FYI!
"Quorn - Production
"Quorn is made from the soil mold Fusarium venenatum strain PTA-2684 (previously misidentified as the parasitic mold Fusarium graminearum). F. venenatum was discovered in the soil of a farm near the town of Marlow in the UK in the 1960s.
"The fungus is grown in continually oxygenated water in large sterile fermentation tanks. During the growth phase glucose is added as a food for the fungus, as are various vitamins and minerals (to improve the food value of the resulting product). The resulting mycoprotein is then extracted and heat-treated to remove excess levels of RNA. Previous attempts at producing such fermented protein foodstuffs were thwarted by excessive levels of DNA or RNA; without the heat treatment, purine, found in nucleic acids, is metabolised producing uric acid, which can lead to gout. [1]
"The product is then dried and mixed with chicken 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) or into chunks (resembling diced chicken breast). In this form Quorn has a light brown colour and a mild flavour vaguely akin to a nutty beef, 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 vegetable protein, dietary fibre, and is low in saturated fat and salt."
from here
also
"Quorn - Controversy
"Its 2002 debut in the United States was more problematic -- the sale of Quorn was contested by The American Mushroom Institute, Gardenburger, and the Center for Science in the Public Interest. They filed complaints with advertising and trading-standards watchdogs in Europe and the USA, claiming that the labelling of Quorn as "mushroom based" was deceptive. The CSPI, observing that while a mushroom is a fungus, fusarium is not a mushroom, and they quipped, "Quorn's fungus is as closely related to mushrooms as humans are to jellyfish."
"CSPI also expressed concern that some proteins present in Quorn could produce unexpected allergic reactions in some consumers, and continues to lobby for its removal from stores on this basis. But as others counter, milk, peanuts, soy, eggs, and many other foods are common allergens (often fatally), setting a precedent that simply being an allergen for some consumers is not a reasonable cause to remove a product from stores. Calling the product "fungus food", CSPI claimed in 2003 that it "sickens 5% of eaters" [2]. The manufacturer disputes the figure, claiming that only 0.0007% (1 in 146,000) suffers adverse reactions. Defenders of Quorn have alleged CSPI may be influenced by large soybean agribusinesses because Quorn would compete most directly with soy based textured vegetable protein.
"Quorn has been criticised by organisations opposed to battery farming, because although it is marketed to vegetarians, some Quorn products contain battery egg, the use of which many vegetarians oppose. For this reason, the Vegetarian Society does not approve these products. However, since 2000, part of the Quorn range has been produced using free-range eggs, including the pieces and mince ingredients."
from the same site. Site itself looks a bit whacko but the info here is taken from an external source and seems sound.