This was accurately fixed. Freezing definitely kills most types of bacteria
https://ask.usda.gov/s/article/Does-freezing-food-kill-bacte...
As bacterias are cells with membranes in principle they are killed when frozen, so far, so good...
... but this is just the general case. Not all bacterias have being created equal and there are thousands of species.
Some are extremophiles and store sugar or other substances that act as an antifreeze, so can decrease the temperature of freezing and remain "liquid" under zero point. They can stand much lower temperatures before being killed (by freezing). Is just that they are killed at -25C instead -5C, but the killer is still a tiny ice dagger.
And some bacteria have evolved an outer protective gelatinous capsule, made partially with "sugar", that is not easy to pierce, so they can alter their osmotic pressure and stand more osmotic stress.
And finally, some will just die, but not before creating a inner spore devoid of water that can stand the cold or dry until rehydrated. No water, no ice.
https://www.gov.mb.ca/health/publichealth/environmentalhealt...
"Parasite Destruction for Raw Fish: Seafood products to be served raw must: Have been frozen at a temperature of –20°C (-4°F) for 7 days or below –35°C (-31°F) for 15 hours, to destroy parasites that might be present."
But if tomorrow we would found a suitable antifreeze in some obscure creature that is not rejected by the body and does not damage the cells, this is a game changer. To be able to put the body just about to freeze but not further... that would be awesome.
Would be a key to 1-hibernation and long term space travel, 2-increase life expectancy slowing the metabolism and this mean slowing cancer also, 3-increase in the range of temperatures that humans can stand without suffering chill burning and losing fingers.
De-thawing would be still a brutal process. Not all cells would survive.
My understanding was that ice crystal length was also related to time taken to freeze.
IE freezing faster produced smaller crystals that don't then damage the cells so much.
We have a liquid nitrogen icecream shop that exploits the shorter crystal length to make "creamier" icecream while you wait. Not exactly how I'd want my brain frozen but hopefully the cryogenic experts know a way.
But it really does need to be handled appropriately. For example, while you can put it in a simple thermos flask you shouldn't be in small enclosed spaces with it. IE elevator/car.
The liquid expands to quite a lot of gas and might force out all the standard air taking the oxygen with it.
But mainly it is about 'freeze burns'.
My wife(science lab manager) cringes at the lack of safety glasses and gloves at the ice cream shop.
They plonk ingredients into an open top mixer/blender and then pour the liquid nitrogen in while it is running!
Edit: tweaked wording.
"Not all bacteria are created equal ..."
Trivia: Spanish would distinguish between "una bacteria" (one bacterium) feminine noun in Spanish so it ends in "a", and between "una colonia de bacterias" (a colony of bacteria). Bacterias would be the correct plural in Spanish. English works a little different here.
The exceptions are things like
* mixed modern coinages (e.g. "television", a Latin suffix with a Greek prefix),
* divergent modern coinages ("bicycle" is not Greek "κύκλος" nor Latin "cyclus", and was taken from French),
* words not attested in the plural in the original language (e.g. "virus", only attested in the singular),
* words not actually singular in the original language (e.g. "ignoramus" is a verb in Latin, first person plural), and
* things that have since diverged (e.g. "hippopotamus", where "ποταμός" meaning "river" is "-ός" and hence "ποταμοι" in Greek but the word that English has came via Late Latin).
English generally pluralizes these things the Germanic way with "-es"/"-s", although pluralizing "hippopotami" as Latin is well attested and "bicycles" is the French plural.
Getting English speakers to remember "spaghetto", "panino", "confetto", "graffito", "paparazzo", or even "die" (singular of "dice") is somewhat hard. (-:
https://cooking.stackexchange.com/questions/76455/in-the-usa...
Most red meats sit out for a bit, either wet or dry aged, which enhances the flavors. Fish will need to be frozen or cooked to a safe temperature.
I have eaten raw skipjack tuna that I caught myself and never froze. Tuna, as far as I know, has very little risk of parasitic infection. It was delicious.
https://pubmed.ncbi.nlm.nih.gov/25461601/
https://www.healthline.com/nutrition/raw-tuna#parasites
You got lucky, and yes, it is delicious, but you're definitely playing health roulette.
The real problem with tuna is that is an accumulator of nasty substances like mercury and also fast and nomadic by nature. This means that you can find Japanese tuna in California, or the Mediterranean, and this can be a problem.
Most of the fish parasites just turn into food after being cooked. Our stomach acid will not care. The number of marine fish parasites able to harm humans is very small. We are too hot for them. I could count all the major types with my fingers (I was surprised to learn (here) that Kudoa is a new problem in any case).
The catch, for anyone who's never tried it, is that you're not just eating raw meat, you're eating finely chopped raw meat and butter and egg yolk and onion and toast etc.
Now I'm wondering what animals we do eat raw in America other than oysters and (if you know where to go) other sea creatures that might be alive when served.
It was delicious...but if I ate it too fast I would gag.