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Comment by chasil | Hacker News Reader

Firstly, I have read in the past that mushrooms must be boiled before eating to remove toxins. Is this true for the subject of the article, aspergillus oryzae?

Secondly, I have heard that mushrooms are relatively poor for nutritional content, excepting B vitamins. Will there be an enormous amount of nutrition to add to make this viable?

Proof for first point: "Even the cultivated A. bisporus contains small amounts of hydrazines, the most abundant of which is agaritine (a mycotoxin and carcinogen). However, the hydrazines are destroyed by moderate heat when cooking."

Proof for second point: "Riboflavin (B2) 42% 0.5 mg, Pantothenic acid (B5) 30% 1.5 mg" - all other parameters on the wiki under 20%.

https://en.m.wikipedia.org/wiki/Mushroom

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> Firstly, I have read in the past that mushrooms must be boiled before eating to remove toxins.

Not sure where you read that. Some mushrooms can be eaten raw. Some should not be eaten raw, but can be eaten cooked. _Many cannot be eaten even cooked, and may kill you if you try._

The article’s generally talking about single-cell fungus, not mushrooms, in any case. As a concept, mycoprotein for food has been around in a while; notably quorn showed up in 1985.

Please see the quote from the wiki on hydrazines. Sorry if I edited that in after you read my post, it took me a moment to locate.

The offending hydrazine:

> Although recognized as an experimental carcinogen when used in high laboratory doses, there is inadequate evidence to classify Agaritine as carcinogenic to humans in amounts ingested from consuming mushrooms

I mean, if you wanted to be ultra-cautious you might avoid it, but it’s IARC Group 3. Unless you have a _very_ carefully controlled diet, it’s should probably not be high on your list of concerns, carcinogen-wise.

Thanks, that does put it into perspective.

That said, raw mushrooms don’t taste great anyway, so… I’d recommend frying them, and skipping the hydrazine issue altogether.

Says you - personally I love raw chestnut mushrooms, finely sliced.

YMMV as is often said here.

For context, that puts it in the same group as coffee, tea and saccharin, so not exactly something to write home about.

Being in the same "group" doesn't mean it's healthy to eat long term. There need to be randomized double blind controlled trials and warning labels on synthetic foods.

Things get put in this group when the trials (generally on animals; you’re not going to get go ahead for trials of possible carcinogens on humans, generally) show inadequate evidence of carcinogenicity. Next group up is where there’s some, but ambiguous evidence on animals. For reference, agaratine is in group 3; red meat is in 2A, _two_ groups up, and most people are okay with eating that.

> warning labels on synthetic foods.

We’re talking about mushrooms here; mushrooms aren’t synthetic.

No, we're not talking about mushrooms. We're talking about genetically altered fungi.

This thread was talking about actual mushrooms. The genetically modified fungus product doesn’t contain hydrazines, I don’t think?

It's about genetically modified Aspergillus oryzae, or koji mold.

I don't know about saccharin, but tea is known to block iron absorption substantially, and coffee reduces cerebral blood flow (CBF) by virtue of its high caffeine content. Those are just two negative, non-trivial effects coming from those beverages.

This is a good example, albeit a bit sad, of how far detached much of modern society is from our roots. In communities where foraging is common, you learn about these topics as a child and the knowledge is passed down from generation to generation. Many mushrooms are edible, some specifically prepared, some raw, and some are even considered superfoods (!). Mushrooms are very much the trickster though, many of them interchangeably similar in appearance, and for the uninitiated it can be easy to mix up safe ones with dangerous ones.

People these days don't have to scrounge around in the dirt to fend off starvation. Truly sad.

Foraging is not just done to fend off starvation: it is a fun activity for the family that can net you some absolutely delicious foods, and is massively popular in a lot of developed countries - eg: the Nordic countries.

Nothing beats getting a metric shit tonne of chanterelles or similar for free after a nice days exercise in the outdoors.

People who want to do it for fun still do, but most people gave it up as soon as they could.

