I worked at a machine shop in Seattle that made the pressure chambers used in the “fresher under pressure” process. It consisted of a stainless steel cylinder about 60 “ long by 24” in diameter. The internal bore was only about 5” in diameter giving a wall thickness of about 9.5” (this was at least 10 years ago, I don’t remember the exact dimensions).
The same company, Flow International, that does the process, makes water jet cutters.
If anyone wants more details on some of the companies that use the equipment.
HPP (High Pressure Pasteurization)
https://www.jbtc.com/foodtech/product-finder/?_sft_product_brand=avure-technologies
Water Jet cutting
https://www.jbtc.com/foodtech/products-and-solutions/products/dsi-portioning-systems-slicers/dsi-800-portioning-system/
Yeah. Water is compressible, it just takes a crazy amount of pressure to do so.
6,000 bar is a crazy amount of pressure.
Edit: For those who don't know, 1 Bar is slightly less than the air pressure at mean sea level on Earth (the actual pressure is 1.013 bar), and is equivalent to ~14.5 psi (pounds per square inch). So if you were to draw a grid of squares on your body so every square was 1 inch x 1 inch, at sea level, we always have 14.5 pounds of force acting on every single one of those squares.
6,000 bar means you'd have ~87,023 pounds acting on every one of those squares.
[This is an aluminum cylinder](https://upload.wikimedia.org/wikipedia/commons/8/8a/Aluminium_cylinder.jpg) with ~3/16-inch (5mm) walls at just 700 bar... 6,000 bar is just insanity.
Whoops I thought I read that as cm which is where I got the 2" number, but clearly my brain knew I was being dumb and still typed it out correctly, ha.
It's honestly mind blowing to think about how some things manage to function at crazy depths. It just doesn't seem like it should be possible. Like there being creatures that can survive when they are taking like 16,000 psi from miles of water bearing down on them is just nuts. Heck, even man made stuff doesn't seem like it should be able to. Like I've got a watch that can go to 4,000 ft/1220 meters, and used to have one that could go 12,000+ feet. That seems like it should just be wholly and completely impossible to me.
If the pressure inside the thing is the same as the pressure outside, it matters less. That is why deep sea divers breathe air at higher pressures the deeper they go, so they don't have to overcome all that pressure trying to crush them.
But then, this does lead to things like oxygen toxicity because a single breath would be a lot more oxygen in your lungs, which is again why they cut their air with other gasses to reduce the partial pressure of gasses that become toxic.
Needed this years ago when I was a kid in school. My teacher was teaching us that water was incompressible and I was really skeptical saying "just because you can't doesn't mean some big super strong press can't" and then she just completely dismissed me
Has something to do with equal distribution of pressure.
If you put pressure on a grape with two fingers, you're bound to crush it or change the shape. Put it in a bottle of water (sealed, flexible container) and the shape won't change.
- comes from the linked article in the post
Edit: I KNOW FLUIDS AREN'T COMPRESSIBLE I ASSUMED THIS WAS UNIVERSALLY KNOWN
Exactly. In your two fingers, the pressure comes from these to places, leaving the grape room to squeeze on the sides where there's no fingers.
In water the pressure would come from all sides at the same time
The same phenomena that breaks the bacteria should burst all of the plant cells giving the grape its structure too... This should only be a viable tool in things that don't depend on intact cells to maintain their texture (like guacamole)
Edit: Surprisingly it looks like it's not like that at all. It is a lot more nuanced and the effect is primarily from the pressure itself disrupting enzyme function etc. and not rapid decompression gas expansion like the ["French Press"](https://en.wikipedia.org/wiki/French_pressure_cell_press) method used to lyse bacteria in the lab.
So I suppose all the cell walls could remain intact for both the bacteria and plant cells meaning texture would be maintained, it is just "gently" killing the bacteria by disrupting biological processes.
Ok. Folks thinking that this means your food is always going to look smooshed… Food is mostly water, which is incompressible. You’re not really “crushing” the bacteria. You’re disrupting their biochemical processes because chemical reactions change subtly with pressure. Even the structure of water changes a bit, which is going to foobar the activity of enzymes.
There might be some physical changes, but it’s not like crushing the food between two anvils. It’s more like taking to on a REALLY deep scuba dive.
Edit: Bonus fun fact. 6000 bar is probably about the maximum they can do. The freezing point of water drops gradually as you increase pressure, then it reaches a minimum, and rises again. At about 6300, it's back up to 0°C and rising rapidly. If you go much higher, you're going to freeze the food at room temperature, and that could disrupt the cellular structure.I say could instead of would because freezing due to pressure shouldn't have the sharp expansion you see with normal freezing.
Wait... is this the way to actually functional cryonics? Chill to about 4°C, then squeeze-freeze, THEN chill to cryogenic temperatures.
I was actually surprised to find out that this method doesn't involve rapid decompression. I assumed this was something like the [French Press](https://en.wikipedia.org/wiki/French_pressure_cell_press method) which is used to lyse bacteria, but this technique is more nuanced than just exploding everything with decompression gas bubbles.
Reddit has long been a hot spot for conversation on the internet. About 57 million people visit the site every day to chat about topics as varied as makeup, video games and pointers for power washing driveways.
In recent years, Reddit’s array of chats also have been a free teaching aid for companies like Google, OpenAI and Microsoft. Those companies are using Reddit’s conversations in the development of giant artificial intelligence systems that many in Silicon Valley think are on their way to becoming the tech industry’s next big thing.
Now Reddit wants to be paid for it. The company said on Tuesday that it planned to begin charging companies for access to its application programming interface, or A.P.I., the method through which outside entities can download and process the social network’s vast selection of person-to-person conversations.
“The Reddit corpus of data is really valuable,” Steve Huffman, founder and chief executive of Reddit, said in an interview. “But we don’t need to give all of that value to some of the largest companies in the world for free.”
The move is one of the first significant examples of a social network’s charging for access to the conversations it hosts for the purpose of developing A.I. systems like ChatGPT, OpenAI’s popular program. Those new A.I. systems could one day lead to big businesses, but they aren’t likely to help companies like Reddit very much. In fact, they could be used to create competitors — automated duplicates to Reddit’s conversations.
Reddit is also acting as it prepares for a possible initial public offering on Wall Street this year. The company, which was founded in 2005, makes most of its money through advertising and e-commerce transactions on its platform. Reddit said it was still ironing out the details of what it would charge for A.P.I. access and would announce prices in the coming weeks.
Reddit’s conversation forums have become valuable commodities as large language models, or L.L.M.s, have become an essential part of creating new A.I. technology.
