11.4 Cells and mycelium as human food

The two most successful applications for fungal biomass in the food industry, which are yeast extract and Quorn™ mycoprotein™, illustrate very different ways of using fungal vegetative growth as food. The first example is the conversion of brewery wastes, using low-technology processes into flavourings, diet supplements and products like Marmite, Meridian Yeast Extract and Vegemite. These yeast extracts illustrate one successful commercial model: start with a cheap (ideally, waste) feedstock and use conventional production processes to make a product that sells at a relatively high retail price. The alternative model with a fungal product currently on the market is the mycoprotein™ Quorn™. This is the mycelium of a specific strain of the filamentous soil-fungus Fusarium venenatum, grown on food-grade glucose as the carbon source, usually derived from wheat or maize starch, in a 45-m tall airlift fermenter in continuous culture mode (i.e. medium is added continuously and mycelium + spent medium is harvested at a rate equal to the production of new hyphae; for details see Section 17.18). It is consequently a high-technology product (Trinci, 1991, 1992; Wiebe, 2004). Mycoprotein is high in protein and fibre, and low in fat, cholesterol, sodium, and sugar. Compared with other protein food sources mycoprotein does well for vitamin B9 (folate), vitamin B12, calcium, phosphorous, magnesium and zinc; its content of choline (an essential nutrient required for synthesis of phospholipids of cellular membranes)compares well with other foods that have some of the highest choline profiles. Mycoprotein may help maintain healthy blood cholesterol levels, promote muscle synthesis, control glucose and insulin levels, and increase satiety. The market virtues of the material centre on its filamentous hyphal structure which enables it to simulate the fibrous nature of meat (Finnigan et al., 2019; Derbyshire & Delange, 2021) (Fig. 12).

Quorn™ myco-protein prepared as a low-fat and cholesterol-free healthy alternative to conventional sliced meat products
Fig. 12. Supermarket packages of Quorn™ mycoprotein™ products. Top shows a chiller pack of Quorn™ Pieces, which are described as ‘perfect for a cracking curry or a sizzling stir fry’; they contain 95% Mycoprotein™ (rehydrated free range egg white, natural flavouring, and the firming agents, calcium chloride and calcium acetate are the only other ingredients) and are entirely meat free yet high in protein and low in saturated fat.
Bottom shows two chiller packs of Quorn™ mycoprotein™ prepared as a healthy meat free alternative to conventional sliced meat products. Mycoprotein™ might be the way we can satisfy our taste for meat without costing the Earth. View https://www.quorn.co.uk/ for other product choices and recipes.

Coupled with the inherent nutritional value of fungal biomass, this permits the product to be sold as a low-fat, low-calorie, cholesterol-free vegetarian health food to consumers who can afford to choose Quorn™ as an alternative to meat. At point of sale, Quorn™ can be more expensive than many meat products (and most mushrooms), but it is sold as a healthy ‘meat alternative’. Evidently, it is positioned in the market to be sold to those who can choose to pay a premium price for an environmentally-friendly vegetarian health food (visit https://www.quorn.com/).

Updated May, 2021