Fried quorn. Quorn is a mycoprotein, a type of protein produced from a fungus. Quorn is produced from the fermentation of the fungus Fusarium graminearum. It was developed as an alternative to meat for use in vegetarian diets. Quorn is the brand name used by Marlow Foods Limited for this foodstuff. The mycoprotein can be flavoured and shaped to imitate various meats.