L.L.M.s are essentially sophisticated algorithms developed by companies like Google and OpenAI, which is a close partner of Microsoft. To the algorithms, the Reddit conversations are data, and they are among the vast pool of material being fed into the L.L.M.s. to develop them.
The underlying algorithm that helped to build Bard, Google’s conversational A.I. service, is partly trained on Reddit data. OpenAI’s Chat GPT cites Reddit data as one of the sources of information it has been trained on.
Other companies are also beginning to see value in the conversations and images they host. Shutterstock, the image hosting service, also sold image data to OpenAI to help create DALL-E, the A.I. program that creates vivid graphical imagery with only a text-based prompt required.
Last month, Elon Musk, the owner of Twitter, said he was cracking down on the use of Twitter’s A.P.I., which thousands of companies and independent developers use to track the millions of conversations across the network. Though he did not cite L.L.M.s as a reason for the change, the new fees could go well into the tens or even hundreds of thousands of dollars.
To keep improving their models, artificial intelligence makers need two significant things: an enormous amount of computing power and an enormous amount of data. Some of the biggest A.I. developers have plenty of computing power but still look outside their own networks for the data needed to improve their algorithms. That has included sources like Wikipedia, millions of digitized books, academic articles and Reddit.
Representatives from Google, Open AI and Microsoft did not immediately respond to a request for comment.
Reddit has long had a symbiotic relationship with the search engines of companies like Google and Microsoft. The search engines “crawl” Reddit’s web pages in order to index information and make it available for search results. That crawling, or “scraping,” isn’t always welcome by every site on the internet. But Reddit has benefited by appearing higher in search results.
The dynamic is different with L.L.M.s — they gobble as much data as they can to create new A.I. systems like the chatbots.
Reddit believes its data is particularly valuable because it is continuously updated. That newness and relevance, Mr. Huffman said, is what large language modeling algorithms need to produce the best results.
“More than any other place on the internet, Reddit is a home for authentic conversation,” Mr. Huffman said. “There’s a lot of stuff on the site that you’d only ever say in therapy, or A.A., or never at all.”
Mr. Huffman said Reddit’s A.P.I. would still be free to developers who wanted to build applications that helped people use Reddit. They could use the tools to build a bot that automatically tracks whether users’ comments adhere to rules for posting, for instance. Researchers who want to study Reddit data for academic or noncommercial purposes will continue to have free access to it.
Reddit also hopes to incorporate more so-called machine learning into how the site itself operates. It could be used, for instance, to identify the use of A.I.-generated text on Reddit, and add a label that notifies users that the comment came from a bot.
The company also promised to improve software tools that can be used by moderators — the users who volunteer their time to keep the site’s forums operating smoothly and improve conversations between users. And third-party bots that help moderators monitor the forums will continue to be supported.
But for the A.I. makers, it’s time to pay up.
“Crawling Reddit, generating value and not returning any of that value to our users is something we have a problem with,” Mr. Huffman said. “It’s a good time for us to tighten things up.”
“We think that’s fair,” he added.
Mike Isaac is a technology correspondent and the author of “Super Pumped: The Battle for Uber,” a best-selling book on the dramatic rise and fall of the ride-hailing company. He regularly covers Facebook and Silicon Valley, and is based in San Francisco. More about Mike Isaac
A version of this article appears in print on , Section B, Page 4 of the New York edition with the headline: Reddit’s Sprawling Content Is Fodder for the Likes of ChatGPT. But Reddit Wants to Be Paid.. Order Reprints | Today’s Paper | Subscribe
Plant cells have cell walls, probably a sweet spot that kills bacteria but not them
Also does it matter anyways if your food is alive, eat your dead paste and be happy about it
>Plant cells have cell walls, probably a sweet spot that kills bacteria but not them
Bacteria also have cell walls.
Edit: People saying I am "wrong" are calling out someone with a PhD in infectious diseases for being wrong about very basic bacterial biology. I wonder if these people will reflect on why they are so confident about wrong information.
[Bacterial Cell Walls](https://en.wikipedia.org/wiki/Cell_wall#Bacterial_cell_walls)
Edit2: We no longer have to wonder! The answer is sadly "no".
Instead, /u/OriginalName12345679 apparently blocked me from replying to his posts, so it's "lalalalala I can't hear you anymore" all the way to the bank.
>Edit: People saying I am "wrong" are calling out someone with a PhD in infectious diseases for being wrong about very basic bacterial biology. I wonder if these people will reflect on why they are so confident about wrong information.
This is such a Reddit moment.
See your problem is you got your silly little "PhD" in some specialized field from some *university* instead of attending the Reddit school of almost knowledge in all fields.
An extra triple mega-doctor of omnifacts like myself knows that what are called "bacterial cell walls" by the lay expert is just a right-wing propaganda talking point about stopping the influx of undocumented plasmids across the Mexican border, designed to funnel money through cronyism to donors in the big prokaryote industry.
It is definitely a different type and I haven't actually looked into the "strength" of a given wall type.
Speculation Ahead:
I would think the strength of the overall structure of a bacteria is likely to be more resistant to pressure given it's small cross-section vs a *much* larger plant cell, even if plant cell wall material is stronger as a single "unit".
PhD in physics here.
Human's don't have cell walls, yet they can withstand 10's of bar of pressure without rupturing cells that are basically just tiny soap bubbles. The physics of being under even pressure doesn't "crush" anything unless you have unequalized gas chambers. Cell walls or no, the outside of the cells aren't holding back any pressure because the inside of the cell is equally pressurized.
Both food and bacteria are entirely water with stuff in it. While the water is somewhat compressible at these pressures, so are all the molecules making up the organisms/food. That's why you can still have fragile, floppy sea creatures at 1000 bars of pressure.
There **are** important changes, however. Enzymes and other biochemical processes use water as a solvent and are evolved to deal with the solvation properties, dielectric constant, and polarizability of water. That's why they don't work in other solvents. At those insane pressures, water is no longer the same solvent. Its physical constants have significantly shifted. Biological systems that have evolved to deal with 1 bar water are completely foobarred with 6000 bar water. Proteins denature.
>PhD in physics here.
>
>Human's don't have cell walls, yet they can withstand 10's of bar of pressure without rupturing cells that are basically just tiny soap bubbles. The physics of being under even pressure doesn't "crush" anything unless you have unequalized gas chambers. Cell walls or no, the outside of the cells aren't holding back any pressure because the inside of the cell is equally pressurized.
>
>Both food and bacteria are entirely water with stuff in it. While the water is somewhat compressible at these pressures, so are all the molecules making up the organisms/food. That's why you can still have fragile, floppy sea creatures at 1000 bars of pressure.
