Abstract: Mushrooms are highly nutritious food sources, which can be cultivated on cheap and usually readily available raw materials. China is the world’s major producer and consumer of mushrooms, and output in 2011 (22.6 million tons) accounted for more than 75% of the global total. A major obstacle to the marketability of white mushrooms (e.g. Agaricus bisporus) is browning of the fruit body that occurs after harvesting. Illegal use of fluorescent whitening agents (FWAs) to offset the adverse effects of browning has now been reduced to very few sporadic cases as a result of measures introduced by the Chinese Ministry of Agriculture.