Agaricus bisporus is an edible basidiomycete mushroom native to grasslands in Europe and North America. It has two color states while immature—white and brown—both of which have various names. In recent years, growers found that if they allowed the crimini to grow far beyond the normal size with the cap spreading to expose all the gills, it became the size of a hamburger bun, thus spurring the veggie burger craze. The name marketers agreed on was portobello mushroom (also portabella or portobella).
When immature and white, this mushroom may be known as common mushroom, button mushroom, cultivated mushroom, table mushroom, and champignon mushroom. When immature and brown, it may be known variously as Swiss brown mushroom, Roman brown mushroom, Italian brown mushroom, cremini/crimini mushroom, or chestnut mushroom.
A. bisporus is cultivated in more than seventy countries, and is one of the most commonly and widely consumed mushrooms in the world.
The earliest scientific description of the commercial cultivation of A. bisporus was made by French botanist Joseph Pitton de Tournefort in 1707. French agriculturist Olivier de Serres noted that transplanting mushroom mycelia would lead to the propagation of more mushrooms.
Originally, cultivation was unreliable as mushroom growers would watch for good flushes of mushrooms in fields before digging up the mycelium and replanting them in beds of composted manure or inoculating 'bricks' of compressed litter, loam, and manure. Spawn collected this way contained pathogens and crops commonly would be infected or not grow at all. In 1893, sterilized, or pure culture, spawn was discovered and produced by the Pasteur Institute in Paris, for cultivation on composted horse manure.
Today's commercial variety of the common mushroom originally was a light brown color. In 1926, a Pennsylvania mushroom farmer found a clump of common mushrooms with white caps in his mushroom bed. As with the reception of white bread, it was seen as a more attractive food item and became very popular. Similar to the commercial development history of the navel orange and Red Delicious apple, cultures were grown from the mutant individuals, and most of the cream-colored store mushrooms marketed today are products of this 1926 chance natural mutation.
A. bisporus is now cultivated in at least seventy countries throughout the world. Global production in the early 1990s was reported to be more than 1.5 million short tons (1.4 billion kilograms), worth more than US$2 billion.
In a 100-gram serving, raw white mushrooms provide 93 kilojoules (22 kilocalories) of food energy and are an excellent source (> 19% of the Daily Value, DV) of the B vitamins, riboflavin, niacin, and pantothenic acid (table). Fresh mushrooms are also a good source (10–19% DV) of the dietary mineral phosphorus (table).
While fresh A. bisporus only contains 0.2 micrograms (8 IU) of vitamin D as ergocalciferol (vitamin D2), the ergocalciferol content increases substantially after exposure to UV light.
The earliest written record of shiitake cultivation is seen in the Records of Longquan County (龍泉縣志) compiled by He Zhan (何澹) in 1209 during the Southern Song dynasty. The 185-word description of shiitake cultivation from that literature was later crossed-referenced many times and eventually adapted in a book by a Japanese horticulturist Satō Chūryō (佐藤中陵) in 1796, the first book on shiitake cultivation in Japan.
The Japanese cultivated the mushroom by cutting shii trees with axes and placing the logs by trees that were already growing shiitake or contained shiitake spores. Before 1982, the Japan Islands' variety of these mushrooms could only be grown in traditional locations using ancient methods. A 1982 report on the budding and growth of the Japanese variety revealed opportunities for commercial cultivation in the United States.
Shiitake are now widely cultivated all over the world, and contribute about 25% of total yearly production of mushrooms. Commercially, shiitake mushrooms are typically grown in conditions similar to their natural environment on either artificial substrate or hardwood logs, such as oak.
In a 100 gram amount, raw shiitake mushrooms provide 34 calories and are 90% water, 7% carbohydrates, 2% protein and less than 1% fat (table for raw mushrooms). Raw shiitake mushrooms are rich sources (20% or more of the Daily Value, DV) of B vitamins and contain moderate levels of some dietary minerals (table). When dried to about 10% water, the contents of numerous nutrients increase substantially.
Like all mushrooms, shiitakes produce vitamin D2 upon exposure of their internal ergosterol to ultraviolet B (UVB) rays from sunlight or broadband UVB fluorescent tubes.
Fresh and dried shiitake have many uses in the cuisines of East Asia. In Japan, they are served in miso soup, used as the basis for a kind of vegetarian dashi, and as an ingredient in many steamed and simmered dishes. In Chinese cuisine, they are often sautéed in vegetarian dishes such as Buddha's delight.
One type of high-grade shiitake is called donko (冬菇) in Japanese and dōnggū in Chinese, literally "winter mushroom". Another high-grade of mushroom is called huāgū (花菇) in Chinese, literally "flower mushroom", which has a flower-like cracking pattern on the mushroom's upper surface. Both of these are produced at lower temperatures.
Grifola frondosa is a polypore mushroom that grows in clusters at the base of trees, particularly oaks. The mushroom is commonly known among English speakers as hen of the woods, hen-of-the-woods, ram's head and sheep's head. It is typically found in late summer to early autumn. In the United States' supplement market, as well as in Asian grocery stores, the mushroom is known by its Japanese name maitake (舞茸, "dancing mushroom"). Throughout Italian American communities in the northeastern United States, it is commonly known as the signorina mushroom. G. frondosa should not be confused with Laetiporus sulphureus, another edible bracket fungus that is commonly called chicken of the woods or "sulphur shelf". Like all polypores, the fungus becomes inedible when older, because it is then too tough to eat.
The fungus is native to China, the northeastern part of Japan and North America, and is prized in traditional Chinese and Japanese herbology as a medicinal mushroom.
In 2009, a phase I/II human trial, conducted by Memorial Sloan–Kettering Cancer Center, showed maitake could stimulate the immune systems of breast cancer patients. Small experiments with human cancer patients have shown it can stimulate immune system cells, such as NK cells In vitro research has also shown Maitake can stimulate immune system cells. An in vivo experiment showed that it could stimulate both the innate immune system and adaptive immune system.
In vitro research has shown maitake can induce apoptosis in various cancer cell lines, and inhibit the growth of various types of cancer cells. Small studies with human cancer patients revealed that a portion of this mushroom, known as the mitake D-fraction, possesses anticancer activity. In vitro research demonstrated the mushroom has potential antimetastatic properties.
Maitake has a hypoglycemic effect, and may be beneficial for the management of diabetes. It lowers blood sugar because the mushroom naturally contains an alpha glucosidase inhibitor.
This species contains antioxidants and may partially inhibit the enzyme cyclooxygenase. An extract of maitake inhibited angiogenesis via inhibition of the vascular endothelial growth factor.
Lys-N is a unique protease found in maitake. Lys-N is used for proteomics experiments because of its protein cleavage specificity.