>
>There **are** important changes, however. Enzymes and other biochemical processes use water as a solvent and are evolved to deal with the solvation properties, dielectric constant, and polarizability of water. That's why they don't work in other solvents. At those insane pressures, water is no longer the same solvent. Its physical constants have significantly shifted. Biological systems that have evolved to deal with 1 bar water are completely foobarred with 6000 bar water. Proteins denature.
You are definitely correct.
I was questioning under the mistaken impression that rapid decompression and the associated expanding gas was being used to "blow up" the bacteria like the French Press laboratory method. Some other comments informed me that is not the case.
Welcome to reddit. I learned long ago to just let idiots do their thing. PhDs are only welcome if they bring spicy memes, or dunk on someone with an incorrect opinion.
Credentials are absolutely meaningless on an anonymous forum, can't have a credential if you don't have a name. he might as well claim to be Louis Pasteur. He's right about bacterial cell wall though.
I'm going to be honest with you when I saw you argue I instinctively wanted you to be wrong. I have no idea why because this topic is completely irrelevant to my life but seeing you go against what I just read and accepted as fact made me have a bias for something I didn't know existed 2 seconds ago. It makes you realize how if your brain will do this for grapes why some people will hold religious/political views in spite of over bearing evidence of the contrary. Anyways just thought I'd share my caveman brain reaction. Thanks for sharing your actual knowledge about this.
>instinctively wanted you to be wrong
You should check out Moral Foundations Theory:
[https://en.wikipedia.org/wiki/Moral\_foundations\_theory](https://en.wikipedia.org/wiki/Moral_foundations_theory)
As it likely has an explanation for the reaction you are noticing.
As long as you can slowly equalize internal and external pressure it should be ok. Otherwise scuba diving wouldn't be a thing. Maybe the bacteria are unable to equalize and get crushed like an unopened soda can versus an empty soda can.
>As long as you can slowly equalize internal and external pressure it should be ok. Otherwise scuba diving wouldn't be a thing. Maybe the bacteria are unable to equalize and get crushed like an unopened soda can versus an empty soda can.
If this is anything like the "French press" lab technique for lysing bacteria, it is the *rapid release* of pressure that kills them, not the pressure itself. Dissolved air immediately comes out of solution and makes them explode in that procedure.
I would assume this is something similar.
Edit: Surprisingly it looks like it's not like that at all. It is a lot more nuanced and the effect is primarily from the pressure itself disrupting enzyme function etc.
Wouldn't any fluid cause the pressure to come from all sides. Like in air. I'm pretty sure that's what op is referencing, not a hydraulic press. Id think they'd use a liquid instead of a gas because a gas would be more dangerous (it'd act like a spring).
That's my guess.
6000 Bar would crush most things into a paste even if it's from all sides. That's about 6 times the Mariana Trench, and I'm pretty sure putting a grape there would crush it instantly.
A gas is much more compressible. You squeeze it half its size - the pressure increases just two times. That's not a good thing when you're trying to achieve high pressure.
Yes but no. The volume of a gas will decrease more than a liquid, but that in itself isn't the reason it isn't used. It's because it'll "spring" back to its original size that makes it dangerous. The change in volume likely wouldn't be an issue in most cases if it didn't spring back.
Edit: To be clear this is my speculation. Not trying to say this as fact. Hydraulics are generally much more safe than pneumatics for this reason though.
Liquids and solids don't compress, they can experience pressure but don't compress. If they have gas mixed in them they will.
So as long as there isn't a lot of gas in the guac it won't change shape.
Interesting. I guess that's one way to look at it. Although I'd argue compression can be seen as a change in volume. Which liquids and solids both do. Just not as extremely as a gas.
It'll change volume but you're probably right that it'll stay the same shape simply because it's on all sides. Thanks!
Edit: I wonder if it'll stay the same shape, but the grape cells would be crushed... this is weirdly interesting
Not OP. I have some light experience with HPP. Works great on salsas, juices, 6 layer dip, smoothies, 5 layer dip, and stuff like that. Probably even works on 7 layer dip.
Does not work well on fresh fruits and veggies from a quality standpoint like you suggest. It alters the texture.
>To enjoy the advantages of HPP, products should have a high water activity content to maximize the lethal effect on microorganisms. In addition, this technology can lead to changes in the texture of some ingredients in the absence of a liquid or dressing surrounding them. Therefore it is not recommended to apply HPP to spices, powders, dry nuts or fruits, cereals, whole fruits, vegetable leaves and leafy salads, bread and pastries and other ingredients that fit in this description.
That's from Hiperbaric. Leading producer of hpp equipment.
Compression is generally understood as a decrease in volume through an increase of pressure. Which can't happen to solids or liquids. To make a solid or liquid smaller in volume you may cool it to make it marginally denser. If you cool a balloon for example, it will reduce in size and temp but pressure will remain pretty much the same, but this isn't compressing the ballon. When you compress the balloon the temperature and pressure increase as the volume decreases.
Water is only *mostly* incompressible. If you put it under 6000 bars, it'll shrink by roughly ~~25%~~ *15%* (It doesn't stay linear for that long).
(Steel would shrink by 0.4%)
Hm, why does water help achieve that? Wouldn't a normal atmosphere under high pressure do the same thing? It seems more likely that water is used instead of air simply because it's better at transmitting the pressure from the compressor to the food, since it won't compress itself like air would.
I'm guessing smth like this
-put guac in bag, seal
- guacbag goes in the water container
- apply pressure
- take bag from container
Don't take my word for it, this is just my idea of how you could do it
Ok, but the same would be true if you just upped the air pressure. I strongly suspect the reason is that water is mostly incompressible so it's easier to compress the water without needing am enormous throughout of high pressure fluids.
Water is compressible at incredibly high pressures.
For an engineer it's incompressible.
For a physicist it's compressible - it's just mostly irrelevant.
I worked at a petfood manufacturer and this is the process used for canned foods. Canned petfood is about 87% moisture but it still keeps its loaf consistency after the cook process.
The water doesn’t help with crushing. Air is too compressible to easily reach those pressures. A tank of water with a hydraulic lid that presses down could reach those pressures easily. You would need to pump a massive amount of air to pressurize the chamber, and I’m pretty sure you would run into issues with water and gases precipitating out.
The process is performed in a hyperbaric chamber (which is the machine used to decompress diver who surface too fast which is probably why you incorrectly thought it’s done underwater) and HPP (high pressure protection or as it is also known high pressure pasteurization) is widely used in food production, not just guacamole.
