Microbial biomass is produced commercially as single-cell protein (SCP) for human food or animal feed and as viable yeast cells for the baking industry. The industrial production of bakers' yeast started in the early 1900s and yeast biomass was used as human food in Germany during World War I. The development of large-scale processes for the production of microbial biomass as a source of commercial protein began in earnest in the late 1960s. Several of the processes investigated did not come to fruition owing to political and economic problems but the establishment of the ICI Pruteen process for the production of bacterial SCP for animal feed was a milestone in the development of the fermentation industry. This process used continuous culture on a large scale (1500 m3). The economics of the production of SCP as animal feed were marginal, which eventually led to the discontinuation of the Pruteen process. The technical expertise gained from the Pruteen process assisted ICI in collaborating with Rank Hovis McDougall on a process for the production of fungal biomass for human food. A continuous fermentation process for the production of Fusarium venenatum biomass (marketed as Quorn) was developed using a 40-m3 air-lift fermenter.
During the 1960s, it was predicted that by the 1980s there would be a shortage of protein-rich foods. In response to this, research programmes were undertaken to use single-cell biomass as an animal feed. Contrary to the trend, J. Arthur Rank instructed the Rank Hovis McDougall (RHM) Research Centre to investigate converting starch (the waste product of cereal manufacturing undertaken by RHM) into a protein-rich food for human consumption.
The filamentous fungus, Fusarium venenatum, was discovered in a soil sample in 1967. In 1985, RHM was given permission to sell mycoprotein for human consumption after a ten-year evaluation programme.
Quorn as a retail product (it derives its name from the Leicestershire village of Quorn), was first produced in 1985 by Marlow Foods (named after Rank Hovis McDougall's headquarters in Marlow, Buckinghamshire), a joint venture between RHM and Imperial Chemical Industries (ICI), who provided a fermenter left vacant from their abandoned single-cell feed programme. The two partners invested in patents for growing and processing the fungus, and other intellectual properties in the brand.
Quorn entered distribution in the UK in 1993, introduced to other parts of Europe in the 1990s, and to North America in 2002. The initial advertising campaign for Quorn featured sports personalities, including footballer Ryan Giggs, rugby player Will Carling, and Olympic runner Sally Gunnell. In 2013 the company appointed Mo Farah as its ambassador in a marketing push for fitness.
Quorn brand mycoprotein is sold in ready-to-cook forms, such as cubes and a form resembling minced meat. The company later introduced a range of chilled vegetarian meals, including pizzas, lasagne, cottage pie, and products resembling sliced meat, hot dogs, and burgers. By 2005 Quorn enjoyed around 60% of the meat-replacement food market in the UK, with annual sales of around £95 million. By 2006 it was available in stores in: the UK; Europe (Belgium, Denmark, Ireland, Netherlands, Sweden and Switzerland); and North America (Canada and United States). Since June 2010, it has been available in Australia. In May 2012 Quorn Foods opened the German website quorn.de to relaunch Quorn in Germany.
After its producer switched to using free-range eggs as an ingredient, the Vegetarian Society gave the product its seal of approval.
In 2004, McDonald's introduced a Quorn-branded burger bearing the seal of approval of the Vegetarian Society. As of 2009, the Quorn burgers were no longer available at any McDonald's restaurant in the UK. In 2011 Quorn Foods launched a vegan burger into the US market, using potato protein as a binder instead of egg albumen, to confer vegan status. According to Quorn's website, by 2013 a number of Quorn items were available in US markets, most of which are vegetarian but not vegan, as they contain milk or cheese and egg white or albumen. In addition, some contain wheat, gluten and/or soy.
As of 2014, it was reported that most consumers of Quorn are meat eaters rather than vegetarians.
Originally conceived in 1985 and owned by Marlow Foods, a joint venture between Rank Hovis McDougall (RHM) and Imperial Chemical Industries (ICI). RHM exited the business in 1990 by selling its shares to ICI. When ICI spun off its biological products divisions from the core chemical business in 1993, Marlow Foods became a part of the newly formed Zeneca group, later AstraZeneca.
In 2003 AstraZeneca sold Marlow Foods, including the Quorn business and associated trademarks and patents, to Montagu Private Equity for £72m. Montagu sold the business on to Premier Foods in 2005 for £172m.
In 2011 Premier Foods sold Quorn to Exponent Private Equity and Intermediate Capital Group for £205 million. In 2015, the owners put the company up for sale via a business auction process. Attracting bidders including Danone, Kerry Group, McCain Foods and Nomad Foods, it was sold to Monde Nissin Corporation headquartered in the Philippines for £550m ($831m).
Quorn is made from the soil mould Fusarium venenatum strain PTA-2684 (previously misidentified as the parasitic mould Fusarium graminearum). The fungus is grown in continually oxygenated water in large, otherwise sterile fermentation tanks. Glucose and fixed nitrogen are added as a food for the fungus, as are vitamins and minerals to improve the food value of the product. The resulting mycoprotein is then extracted and heat-treated to remove excess levels of RNA. Previous attempts to produce such fermented protein foodstuffs were thwarted by excessive levels of DNA or RNA; without the heat treatment, purines, found in nucleic acids, is metabolised by humans to produce uric acid, which can lead to gout. However two recent studies have found dietary factors once believed to be associated with gout are in fact not, including the intake of purine-rich vegetables and total protein. The Mayo Clinic, meanwhile, advises gout sufferers to avoid some foods that are high in purines.
