VTT Study Finds Mycoprotein a Sustainable Superfood & Next-Level Nutrient Powerhouse – vegconomist

Research by a team of scientists at VTT Technical Research Centre of Finland shows that mycoprotein is a valuable ingredient: it offers digestible proteins and, unlike meat, dietary fiber. 

These findings are relevant because various studies suggest that dietary fiber intake significantly reduces the risk of cardiovascular disease, cancer, stroke, type 2 diabetes, high cholesterol, and hypertension.

The VTT study evaluated the nutritional quality of different microbial biomass samples by assessing their protein digestibility and carbohydrate (fiber) fermentability in the colon using in vitro methods. According to the researchers, previous studies centered on protein content, overlooking fiber, glucose, and other macronutrients.

Four microbial biomasses were selected to determine whether they could be both a protein and dietary fiber source for the human diet: one hydrogen-oxidizing bacterial strain (HOB) called Nocardioides nitrophenolicus (KGS-27) used by the companies Air Protein and Solar Foods; two strains of filamentous fungi, Rhizopus oligosporus and Paecilomyces variotii (Enifer‘s PEKILO); and one yeast strain, Rhodotorula babjevae. The commercial mycoprotein Quorn was used as a reference. 

Digestible proteins

The researchers found that all microbial biomass samples have a sufficient amino acid profile, meeting the required amounts of essential amino acids according to WHO recommendations, including lysine, which is often limited in plant-based sources.

Mycoproteins had the highest protein content among these microbial biomasses. Still, their protein content varied significantly, ranging from 20.2% in Rhizopus to 46.1% in the PEKILO sample. Quorn offers 39 %.

Regarding protein digestibility, yeast had the highest (85%) and bacterial biomass the lowest. Mycoproteins were found to have high digestibility rates and better protein digestion than plant sources. 

Among the mycoproteins tested, PEKILO stood out with a digestibility range of 56% to 77%, outperforming Quorn at 45%. The study says that this superior digestibility can be attributed to differences in the cell wall composition of each biomass and the absence of anti-nutritional compounds typically found in plant proteins.

However, the research reveals that heat treatments, often applied in food production to improve safety and processability, impact the protein digestibility of microbial biomass. The authors highlight that harsh treatments decrease digestibility by binding proteins with cell wall structures. 

Dietary fibers for gut health

The study shows that fungal biomass samples had a higher total dietary fiber content (31-43%) than bacterial biomass (25.7%). Most dietary fiber in the fungal biomass is insoluble (harder to break down but beneficial for intestinal function). In contrast, the dietary fiber in the bacterial biomass is mainly soluble or easier to break down (23.5%), and 2.2% is insoluble.

But more significantly, the study revealed that the dietary fiber content of the microbial biomass samples does not affect protein digestibility. The researchers note that the dietary fiber in the samples did not directly correlate with protein digestion. They suggest that the structure of the microbial biomass samples, such as cell wall composition and porosity, can affect protein digestibility, with some samples being more accessible to digestive enzymes. 

Moreover, the study found that yeast and fungal samples had fermentability similar to wheat bran and promoted the production of short-chain fatty acids, suggesting their dietary fiber components may offer potential health benefits.  

Beneficial gut bacteria

In addition, the authors explain that consuming mycoprotein has been shown to increase the presence of beneficial gut bacteria such as Lactobacilli, Roseburia, and Akkermansia in healthy adult humans, as opposed to a diet high in red meat, which has been linked to risk factors for cancer.

Further studies are needed to understand the reasons for differences in protein digestibility and dietary fiber fermentability, including cell wall structures and post-processing techniques, the authors note.

“Protein digestibility of the microbial biomass samples did not correlate with DF content (neither insoluble nor soluble forms). In plant-based materials, the presence of DF has been reported to reduce the protein digestibility by inhibiting the access of digestive enzymes to the protein,” the researchers highlight.