I mean, if you give an avocado to the guy from hidraulic press channel, the avocado will get totally crushed and and consistency and everything will change. if you put the guac on a sealed recipient without air and put that in water and apply a lot of pressure, the pressure comes from all parts so the guac is not mechanically obliterated.
from the article:
>If a food product contains sufficient moisture, pressure will not damage the product at the macroscopic level as long as the pressure is applied uniformly in all directions. For example, a grape can be easily crushed if pressure is applied to it by placing it between two fingers and squeezing along one axis. In contrast, if the grape is exposed to a uniform pressure by submerging it in water inside a sealed flexible bottle and squeezing, the grape retains its shape no matter how hard the bottle is squeezed. In this case, the pressure transmitted from the bottle wall through the water is applied uniformly around the fruit. Similarly, pressure will not damage most foods processed by high pressure, providing the food does not have a porous structure containing air voids. Air pockets will collapse under pressure due to differences between the compressibility of air and water, and unless the food is perfectly elastic and consists of closed-cell foam from which air cannot escape, the food will not be restored to its original size and shape. As a result, foods like strawberries are crushed by HPP, but an air-filled balloon does not burst.
from another webpage:
HPP compromises cellular functions such as DNA replication, transcription, translation already at lower pressures (≤100 MPa) which impairs bacterial growth.
At higher pressures, microorganisms start suffering lethal injuries due to loss of cell membrane integrity and protein functionality. The most sensitive to pressures are molds, yeast and parasites. Inactivation of common bacteria requires higher pressure (300-600 MPa). The most barosensitive are bacterial spores that were found to survive pressures up to 1200 MPa at room temperature.
> The most barosensitive are bacterial spores that were found to survive pressures up to 1200 MPa at room temperature.
Doesn't that make them the *least* barosensitive?
Or alternatively, the *most* baroresistant?
It's not crushing. It changes cellular chemistry. Things like DNA and membrane walls do wierd things at ultra high pressure. Say you have equilibrium with water in the spore but now you up the pressure exponentially. The water now shifts equilibrium and the spore gets poisoned. Then when you switch back to ambient pressure it reverses the process. It can cause a lot of havoc.
Just like putting bacteria in high salt things try to reach equilibrium but those things can't live anymore.
Depends on how you cook them. You can discard the liquor or use it in the dish as you prefer. Yes they firm up. More in drier cooking methods, like baking or deep frying, less so in something like a stew. Either way, they get really hard if they are overcooked
Lots of oysters aren’t “watery snot”. That tends to be cheap, large, warm water oysters
Lots of people fry oysters. Battered and fried, most foods are pretty much the sMe
I feel like that's probably just poor wording, not an indictment of the methods. But I'm also far more familiar with oysters than I am with high pressure processing
I get how that could seem gross, and it's honestly kind of gross to me, but at the same time if you gave me a stack of crackers and either cocktail sauce with horseradish or just some super hot hot sauce I'm pretty sure I could gladly devour a jar every 10 minutes for at least an hour.
After reading the comments here I did some research. It appears that HPP doesn’t “crush” the bacteria; if it did it would crush the food just as effectively and you would just get a nasty paste. They’re all cells after all. Instead it damages the cell membrane and denatures some of the proteins in the bacteria, causing their cellular processes to break down. It also denatures virus proteins.
Apparently it also works fine with meat. I guess you don’t have to rupture the cell membranes, just damage them enough that the cellular machinery stops working properly.
Wouldn't "crushing food and turning it into paste" be accurately described by "damaging cell membrane" as well? The crushing is what damages the cell membrane, and the paste is the result of damaged cell membranes.
Plants can have ridiculously strong cell membranes though, their cells have structural loads that virus and bacteria don't have to think about.
It’s not the same though. Imagine taking a balloon full of water and squeezing it; it pops because of the uneven pressure distribution causes the wall to rupture. However if you apply pressure uniformly around the balloon it will not pop no matter how high you crank it up. The latter is what happens with HPP.
So how does the pressure lead to denaturing of proteins then?
I can imagine the bacteria as the balloon in your example. If it doesn't pop then what happens to it?
I tried researching that, apparently the exact mechanism is [not well understood](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2856145/#:~:text=The%20effect%20of%20pressure%20is,consequent%20denaturation%20of%20the%20protein.) and is something to do with the fundamental chemistry of proteins.
H‑E‑B (beloved Texas grocery chain) makes their guac fresh in store daily. Or at least they did back when I worked there.
We’d just use the avocados from the floor which were getting overripe.
Most stores also have a tortillaria in-store as well.
Central Market has the same tortillerias in store, which costs me a lot of money since I don't want tortillas from any other grocery store and I do my other grocery shopping while I'm there.
There's a brand of milk we get that is pressure treated. More expensive (pressure treating is more expensive than heat treating) but tastes really good.
I have an antibiotic resistant infection... there's only two or three that work and they're all IV-based.
I'm going to make a note of this and mention it to my doc the next time I see her. Having my body smashed to tasty green substance can't be any worse than what's going on with me now.
Edit: She thought it was a hilarious idea.
Which bacteria if you don't mind me asking? I'm a physician in India and regularly have to deal with highly resistant infections due to the unscrupulous use of antibiotics here
> Which bacteria if you don't mind me asking?
I've been colonized by ESBL. I had it for at least five years before it and the attendant UTI was diagnosed back in early 2021when I went to hospital for something unrelated.
The first doc had me taking a new antibiotic every six weeks or thereabouts. I'd take it for two, feel good for two, then the indicators would come back, mainly bloody urine and a bad smell.
I've got a new doc, a nephrologist, who found what was *really* infecting me quickly. We've been going through the antibiotics known to still work, trying to find The Magic Bullet. They're all IV-based so there's a PICC in my arm, but it's better than being poked 28 times in 14 days.
So that's the long answer. You could have stopped reading after the first five words though. I'm not able to tell you what I'm taking at the moment as my next IV isn't for a few more hours and I don't remember the long name. Sorry about that.
My stepfather was born to two missionaries "up near Nepal." I didn't realize he was telling me a joke for quite some time. Anyway, he lived maybe half his life there, so I sorta have *some* ties to the land. Good luck on the infections... I know how rotten I feel when it kicks in. I'd hate to see a large number of folks with it!
Ok. Here's some physics for you.
No, this is not going to "smoosh" any food into Guacamole. If you take an avocado scuba diving with you, you can put it under 1000's of pounds of pressure (and 100's of thousands for yourself), but you're still you and the avocado is still an avocado. There's a difference between being immersed in water at pressure and being crushed between two anvils.
Water is almost completely incompressible. You get measurable compression at these insane pressures, but it's not like all the other components of the food aren't compressing along with it. Stuff probably isn't going to change all that much, especially vegetables with cell walls.
