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9.2 Types of Mushrooms
Mushrooms can be classified into three groups: the saprophytes, the parasites, and
the mycorrhizae. Most of the gourmet mushrooms are saprophytic (wooddecomposing fungi, which are the premier recyclers on the planet). The enzymes
and acids that they secrete degrade large molecular complexes into simpler compounds. All ecosystems depend on the ability of fungi to decompose the organic
matter of plants; the final result of their activity is the return of carbon, hydrogen,
nitrogen, and minerals to the ecosystem in usable forms. Many saprophytic fungi
can be weakly parasitic in their behavior. Some parasitic mushrooms are edible; the
best known is Armillaria mellea (Stamets 2005). Mycorrhizae are systems of fungal
symbiosis with the roots of plants, where both species benefit. In this case, the plant
receives mainly mineral nutrients and water from the fungus, and the fungus obtains
vitamins and carbohydrates produced by photosynthesis from the plant. It is estimated that a high percentage of terrestrial plants present mycorrhizas on a regular basis.
9.2.1 Saprophytic Mushrooms
Agaricus subrufescens Peck It belongs to the Agaricaceae family of the order
Agaricales of the basidiomycetes (Index Fungorum 2017). This species and others
of the same genus can be found in forests, but more commonly in pastures or roadsides; it is a saprophyte that uses decaying leaves often at the borders between forests and parks (Firenzuoli et al. 2008). It was called the “almond mushroom,”
because of its almond flavor. It is cultivated and consumed in the United States from
the late nineteenth century to the early twentieth century. In 1960, it was discovered
in Brazil and called the “Piedade mushroom” because of the name of the town
where it was found, in the province of São Paulo (Kerrigan 2005).
The champignon mushroom has been produced in a commercial market on a
national scale in Brazil since the early 1990s and has been exported to other countries, currently also grown at industrial level in Japan, China, Taiwan, and Korea. As
substrates for the production of fruiting bodies, it has been used as sugarcane
bagasse, some herbs (Brachiaria spp., Cynodon dactylon, Panicum maximum),
cereal straw (Triticum aestivum, Avena sativa, Oryza sativa), and manure supplemented with nitrogen sources (soy, wheat, cotton flour, urea, ammonium sulfate)
and sources of phosphorus and calcium (Llarena-Hernández et al. 2014). The fruiting bodies of Agaricus subrufescens contain 89–91% water and have high level of
minerals (potassium, phosphorus, calcium, magnesium, and zinc). However, small
amounts of cadmium have been detected (Gyorfi et al. 2010). The polysaccharides
consisted of 57.7% glucose, 27.7% galactose, 7.3% mannose/xylose, and 4% fucose
(Volman et al. 2010).
9 Mushrooms as Edible Foods
9.2 Types of Mushrooms
Mushrooms can be classified into three groups: the saprophytes, the parasites, and
the mycorrhizae. Most of the gourmet mushrooms are saprophytic (wooddecomposing fungi, which are the premier recyclers on the planet). The enzymes
and acids that they secrete degrade large molecular complexes into simpler compounds. All ecosystems depend on the ability of fungi to decompose the organic
matter of plants; the final result of their activity is the return of carbon, hydrogen,
nitrogen, and minerals to the ecosystem in usable forms. Many saprophytic fungi
can be weakly parasitic in their behavior. Some parasitic mushrooms are edible; the
best known is Armillaria mellea (Stamets 2005). Mycorrhizae are systems of fungal
symbiosis with the roots of plants, where both species benefit. In this case, the plant
receives mainly mineral nutrients and water from the fungus, and the fungus obtains
vitamins and carbohydrates produced by photosynthesis from the plant. It is estimated that a high percentage of terrestrial plants present mycorrhizas on a regular basis.
9.2.1 Saprophytic Mushrooms
Agaricus subrufescens Peck It belongs to the Agaricaceae family of the order
Agaricales of the basidiomycetes (Index Fungorum 2017). This species and others
of the same genus can be found in forests, but more commonly in pastures or roadsides; it is a saprophyte that uses decaying leaves often at the borders between forests and parks (Firenzuoli et al. 2008). It was called the “almond mushroom,”
because of its almond flavor. It is cultivated and consumed in the United States from
the late nineteenth century to the early twentieth century. In 1960, it was discovered
in Brazil and called the “Piedade mushroom” because of the name of the town
where it was found, in the province of São Paulo (Kerrigan 2005).
The champignon mushroom has been produced in a commercial market on a
national scale in Brazil since the early 1990s and has been exported to other countries, currently also grown at industrial level in Japan, China, Taiwan, and Korea. As
substrates for the production of fruiting bodies, it has been used as sugarcane
bagasse, some herbs (Brachiaria spp., Cynodon dactylon, Panicum maximum),
cereal straw (Triticum aestivum, Avena sativa, Oryza sativa), and manure supplemented with nitrogen sources (soy, wheat, cotton flour, urea, ammonium sulfate)
and sources of phosphorus and calcium (Llarena-Hernández et al. 2014). The fruiting bodies of Agaricus subrufescens contain 89–91% water and have high level of
minerals (potassium, phosphorus, calcium, magnesium, and zinc). However, small
amounts of cadmium have been detected (Gyorfi et al. 2010). The polysaccharides
consisted of 57.7% glucose, 27.7% galactose, 7.3% mannose/xylose, and 4% fucose
(Volman et al. 2010).
9 Mushrooms as Edible Foods