Mycoprotein Can Be Digested Just As Well As Meat, But It Needs to Be Maximised: Study

Mycoprotein can deliver significant nutritional benefits with high protein digestibility and mineral accessibility; however, its true potential depends on the fungal strain and how it’s cultivated.

Protein from fungi is as complete and digestible as that from chicken, beef and fish, according to a new study shedding light on the potential of mycelium.

Mycoprotein, derived from filamentous fungi, has been around for decades and has sustained a reputation as a healthy, sustainable protein source.

As attention turns to protein quality and micronutrient access, alternative proteins have come under scrutiny. This is mainly because most plant proteins, on their own, don’t contain all essential amino acids, and aren’t as easily digestible as animal-derived sources.

Mycoprotein isn’t a plant-based ingredient, though. And a new study by the University of Borås in Sweden highlights how fungi can match or even beat animal proteins when it comes to protein and mineral accessibility.

“Filamentous fungi have great potential as a sustainable protein source,” said study author Ricky Wang. However, he noted that mycoprotein’s nutritional digestibility “significantly depends” on how the microbes are cultivated, underscoring their potential to be optimised further to maximise protein and mineral accessibility.

“With the right cultivation techniques, they could become a key to more resilient and climate-smart food production systems,” he said.

Amino acid and protein digestibility levels of mycoprotein

Wang grew five species of filamentous fungi via submerged fermentation in bioreactors, and then analysed their nutritional values using a standardised method called Infogest 2.0, which simulated digestion in the mouth, stomach and intestines under lab conditions.

The mycoproteins were found to have 41-48% of essential amino acid values, comparable to animal proteins like chicken breast, beef or salmon (around 44%).

Notably, the filamentous fungi were especially rich in lysine, whose levels ranged from 8-14% of total amino acids. “This is significant because lysine is considered the first limiting amino acid in most cereal grains, which typically contain less than 5% lysine per unit of protein, whereas legumes such as beans average at about 7%,” the paper reads, outlining mycoprotein’s advantages over plant proteins.

It also noted that mycoprotein is as efficiently digested as chicken and fish, with Aspergillus oryzae and Rhizopus oligosporus showing the highest amino acid accessibility at about 92%. Neurospora intermedia, Fusarium venenatum, and Rhizopus delemar had protein digestibility levels between 81% and 84%.

There is a caveat. The protein digestibility was comparable to animal-derived sources only in fungi cultivated in semi-synthetic media containing glucose and yeast extract, as cultivation conditions – particularly the presence of polyphenols – could strongly influence this factor.

The study further revealed that prolonged cultivation of fungal biomass leads to a substantial reduction in protein content and an increase in cell wall material, though only slightly decreases its amino acid accessibility.

Mycoprotein boosts iron absorption, though optimising conditions is key

In terms of micronutrients, Wang found that the iron present in mycoprotein can be absorbed more easily, thanks to the absence of phytate, an antinutrient that can significantly reduce the bioavailability of such essential minerals.

Mineral accessibility was higher in biomass that was cultivated on glucose media, compared to oat-based media, which showed minor antinutient effects despite low phytate levels. Similarly, fungi cultivated in winery sidestreams accumulated polyphenols from grape marc, significantly lowering mineral accessibility.

“For fungi that are cultivated on a winery side stream, their nutritional value could be lower compared to if the medium consisted of only sugar. Optimising these conditions could unlock their full potential, paving the way for more resilient and sustainable food systems,” said Wang.

His research showed that mineral concentration in the cultivation media strongly influences both the mineral content and bioaccessibility in some mycoprotein strains. Low iron concentrations can produce fungal biomass that enhances iron accessibility, while fungi grown in high-zinc media show high zinc accessibility.

The benefits of mycoprotein have been touted for years, and by many studies. In 2023, one paper highlighted its nutritional and environmental prowess, ability to scale in a cost-competitive manner, and potential to tackle global hunger and food insecurity.

It’s why the ingredient is also being used to target the longevity space. Dutch mycoprotein producer The Protein Brewery’s mycoprotein innovation, Fermotein, contains spermidine, a polyamine that has gained popularity in anti-ageing formulations.

“We conducted detailed compositional analyses, including screening for polyamines such as spermidine,” its CEO Thijs Bosch told Green Queen last month. “Altogether, Fermotein contributes to healthy ageing by supporting protein adequacy, fibre intake, and overall dietary nutrient density, rather than by targeting a single longevity pathway.”