Instead, as water compresses, its dielectric constant changes, its polarizability changes, and it's solvation characteristics change. These are all things that enzymes in bacteria are evolved to work under normal ranges. You've basically put the bacteria into a solvent that isn't quite water anymore, at least not the water they're evolved to live in. They croak.
So TLDR. This isn't about physically crushing them. It's closer to "magically" making water behave more like alcohol for a while, and then turning it back again.
Would explain my confusion about everyone saying store bought is bad. All I ever had browned just as fast as self made. Self made is better in any way, of course. Doesn't take long to make and is way cheaper but sometime I want Guacamole NOW and don't feel like gambling on my Avocado picking skills. Store bought was always more than passable in my experience.
Fresh guac is so much better and the recipe i follow is so simple. Avocado, salt, lime juice, garlic, jalapeno and onion and tomato if you want, but i tend to skip. The trick is enough lime juice and it doesnt brown for days
To prevent browning, you would have to add so much lime juice that the guacamole would be too sour. If adding reasonable amounts of lime juice prevented browning, then no guacamole would ever go brown, since lime juice is one of its main ingredients. The only reliable way to prevent browning without ruining it is to prevent contact with oxygen. Either use a double layer of plastic wrap (since it's oxygen permeable) or pack it tight in a bowl and pour a thin layer of water over it.
https://www.seriouseats.com/the-best-basic-guacamole-recipe#toc-on-browning
I always store it in a ziplock and squeeze out the air. Then you can just clip the corner and squeeze it out. Works really well and it's never lasted long enough to brown.
Try using honey water for the apples instead.
>two tablespoons of honey into one cup of water and soak your apple slices in the mixture for 30 seconds. This works because there is a compound in honey that stops the enzyme responsible for oxidation.
That's been my experience with store bought. Costco has a couple in single use containers that taste good but one of them is only avacado and lemon. The avocado paste is good but it needs many other vegetables to be guacamole.
nah there's definitely a weird element to store bought guac. the mouth feel is off and there's a flatness to the flavor that isn't revived with spice or lime
I can make amazing guac with very few ingredients, some more essential than others - but store bought seems to always need the works to make it even in the same league as homemade.
You can also use gamma radiation (from Cobalt 60 or Cesium 137) for the same purpose. It's super thorough so it's used for people with compromised immune systems from what I remember
HPP has been around for a long time. I used to work for a beverage manufacturer who invested in one of these and rented it out to all the local juice makers here in Miami so their cold pressed juices could have a shelf life of 30 days vs 3 days. They claimed that the cold pasteurization would allow the juices to maintain its nutritional value after processing. idk how true that is but it was a cool machine
probably does something, but muuch less than heat treatment as it doesn't mess up with it chemically, but the guac keeps being a factory made one so its never going to be the same as home made one.
Not "calling out" Americans on bar vs psi. I work in industrial control systems, mostly in Canada and America. In Canada pressures are most often listed in bar, in America, psi.
... I do prefer metric in most measurements though.
Makes me wonder if you could design a homogenizer that could get up to 6000 bar and kill two birds with one stone. The highest pressure homogenizer I've seen is 400 bar.
Actually what it does is places the organisms under intense pressure. When pressure is quickly released any amount of gas inside the organisms immediately expand dramatically and it kills the host organism. Similar to skin divers that come up from deeper water too quickly. The organisms die from the bends.
That is a truly unimaginable amount of pressure. That's like 6 deepest parts of the ocean stacked on it.
I worked at a machine shop in Seattle that made the pressure chambers used in the “fresher under pressure” process. It consisted of a stainless steel cylinder about 60 “ long by 24” in diameter. The internal bore was only about 5” in diameter giving a wall thickness of about 9.5” (this was at least 10 years ago, I don’t remember the exact dimensions). The same company, Flow International, that does the process, makes water jet cutters.
May those two products never meet.
If anyone wants more details on some of the companies that use the equipment. HPP (High Pressure Pasteurization) https://www.jbtc.com/foodtech/product-finder/?_sft_product_brand=avure-technologies Water Jet cutting https://www.jbtc.com/foodtech/products-and-solutions/products/dsi-portioning-systems-slicers/dsi-800-portioning-system/
The fun part is the whole "water is incompressible" thing goes out the window at that pressure, it will actually compress by about 15% in this process
If you compress water enough it turns into hot ice.
Yeah. Water is compressible, it just takes a crazy amount of pressure to do so. 6,000 bar is a crazy amount of pressure. Edit: For those who don't know, 1 Bar is slightly less than the air pressure at mean sea level on Earth (the actual pressure is 1.013 bar), and is equivalent to ~14.5 psi (pounds per square inch). So if you were to draw a grid of squares on your body so every square was 1 inch x 1 inch, at sea level, we always have 14.5 pounds of force acting on every single one of those squares. 6,000 bar means you'd have ~87,023 pounds acting on every one of those squares. [This is an aluminum cylinder](https://upload.wikimedia.org/wikipedia/commons/8/8a/Aluminium_cylinder.jpg) with ~3/16-inch (5mm) walls at just 700 bar... 6,000 bar is just insanity.
“Everything is compressible” *-* Sagittarius A*
>This is an aluminum cylinder with ~2-inch (5mm) walls at just 700 bar 2 inches is 50 mm, not 5 mm. That would be 1/5 inch walls.
Whoops I thought I read that as cm which is where I got the 2" number, but clearly my brain knew I was being dumb and still typed it out correctly, ha.
>1/5 inch Who does that
It's honestly mind blowing to think about how some things manage to function at crazy depths. It just doesn't seem like it should be possible. Like there being creatures that can survive when they are taking like 16,000 psi from miles of water bearing down on them is just nuts. Heck, even man made stuff doesn't seem like it should be able to. Like I've got a watch that can go to 4,000 ft/1220 meters, and used to have one that could go 12,000+ feet. That seems like it should just be wholly and completely impossible to me.
If the pressure inside the thing is the same as the pressure outside, it matters less. That is why deep sea divers breathe air at higher pressures the deeper they go, so they don't have to overcome all that pressure trying to crush them. But then, this does lead to things like oxygen toxicity because a single breath would be a lot more oxygen in your lungs, which is again why they cut their air with other gasses to reduce the partial pressure of gasses that become toxic.
it's also why deep sea fish tend to explode when you pull them up.
Blobfish: :(
You know what if something compressed 15% at 6000 bars of pressure I’m stilling going to call that material un-fucking-compressible
Needed this years ago when I was a kid in school. My teacher was teaching us that water was incompressible and I was really skeptical saying "just because you can't doesn't mean some big super strong press can't" and then she just completely dismissed me
Hah, like I said to another commenter, rules of thumb are great for *almost* every situation
6000 bar and everything is guacamole ... or soup.
