(Tom: I do not possess a microwave so did some research on the data in this video.)
Just watched a video which talked about the substance agaritine which is apparently not good for us and how cooking white button mushrooms removes it but boiling or steaming them leached out beneficial antioxidants like ergothioneine.
The video recommends microwaving but I do not have a microwave. I usually fry my mushrooms in butter. What affect does this have on ergothioneine and agaritine? So I asked ChatGPT the question…
Yes — your usual method of frying white button mushrooms in butter is actually quite a reasonable approach if your aim is to reduce agaritine without throwing away water-soluble compounds. The research is rather more reassuring than the video may have made it sound.
What happens when you fry them?
For white button mushrooms (Agaricus bisporus), the best direct evidence I found is a household-processing study that specifically tested frying in oil and butter.
Frying in butter reduced agaritine by about 35–70%, depending on the cooking conditions.
One experiment found that frying at about 100°C for 5 minutes reduced agaritine by approximately 69% when butter was used.
Very little of the removed agaritine ended up in the cooking fat, suggesting that much of it was degraded rather than simply transferred into the butter.
More recent research also found that all tested heat treatments reduced agaritine, with no toxic degradation products detected in that particular study.
So your frying method is doing a useful job on the agaritine.
But what about ergothioneine?
This is where I would not automatically conclude that microwaving is superior.
Ergothioneine is quite different from agaritine. It is a water-soluble antioxidant, and the major problem with boiling is that compounds can leach out of the mushroom into the cooking water.
If you boil mushrooms and throw away the water, you potentially throw away some of those compounds with it.
Frying has an advantage here: there is little or no water for the water-soluble compounds to leach into.
However, frying isn’t completely benign. Studies of mushroom cooking show that frying can cause greater losses of some nutritional compounds than gentler methods, particularly when temperatures are high.
Importantly, though, I couldn’t find good evidence establishing that ordinary pan-frying destroys a large proportion of ergothioneine specifically in white button mushrooms. The cooking literature tends to measure broader antioxidant activity or groups of compounds rather than giving us a clean “X% of ergothioneine survives frying” figure.
So I’d rank your practical options like this:
| Method | Agaritine | Nutrient Retention |
|---|---|---|
| Raw | Highest | Highest |
| Boiled & water discarded | Much lower | Some water-soluble compounds lost into water |
| Steamed | Reduced | Better than boiling for avoiding leaching |
| Microwaved | Reduced substantially | Generally good overall retention |
| Fried gently in butter | Reduced substantially | Good practical compromise |
| Fried very hot/for a long time | Reduced substantially | Greater heat-related losses |
There is an interesting wrinkle here: a study of white button mushrooms found that phenolic compounds were drastically reduced by boiling, whereas the lack of direct water contact during frying helped prevent that leaching.
What I’d do in your kitchen
I’d keep doing what you’re doing.
I’d use moderate heat rather than extremely high heat, and cook the mushrooms until they are properly cooked and browned but not burnt or excessively dried.
Something like:
Slice, butter in pan, cook on moderate heat until the mushrooms have released their moisture and are nicely browned, eat the mushrooms and butter together.
That gives you three useful things:
Cooking substantially reduces agaritine.
You’re not dumping water containing soluble compounds down the sink.
You’re retaining the compounds that have moved into the butter rather than discarding a cooking liquid.
And there’s one particularly reassuring point about the agaritine issue: the scientific literature does not support the idea that eating normally cooked button mushrooms represents some major established health hazard. Agaritine is a naturally occurring compound of toxicological interest, but its concentration varies considerably and cooking substantially reduces it.
Bottom line: I wouldn’t buy a microwave just for this purpose. Your butter-fried white button mushrooms are a perfectly sensible way of preparing them, and may actually give you a better compromise between reducing agaritine and avoiding the nutrient losses associated with boiling.