beyond food

Mycoprotein applications extend well beyond the food sector. In pharmaceuticals, mycoproteins are being studied as drug carriers, leveraging their biocompatibility and ability to modulate active ingredient release. The presence of chitin and chitosan in fungal cell walls makes them particularly suitable for controlled-release applications.

In materials, mycoproteins are showing potential as sustainable plastic alternatives. Researchers at Rensselaer Polytechnic Institute have developed mycelium-based thermoformable materials with properties similar to polystyrene but completely biodegradable. Other applications include yarns for fabrics, food packaging and even lightweight, insulating construction materials.

A particularly innovative field is using mycoproteins in production of biosensors and biodegradable electronic components. Fungal hyphae's ability to conduct electricity and their network structure make them interesting candidates for "green" electronics. These applications, though still experimental, demonstrate the versatility and transformative potential of this fungal resource.

Home cultivation of protein-rich mushrooms

Through mushrooms, it's possible to incorporate proteins into your diet... by growing them yourself!

Protein-rich species

For mycology enthusiasts and self-consumption, several home-cultivable mushroom species have particularly high protein content. Among these stands out Pleurotus ostreatus (oyster mushroom), which besides being one of the easiest mushrooms to cultivate, contains 25-30% protein by dry weight, with a well-balanced amino acid profile. University of Naples research showed protein content can vary significantly depending on substrate used, with maximums reached on substrates enriched with wheat bran.

Shiitake (Lentinula edodes), though slightly less protein-rich (15-20%), contains all essential amino acids and is particularly rich in glutamic and aspartic acid, contributing to characteristic umami flavor. The common button mushroom (Agaricus bisporus), often underestimated, can reach 20-25% protein when cultivated on optimized substrates, as shown by French INRA studies.

Special mention goes to Coprinus comatus (shaggy mane), which can contain up to 35% protein by dry weight and has unusually high L-DOPA content, a dopamine precursor that may have neuroprotective effects. Unfortunately, its cultivation is more complex due to the fruiting body's rapid autodigestion.

Optimized cultivation techniques

To maximize protein content in home-cultivated mushrooms, it's essential to pay attention to several factors:

1. Substrate choice: adding nitrogen sources like wheat bran (10-20%), soy flour (5-10%) or cottonseed meal can significantly increase protein content. A Pakistani study showed adding 15% rice bran increases Pleurotus protein content by 22% compared to straw-based substrates.
2. Growth conditions: optimal temperature varies by species, but generally slightly lower temperatures (18-22°C) during fruiting favor slower metabolism and greater protein accumulation. Relative humidity should be maintained at 85-90% to avoid water stress that could compromise protein synthesis.
3. Harvest timing: mushrooms harvested at "button" stage (before full cap opening) tend to have higher protein concentration. University of Florida research showed Pleurotus protein content can decrease up to 15% if left to grow beyond optimal maturity.
4. Post-harvest treatment: low-temperature drying (40-50°C) better preserves protein content than high-temperature drying or fresh storage. Using solar dryers with dehumidification is particularly effective, as shown by studies in tropical climates.

Future perspectives

Mycoproteins represent one of the most promising solutions to reconcile food security and environmental sustainability. With a growing global population and increasingly limited resources, fungi's ability to efficiently convert simple substrates into high-quality proteins could play a crucial role in transitioning to more resilient food systems.

Advances in fungal biotechnologies, from selecting more performant strains to optimizing fermentation processes, are rapidly overcoming these alternative proteins' initial limitations. Research is exploring innovative frontiers like using unconventional wild mushrooms, optimizing amino acid profile through synthetic biology approaches, and developing co-cultures with beneficial bacteria to further improve nutritional value.

For mycology enthusiasts, this represents a fascinating exploration field combining passion for mushrooms with global sustainability challenges. From wild harvesting to home cultivation, to understanding the most advanced biotechnological applications, the mycoprotein world offers learning and engagement opportunities at all levels.

As the BioInnovation Institute's MICOPROTEIN project and other similar initiatives continue pushing this technology's boundaries, we can expect mycoproteins to assume an increasingly central role in our diets and, more generally, in the future circular economy.