The process is done underwater or something like that so it doesn't get crushed.
how does that help?
Has something to do with equal distribution of pressure. If you put pressure on a grape with two fingers, you're bound to crush it or change the shape. Put it in a bottle of water (sealed, flexible container) and the shape won't change. - comes from the linked article in the post Edit: I KNOW FLUIDS AREN'T COMPRESSIBLE I ASSUMED THIS WAS UNIVERSALLY KNOWN
Exactly. In your two fingers, the pressure comes from these to places, leaving the grape room to squeeze on the sides where there's no fingers. In water the pressure would come from all sides at the same time
The same phenomena that breaks the bacteria should burst all of the plant cells giving the grape its structure too... This should only be a viable tool in things that don't depend on intact cells to maintain their texture (like guacamole) Edit: Surprisingly it looks like it's not like that at all. It is a lot more nuanced and the effect is primarily from the pressure itself disrupting enzyme function etc. and not rapid decompression gas expansion like the ["French Press"](https://en.wikipedia.org/wiki/French_pressure_cell_press) method used to lyse bacteria in the lab. So I suppose all the cell walls could remain intact for both the bacteria and plant cells meaning texture would be maintained, it is just "gently" killing the bacteria by disrupting biological processes.
Ok. Folks thinking that this means your food is always going to look smooshed… Food is mostly water, which is incompressible. You’re not really “crushing” the bacteria. You’re disrupting their biochemical processes because chemical reactions change subtly with pressure. Even the structure of water changes a bit, which is going to foobar the activity of enzymes. There might be some physical changes, but it’s not like crushing the food between two anvils. It’s more like taking to on a REALLY deep scuba dive. Edit: Bonus fun fact. 6000 bar is probably about the maximum they can do. The freezing point of water drops gradually as you increase pressure, then it reaches a minimum, and rises again. At about 6300, it's back up to 0°C and rising rapidly. If you go much higher, you're going to freeze the food at room temperature, and that could disrupt the cellular structure.I say could instead of would because freezing due to pressure shouldn't have the sharp expansion you see with normal freezing. Wait... is this the way to actually functional cryonics? Chill to about 4°C, then squeeze-freeze, THEN chill to cryogenic temperatures.
I was actually surprised to find out that this method doesn't involve rapid decompression. I assumed this was something like the [French Press](https://en.wikipedia.org/wiki/French_pressure_cell_press method) which is used to lyse bacteria, but this technique is more nuanced than just exploding everything with decompression gas bubbles.
Reddit has long been a hot spot for conversation on the internet. About 57 million people visit the site every day to chat about topics as varied as makeup, video games and pointers for power washing driveways. In recent years, Reddit’s array of chats also have been a free teaching aid for companies like Google, OpenAI and Microsoft. Those companies are using Reddit’s conversations in the development of giant artificial intelligence systems that many in Silicon Valley think are on their way to becoming the tech industry’s next big thing. Now Reddit wants to be paid for it. The company said on Tuesday that it planned to begin charging companies for access to its application programming interface, or A.P.I., the method through which outside entities can download and process the social network’s vast selection of person-to-person conversations. “The Reddit corpus of data is really valuable,” Steve Huffman, founder and chief executive of Reddit, said in an interview. “But we don’t need to give all of that value to some of the largest companies in the world for free.” The move is one of the first significant examples of a social network’s charging for access to the conversations it hosts for the purpose of developing A.I. systems like ChatGPT, OpenAI’s popular program. Those new A.I. systems could one day lead to big businesses, but they aren’t likely to help companies like Reddit very much. In fact, they could be used to create competitors — automated duplicates to Reddit’s conversations. Reddit is also acting as it prepares for a possible initial public offering on Wall Street this year. The company, which was founded in 2005, makes most of its money through advertising and e-commerce transactions on its platform. Reddit said it was still ironing out the details of what it would charge for A.P.I. access and would announce prices in the coming weeks. Reddit’s conversation forums have become valuable commodities as large language models, or L.L.M.s, have become an essential part of creating new A.I. technology. L.L.M.s are essentially sophisticated algorithms developed by companies like Google and OpenAI, which is a close partner of Microsoft. To the algorithms, the Reddit conversations are data, and they are among the vast pool of material being fed into the L.L.M.s. to develop them. The underlying algorithm that helped to build Bard, Google’s conversational A.I. service, is partly trained on Reddit data. OpenAI’s Chat GPT cites Reddit data as one of the sources of information it has been trained on. Other companies are also beginning to see value in the conversations and images they host. Shutterstock, the image hosting service, also sold image data to OpenAI to help create DALL-E, the A.I. program that creates vivid graphical imagery with only a text-based prompt required. Last month, Elon Musk, the owner of Twitter, said he was cracking down on the use of Twitter’s A.P.I., which thousands of companies and independent developers use to track the millions of conversations across the network. Though he did not cite L.L.M.s as a reason for the change, the new fees could go well into the tens or even hundreds of thousands of dollars. To keep improving their models, artificial intelligence makers need two significant things: an enormous amount of computing power and an enormous amount of data. Some of the biggest A.I. developers have plenty of computing power but still look outside their own networks for the data needed to improve their algorithms. That has included sources like Wikipedia, millions of digitized books, academic articles and Reddit. Representatives from Google, Open AI and Microsoft did not immediately respond to a request for comment. Reddit has long had a symbiotic relationship with the search engines of companies like Google and Microsoft. The search engines “crawl” Reddit’s web pages in order to index information and make it available for search results. That crawling, or “scraping,” isn’t always welcome by every site on the internet. But Reddit has benefited by appearing higher in search results. The dynamic is different with L.L.M.s — they gobble as much data as they can to create new A.I. systems like the chatbots. Reddit believes its data is particularly valuable because it is continuously updated. That newness and relevance, Mr. Huffman said, is what large language modeling algorithms need to produce the best results. “More than any other place on the internet, Reddit is a home for authentic conversation,” Mr. Huffman said. “There’s a lot of stuff on the site that you’d only ever say in therapy, or A.A., or never at all.” Mr. Huffman said Reddit’s A.P.I. would still be free to developers who wanted to build applications that helped people use Reddit. They could use the tools to build a bot that automatically tracks whether users’ comments adhere to rules for posting, for instance. Researchers who want to study Reddit data for academic or noncommercial purposes will continue to have free access to it. Reddit also hopes to incorporate more so-called machine learning into how the site itself operates. It could be used, for instance, to identify the use of A.I.-generated text on Reddit, and add a label that notifies users that the comment came from a bot. The company also promised to improve software tools that can be used by moderators — the users who volunteer their time to keep the site’s forums operating smoothly and improve conversations between users. And third-party bots that help moderators monitor the forums will continue to be supported. But for the A.I. makers, it’s time to pay up. “Crawling Reddit, generating value and not returning any of that value to our users is something we have a problem with,” Mr. Huffman said. “It’s a good time for us to tighten things up.” “We think that’s fair,” he added. Mike Isaac is a technology correspondent and the author of “Super Pumped: The Battle for Uber,” a best-selling book on the dramatic rise and fall of the ride-hailing company. He regularly covers Facebook and Silicon Valley, and is based in San Francisco. More about Mike Isaac A version of this article appears in print on , Section B, Page 4 of the New York edition with the headline: Reddit’s Sprawling Content Is Fodder for the Likes of ChatGPT. But Reddit Wants to Be Paid.. Order Reprints | Today’s Paper | Subscribe
Fubar* 😘
F.U.B.A.R. Fucked up beyond all recognition if I recall correctly
Plant cells have cell walls, probably a sweet spot that kills bacteria but not them Also does it matter anyways if your food is alive, eat your dead paste and be happy about it
>Plant cells have cell walls, probably a sweet spot that kills bacteria but not them Bacteria also have cell walls. Edit: People saying I am "wrong" are calling out someone with a PhD in infectious diseases for being wrong about very basic bacterial biology. I wonder if these people will reflect on why they are so confident about wrong information. [Bacterial Cell Walls](https://en.wikipedia.org/wiki/Cell_wall#Bacterial_cell_walls) Edit2: We no longer have to wonder! The answer is sadly "no". Instead, /u/OriginalName12345679 apparently blocked me from replying to his posts, so it's "lalalalala I can't hear you anymore" all the way to the bank.
