The urgency for alternative protein sources is pressing. According to the United Nations, about one in 11 people worldwide experienced hunger in 2023, and more than three billion people could not afford a healthy diet. These challenges point to the need for food systems that deliver more nutrition while using fewer resources.
What is the solution? For many scientists, the answer lies with fungi. Rich in essential amino acids, lipids, vitamins, minerals, antioxidants, and dietary fibres, fungal biomass serves as a valuable alternative protein source.
Yet how to grow sufficient quantities of edible fungi? The answer is with waste food. Fungi can grow on food industry leftovers, such as apple pomace and whey from apple juice and cheese manufacturing. Are there other sources?
Turning to carrots
Scientists have discovered a means to turn carrot processing leftovers into a nutritious protein. By growing edible fungi on carrot side streams, researchers managed to produce fungal mycelium that can replace traditional plant-based proteins in foods like vegan patties and sausages.
To identify the most promising option, the researchers tested 106 different fungal strains grown on side streams from orange and black carrots used in natural colour production. Each fungal strain was evaluated for growth performance and protein output. One fungus emerged as the top candidate: Pleurotus djamor (pink oyster mushroom).
Pink oyster mushrooms are widely cultivated. The mushrooms are suited for many cooked applications, such as sautéing, boiling, roasting, or frying. The mushrooms can be sautéed or stir-fried with other vegetables, added to pasta dishes, sprinkled on top of pizza, added to grain bowls, sautéed with eggs, boiled in soups, chowders, or stews, or cooked into risotto.
After selecting this species, the researchers adjusted growth conditions to increase protein yield. The resulting protein showed biological values similar to those of animal and plant proteins, meaning it could be efficiently used by the human body. The P. djamor mycelia were also low in fat and contained fibre levels comparable to other edible fungi.
How does it taste?
When people sampled the foods, many preferred the versions made entirely with the fungal protein over those made with soy or chickpeas.
Volunteers evaluated patties contained 0%, 25%, 50%, 75% and 100% fungal protein. The participants were asked to assess the patties based on texture, flavour, and aroma. A key finding was that participants preferred the patties made entirely with mycelium over those made entirely with soy.
“This study is a significant step towards a circular economy by transforming valuable food side streams into a high-quality protein source, highlighting the potential of fungal mycelium in addressing global food security and sustainability challenges,” explains Martin Gand, the lead research scientist with the study.
The findings suggest that fungal mycelia could serve as a sustainable and appealing protein source.
The study appears in the Journal of Agricultural and Food Chemistry, with the research paper titled “Pleurotus djamor Mycelium: Sustainable Production of a Promising Protein Source from Carrot Side Streams.”