The product is dried and mixed with egg albumen, which acts as a binder. It is then textured, giving it some of the grained character of meat, and pressed either into a mince resembling ground beef; forms resembling chicken breasts, meatballs, and turkey roasts; or chunks resembling diced chicken breast. In these forms, Quorn has a varying colour and a mild flavour resembling the imitated meat product, and is suitable for use as a replacement for meat in many dishes, such as stews and casseroles.
The final Quorn product is high in protein and dietary fibre and is low in saturated fat. It contains less dietary iron than most meats and the manufacturers have not released much information about additives they use to make Quorn resemble meat. Quorn is considered acceptable in small amounts for babies over 9 months old but should be introduced gradually. The high fibre and low calorie content is better for adults than babies and too much fibre can cause flatulence. The salt content should be checked before giving Quorn to babies since the salt content varies between products.
The carbon footprint of Quorn Frozen Mince in the UK is claimed to be at least 80% less than that of beef.
Quorn for the UK and European market is produced at Marlow's headquarters in Stokesley, North Yorkshire and at nearby Billingham in Stockton-on-Tees.
Quorn's 2002 debut in the US was more problematic than its European introduction. The Center for Science in the Public Interest (CSPI) expressed multiple concerns over the product. Much of the concern from CSPI and others was over the original labeling of Quorn as a "mushroom based" product, since Fusarium venenatum is not a mushroom (rather, it is a microfungus). The sale of Quorn was contested by The American Mushroom Institute, rival Gardenburger, as well as the CSPI. They filed complaints with advertising and trading-standards watchdogs in Europe and the US, claiming the labelling of Quorn as "mushroom based" was deceptive. The CSPI observed that while a mushroom is a fungus, Fusarium is not a mushroom, and stated, "Quorn's fungus is as closely related to mushrooms as humans are to jellyfish."
CSPI also claimed that Quorn could cause allergic reactions and should be removed from stores. Calling the product "fungus food", CSPI claimed in 2003 that it "sickens 4.5% of eaters". The manufacturer (Marlow Foods) disputes the figure, claiming that only 0.0007% (1 in 146,000) suffer adverse reactions and that the strain of fungus it uses does not produce toxins. The CSPI's claims were also described by Leslie Bonci, professor of nutrition at the University of Pittsburgh, as "overblown". Steven Milloy, writing for the American Fox News channel, said "CSPI appears to have an unsavory relationship with Quorn competitor, Gardenburger" and called the CSPI's complaints "unscrupulous shrieking". Gardenburger in turn denied this, saying Milloy's "unsavory relationship" claim was "untrue and groundless". Wendy Preiser, Gardenburger's vice president of marketing, supported the Gardenburger position on the grounds that the company was afraid that Quorn's labels would cause people to be suspicious about all meat-free products.
The UK's Advertising Standards Authority also had concerns over Marlow's practice of marketing Quorn as "mushroom in origin", saying it had been "misleading consumers". The ASA noted "despite the advertiser’s explanation that they used the term because customers were unfamiliar with the main ingredient, mycoprotein, the ASA considered that the claim implied that Quorn was made from mushroom. Marlow Foods were asked either to delete the claim or give in the same font size a statement of the mycoprotein origin of the product or the fungal origin of the product."
Quorn's acceptance in the vegetarian market was hampered by the use of battery eggs in its production process, a practice opposed on ethical grounds by many in the vegetarian community. For this reason, the Vegetarian Society initially did not approve these products. Working with the Vegetarian Society, Marlow began phasing out battery eggs in 2000, and by 2004 all Quorn products sold in the UK were produced without battery eggs, earning the Vegetarian Society's seal of approval.
An asthma attack in 2003 was linked to Quorn, which the patient had eaten an hour earlier. Scientists' tests showed Quorn to be the only food to which the patient had an allergic reaction. A spokesperson for the Food Standards Agency stated that an allergy was not surprising because of the high protein content. Former FSA director Jon Bell responded in defence of Quorn stating that several commonly consumed foods and food ingredients have a much higher intolerance level than Quorn, such as soya. While adverse reactions were reported for one in 146,000 people who ate Quorn, this rose to one in 35 who ate shellfish and one in 350 who ate soya.
In the European Union, patents expire after 20 years from their filing date. Since the first patent application was filed in 1985, the mycoprotein patents had already expired in 2010 in all EU countries. Now anyone can legally produce mycoprotein products using the previously patented processes (but using other brand names, because Marlow Foods maintains ownership of the Quorn brand name). On 14 March 2011, CEO Kevin Brennan said in an interview: "Some patents surrounding the core technology have expired, but the product uses a peculiar fermentation method, and we have 30-plus years' experience in perfecting this on site to produce the product better and at a lower cost. Huge related costs include £30m cost for a fermentation tower and related equipment, so you can't simply look at a patent and say 'there you go'."
In late 2011, the first vegan Quorn product was released, called the Quorn Vegan Burger, available initially only in the US. Following strong sales of the product and increasing demand from the UK market, Quorn Foods UK Marketing Director Chris Wragg announced that they are now developing and testing a line of vegan products for the UK market. The company said it was also reducing its use of eggs overall, using 3.5 million fewer eggs since 2010. The first range of vegan Quorn in the UK, of which there are currently only six such products, was launched in October 2015.