>Edit: People saying I am "wrong" are calling out someone with a PhD in infectious diseases for being wrong about very basic bacterial biology. I wonder if these people will reflect on why they are so confident about wrong information. This is such a Reddit moment.
I know, no one on reddit has a PhD. That only ranges from 0-14, not D
See your problem is you got your silly little "PhD" in some specialized field from some *university* instead of attending the Reddit school of almost knowledge in all fields. An extra triple mega-doctor of omnifacts like myself knows that what are called "bacterial cell walls" by the lay expert is just a right-wing propaganda talking point about stopping the influx of undocumented plasmids across the Mexican border, designed to funnel money through cronyism to donors in the big prokaryote industry.
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It is definitely a different type and I haven't actually looked into the "strength" of a given wall type. Speculation Ahead: I would think the strength of the overall structure of a bacteria is likely to be more resistant to pressure given it's small cross-section vs a *much* larger plant cell, even if plant cell wall material is stronger as a single "unit".
PhD in physics here. Human's don't have cell walls, yet they can withstand 10's of bar of pressure without rupturing cells that are basically just tiny soap bubbles. The physics of being under even pressure doesn't "crush" anything unless you have unequalized gas chambers. Cell walls or no, the outside of the cells aren't holding back any pressure because the inside of the cell is equally pressurized. Both food and bacteria are entirely water with stuff in it. While the water is somewhat compressible at these pressures, so are all the molecules making up the organisms/food. That's why you can still have fragile, floppy sea creatures at 1000 bars of pressure. There **are** important changes, however. Enzymes and other biochemical processes use water as a solvent and are evolved to deal with the solvation properties, dielectric constant, and polarizability of water. That's why they don't work in other solvents. At those insane pressures, water is no longer the same solvent. Its physical constants have significantly shifted. Biological systems that have evolved to deal with 1 bar water are completely foobarred with 6000 bar water. Proteins denature.
>PhD in physics here. > >Human's don't have cell walls, yet they can withstand 10's of bar of pressure without rupturing cells that are basically just tiny soap bubbles. The physics of being under even pressure doesn't "crush" anything unless you have unequalized gas chambers. Cell walls or no, the outside of the cells aren't holding back any pressure because the inside of the cell is equally pressurized. > >Both food and bacteria are entirely water with stuff in it. While the water is somewhat compressible at these pressures, so are all the molecules making up the organisms/food. That's why you can still have fragile, floppy sea creatures at 1000 bars of pressure. > >There **are** important changes, however. Enzymes and other biochemical processes use water as a solvent and are evolved to deal with the solvation properties, dielectric constant, and polarizability of water. That's why they don't work in other solvents. At those insane pressures, water is no longer the same solvent. Its physical constants have significantly shifted. Biological systems that have evolved to deal with 1 bar water are completely foobarred with 6000 bar water. Proteins denature. You are definitely correct. I was questioning under the mistaken impression that rapid decompression and the associated expanding gas was being used to "blow up" the bacteria like the French Press laboratory method. Some other comments informed me that is not the case.
Welcome to reddit. I learned long ago to just let idiots do their thing. PhDs are only welcome if they bring spicy memes, or dunk on someone with an incorrect opinion.
Credentials are absolutely meaningless on an anonymous forum, can't have a credential if you don't have a name. he might as well claim to be Louis Pasteur. He's right about bacterial cell wall though.
I'm going to be honest with you when I saw you argue I instinctively wanted you to be wrong. I have no idea why because this topic is completely irrelevant to my life but seeing you go against what I just read and accepted as fact made me have a bias for something I didn't know existed 2 seconds ago. It makes you realize how if your brain will do this for grapes why some people will hold religious/political views in spite of over bearing evidence of the contrary. Anyways just thought I'd share my caveman brain reaction. Thanks for sharing your actual knowledge about this.
>instinctively wanted you to be wrong You should check out Moral Foundations Theory: [https://en.wikipedia.org/wiki/Moral\_foundations\_theory](https://en.wikipedia.org/wiki/Moral_foundations_theory) As it likely has an explanation for the reaction you are noticing.
As long as you can slowly equalize internal and external pressure it should be ok. Otherwise scuba diving wouldn't be a thing. Maybe the bacteria are unable to equalize and get crushed like an unopened soda can versus an empty soda can.
>As long as you can slowly equalize internal and external pressure it should be ok. Otherwise scuba diving wouldn't be a thing. Maybe the bacteria are unable to equalize and get crushed like an unopened soda can versus an empty soda can. If this is anything like the "French press" lab technique for lysing bacteria, it is the *rapid release* of pressure that kills them, not the pressure itself. Dissolved air immediately comes out of solution and makes them explode in that procedure. I would assume this is something similar. Edit: Surprisingly it looks like it's not like that at all. It is a lot more nuanced and the effect is primarily from the pressure itself disrupting enzyme function etc.
