Food · Vegetables · 菌菇
Mushrooms
不是植物也不是动物, 是真菌 · 热量极低 · 紫外线照射把麦角固醇变成维生素 D2 · 谷氨酸鲜味可少放盐 · 大多数要做熟
Story path
- 1What is a mushroom · neither plant nor animalWhat is a mushroom · neither plant nor animal
- 2Rich in · vitamin D made by UV lightRich in · vitamin D made by UV light
- 3Where umami comes from · cut salt with mushroomsWhere umami comes from · cut salt with mushrooms
- 4Choose · cook · cook them, and wild-mushroom riskChoose · cook · cook them, and wild-mushroom risk
Chapter 1
What is a mushroom · neither plant nor animal
What is a mushroom · neither plant nor animal
A mushroom looks like a vegetable and sits in the produce aisle, but it is neither plant nor animal — it is a fungus, in its own biological kingdom.
This is not just trivia. It explains much of what makes mushrooms unusual: they don't grow by photosynthesis but by breaking down organic matter for energy; their cell walls are chitin, not plant cellulose. The later scenes — vitamin D, umami, needing to be cooked — all trace back to 'it's a fungus'.
Common kinds include button/cremini/portobello (the same species at different maturity), shiitake (more savory when dried), oyster, enoki, and king oyster.
This is not just trivia. It explains much of what makes mushrooms unusual: they don't grow by photosynthesis but by breaking down organic matter for energy; their cell walls are chitin, not plant cellulose. The later scenes — vitamin D, umami, needing to be cooked — all trace back to 'it's a fungus'.
Common kinds include button/cremini/portobello (the same species at different maturity), shiitake (more savory when dried), oyster, enoki, and king oyster.
Chapter 2
Rich in · vitamin D made by UV light
Rich in · vitamin D made by UV light
This is the scene to remember, and a neat mechanism. Mushrooms are rich in a molecule called ergosterol, a building block of the fungal membrane. When UVB light hits ergosterol, a photochemical reaction converts it into vitamin D2 (ergocalciferol) — the same class of reaction as sunlight turning 7-dehydrocholesterol into vitamin D3 in human skin.
The key is whether it has seen light: mushrooms grown in dark sheds are low in vitamin D, while sun-exposed or UV-treated mushrooms can reach 10 µg of vitamin D2 per 100 g or more. That makes mushrooms one of the few non-animal vitamin D sources, valuable especially for people who don't eat animal foods (dive: vitamin-d).
Other highlights: riboflavin (riboflavin-b2), niacin (B3) and pantothenic acid (B5), selenium (selenium), and copper (copper).
Mushrooms are also high in ergothioneine — an antioxidant the body cannot make and must get from food (mainly fungi), which some researchers call a possible 'longevity vitamin'. Current evidence is mostly cellular and animal, lacking large human trials, so we file it under 'worth watching, not yet settled', without overselling.
The key is whether it has seen light: mushrooms grown in dark sheds are low in vitamin D, while sun-exposed or UV-treated mushrooms can reach 10 µg of vitamin D2 per 100 g or more. That makes mushrooms one of the few non-animal vitamin D sources, valuable especially for people who don't eat animal foods (dive: vitamin-d).
Other highlights: riboflavin (riboflavin-b2), niacin (B3) and pantothenic acid (B5), selenium (selenium), and copper (copper).
Mushrooms are also high in ergothioneine — an antioxidant the body cannot make and must get from food (mainly fungi), which some researchers call a possible 'longevity vitamin'. Current evidence is mostly cellular and animal, lacking large human trials, so we file it under 'worth watching, not yet settled', without overselling.
Chapter 3
Where umami comes from · cut salt with mushrooms
Where umami comes from · cut salt with mushrooms
That savory 'umami' hit from mushrooms is not imagination — it has a chemical basis. Mushrooms are naturally high in free glutamate, the source of umami, the fifth basic taste. Dried shiitake also carry a nucleotide called guanylate (GMP); paired with glutamate, umami is amplified well beyond simple addition. That's why a few dried shiitake make a dish taste 'finished' almost instantly.
The practical payoff: umami can partly stand in for the satisfaction salt provides. Using mushrooms — especially dried or as powder — to build savoriness often keeps a dish full-flavored with less added salt. For anyone watching sodium, that's a way to eat well without leaning on heavy salt.
One clarification: the glutamate in mushrooms is the same molecule as the glutamate in MSG, and the body handles them identically. So 'natural umami vs MSG' is not a chemical hierarchy. The difference is only whether you eat the whole mushroom — fiber, B vitamins, and minerals included.
The practical payoff: umami can partly stand in for the satisfaction salt provides. Using mushrooms — especially dried or as powder — to build savoriness often keeps a dish full-flavored with less added salt. For anyone watching sodium, that's a way to eat well without leaning on heavy salt.
One clarification: the glutamate in mushrooms is the same molecule as the glutamate in MSG, and the body handles them identically. So 'natural umami vs MSG' is not a chemical hierarchy. The difference is only whether you eat the whole mushroom — fiber, B vitamins, and minerals included.
Chapter 4
Choose · cook · cook them, and wild-mushroom risk
Choose · cook · cook them, and wild-mushroom risk
Choosing: pick firm, dry caps with no slime or dark spots. For vitamin D, favor ones labeled 'UV-treated / high in vitamin D', or sun them yourself. Dried shiitake have the deepest umami.
Cooking: mushrooms release a lot of water, so for a browned sear don't crowd the pan or salt too early — let the water cook off first. Don't discard the soaking water from dried mushrooms; that's where the umami lives. Most edible mushrooms are best cooked: the chitin cell wall digests better with heat, and raw white mushrooms contain a natural compound called agaritine — everyday amounts pose little risk, and cooking lowers it markedly.
One firm caveat: all of the above is about edible mushrooms from proper suppliers. Wild foraged mushrooms are a different matter entirely — some highly toxic species closely resemble edible ones and can be fatal. Never forage and eat on your own judgment.
How much: mushrooms are very low in calories with nothing that needs limiting, so eat them freely. Their best role is supporting: adding umami, bulk, and a little vitamin D and B vitamins to the plate. For personal medical questions, consult a doctor.
Cooking: mushrooms release a lot of water, so for a browned sear don't crowd the pan or salt too early — let the water cook off first. Don't discard the soaking water from dried mushrooms; that's where the umami lives. Most edible mushrooms are best cooked: the chitin cell wall digests better with heat, and raw white mushrooms contain a natural compound called agaritine — everyday amounts pose little risk, and cooking lowers it markedly.
One firm caveat: all of the above is about edible mushrooms from proper suppliers. Wild foraged mushrooms are a different matter entirely — some highly toxic species closely resemble edible ones and can be fatal. Never forage and eat on your own judgment.
How much: mushrooms are very low in calories with nothing that needs limiting, so eat them freely. Their best role is supporting: adding umami, bulk, and a little vitamin D and B vitamins to the plate. For personal medical questions, consult a doctor.