I don't think that's really true. Nordic countries are full of people who forage and it's not like they need to do it to get by.

As an equally sad counterpoint, if we had 7 billion people out there foraging the countryside would be stripped bare, wild animals driven further from human inhabited areas, and untold habitats would be degraded from all the wandering and poking around.

Don't get me wrong it's a great hobby, but this isn't something that would heal all social ills if we somehow got everybody or near everybody out doing it.

Regarding the nutritional value of mushrooms, a few counterpoints. Firstly, you are only looking at a single variety of mushroom (cremini).

Second, 7% manganese, 17% phosphorus, 15% potassium, and 12% zinc per 3.5oz serving representing 22 calories (or ~1/100 of your daily caloric intake) is nothing to sneeze at.

Go check out 100g servings of various other veggies to get a baseline. It is also likely that these nutrients are far more bioavailable in mushrooms than they are in, for instance, brassica veggies, due to lack of phytates and other uptake inhibiting molecules (so called "anti-nutrients").

FYI, 3.5oz of mushrooms will cook down into less than 1/4 cup, so if you desire, you can eat substantially more than this incorporated into a dish without it necessarily overpowering flavor or texture.

Finally, mushrooms are chock full of other hugely beneficial (but under-studied) dietary compounds such as beta-glycans, triterpenoids, ergosterol, and all manner of immune-modulating tryptophan metabolites such as indole-3-proprionic acid.

This is a fungus, not really a mushroom. It does not need to be boiled to remove toxins. It's widely used in multiple cuisines.

Grocery store mushrooms don't need to be boiled. If you're dealing with mushrooms and don't know whether they should be boiled, play it safe and don't eat them or serve them.

Is there a wiki with nutritional content, similar to the mushroom wiki that I posted?

The sidebar there has daily percentages, and the only entries above 20% are B vitamins.

Do you have a similar RDA analysis for this fungus?

This appears to be the wiki for the subject of the article:

https://en.wikipedia.org/wiki/Aspergillus_oryzae

Fungi contain a large amount of nucleic acid (8–25%), most of which is ribonucleic acid (RNA). In order to reduce the damage on human health, fungal proteins must be processed in a certain way to reduce the content of RNA (to less than 2%), and decrease the risk of gout. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10742821/

Aspergillus oryzae (koji) is eaten raw in Japan, every day, since a long time ago. It's used to make miso. When making miso soup from raw miso (which is made using raw koji), you shouldn't bring the soup to a boil after putting in the miso in order to preserve the positive health effects.

Koji is relatively well-known even outside of Japan these days I believe, even Fedora's build system is named after it.

It's very common in the US to eat the common button mushrooms found in stores, Agaricus bisporus, raw.

Lots of people do question it.

On the second point, if you compare to chicken https://en.wikipedia.org/wiki/Chicken_as_food which has nothing above 20% of RDA per 100g, mushrooms suddenly don't look so bad. (Though it does make me wonder how complete the nutrient tables on Wikipedia are.)

> an enormous amount of nutrition

Seems like a product that tasted mostly like a burger or was at least "meaty" and "tasty" would also be valuable. Generally I feel like I'm getting more than enough nutrition (i.e. calories and stuff)

I am not a nutritionist, but the base wiki for mushrooms says that the only RDA over 20% are B vitamins.

I realize that the subject fungus, aspergillus oryzae, is not a mushroom. They are, however, related.

I wonder if anything with a statistically similar nutritional profile can satiate hunger cravings. That would be a surprise.

> I realize that the subject fungus, aspergillus oryzae, is not a mushroom. They are, however, related.

Brewer's yeast is also related, and it's chock-full of B vitamins (other than B12, which is pretty scarce in anything other than animal tissue). Also protein.

It would be interesting to see the baseline nutritional content of aspergillus oryzae, so we know what must be added.

Due to conventional agricultural practices ie pesti/herbicides, animals have to be fed B12 to contain any. After learning that i stopped eating meat and started taking B12.

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