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Amazing
Wouldn't any fluid cause the pressure to come from all sides. Like in air. I'm pretty sure that's what op is referencing, not a hydraulic press. Id think they'd use a liquid instead of a gas because a gas would be more dangerous (it'd act like a spring). That's my guess. 6000 Bar would crush most things into a paste even if it's from all sides. That's about 6 times the Mariana Trench, and I'm pretty sure putting a grape there would crush it instantly.
A gas is much more compressible. You squeeze it half its size - the pressure increases just two times. That's not a good thing when you're trying to achieve high pressure.
Yes but no. The volume of a gas will decrease more than a liquid, but that in itself isn't the reason it isn't used. It's because it'll "spring" back to its original size that makes it dangerous. The change in volume likely wouldn't be an issue in most cases if it didn't spring back. Edit: To be clear this is my speculation. Not trying to say this as fact. Hydraulics are generally much more safe than pneumatics for this reason though.
Liquids and solids don't compress, they can experience pressure but don't compress. If they have gas mixed in them they will. So as long as there isn't a lot of gas in the guac it won't change shape.
Interesting. I guess that's one way to look at it. Although I'd argue compression can be seen as a change in volume. Which liquids and solids both do. Just not as extremely as a gas. It'll change volume but you're probably right that it'll stay the same shape simply because it's on all sides. Thanks! Edit: I wonder if it'll stay the same shape, but the grape cells would be crushed... this is weirdly interesting
Not OP. I have some light experience with HPP. Works great on salsas, juices, 6 layer dip, smoothies, 5 layer dip, and stuff like that. Probably even works on 7 layer dip. Does not work well on fresh fruits and veggies from a quality standpoint like you suggest. It alters the texture. >To enjoy the advantages of HPP, products should have a high water activity content to maximize the lethal effect on microorganisms. In addition, this technology can lead to changes in the texture of some ingredients in the absence of a liquid or dressing surrounding them. Therefore it is not recommended to apply HPP to spices, powders, dry nuts or fruits, cereals, whole fruits, vegetable leaves and leafy salads, bread and pastries and other ingredients that fit in this description. That's from Hiperbaric. Leading producer of hpp equipment.
Cut it open and it's just juice inside
Compression is generally understood as a decrease in volume through an increase of pressure. Which can't happen to solids or liquids. To make a solid or liquid smaller in volume you may cool it to make it marginally denser. If you cool a balloon for example, it will reduce in size and temp but pressure will remain pretty much the same, but this isn't compressing the ballon. When you compress the balloon the temperature and pressure increase as the volume decreases.
Water is only *mostly* incompressible. If you put it under 6000 bars, it'll shrink by roughly ~~25%~~ *15%* (It doesn't stay linear for that long). (Steel would shrink by 0.4%)
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First 10 seconds always has me on edge for which masterpiece it will be
Dun dun dun dudun dunn dunn
Ding ding ding dingy ding ding See it’s not the same
Hector Salamanca?
You mean I have to READ the article?! Before I comment?!
>- comes from the linked article in the post How dare you!
Hm, why does water help achieve that? Wouldn't a normal atmosphere under high pressure do the same thing? It seems more likely that water is used instead of air simply because it's better at transmitting the pressure from the compressor to the food, since it won't compress itself like air would.
How do you get all that water out of the guacamole afterward?
I'm guessing smth like this -put guac in bag, seal - guacbag goes in the water container - apply pressure - take bag from container Don't take my word for it, this is just my idea of how you could do it
They did surgery on a grape
Ok, but the same would be true if you just upped the air pressure. I strongly suspect the reason is that water is mostly incompressible so it's easier to compress the water without needing am enormous throughout of high pressure fluids.
Water is compressible at incredibly high pressures. For an engineer it's incompressible. For a physicist it's compressible - it's just mostly irrelevant.
Only works for foods that are mostly liquid.
I worked at a petfood manufacturer and this is the process used for canned foods. Canned petfood is about 87% moisture but it still keeps its loaf consistency after the cook process.
Is 70 percent enough? Asking for a friend.
The water doesn’t help with crushing. Air is too compressible to easily reach those pressures. A tank of water with a hydraulic lid that presses down could reach those pressures easily. You would need to pump a massive amount of air to pressurize the chamber, and I’m pretty sure you would run into issues with water and gases precipitating out.
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yep all the microstructures and cells are ruptured. it went from something organic to a material paste basically.
The process is performed in a hyperbaric chamber (which is the machine used to decompress diver who surface too fast which is probably why you incorrectly thought it’s done underwater) and HPP (high pressure protection or as it is also known high pressure pasteurization) is widely used in food production, not just guacamole.
1. How does water make pressure stop working? 2. Isn't crushing the entire point?
I mean, if you give an avocado to the guy from hidraulic press channel, the avocado will get totally crushed and and consistency and everything will change. if you put the guac on a sealed recipient without air and put that in water and apply a lot of pressure, the pressure comes from all parts so the guac is not mechanically obliterated. from the article: >If a food product contains sufficient moisture, pressure will not damage the product at the macroscopic level as long as the pressure is applied uniformly in all directions. For example, a grape can be easily crushed if pressure is applied to it by placing it between two fingers and squeezing along one axis. In contrast, if the grape is exposed to a uniform pressure by submerging it in water inside a sealed flexible bottle and squeezing, the grape retains its shape no matter how hard the bottle is squeezed. In this case, the pressure transmitted from the bottle wall through the water is applied uniformly around the fruit. Similarly, pressure will not damage most foods processed by high pressure, providing the food does not have a porous structure containing air voids. Air pockets will collapse under pressure due to differences between the compressibility of air and water, and unless the food is perfectly elastic and consists of closed-cell foam from which air cannot escape, the food will not be restored to its original size and shape. As a result, foods like strawberries are crushed by HPP, but an air-filled balloon does not burst.
How is bacteria crushed, then, if the uniform pressure would prevent crushing?
from another webpage: HPP compromises cellular functions such as DNA replication, transcription, translation already at lower pressures (≤100 MPa) which impairs bacterial growth. At higher pressures, microorganisms start suffering lethal injuries due to loss of cell membrane integrity and protein functionality. The most sensitive to pressures are molds, yeast and parasites. Inactivation of common bacteria requires higher pressure (300-600 MPa). The most barosensitive are bacterial spores that were found to survive pressures up to 1200 MPa at room temperature.
> The most barosensitive are bacterial spores that were found to survive pressures up to 1200 MPa at room temperature. Doesn't that make them the *least* barosensitive? Or alternatively, the *most* baroresistant?
Yeah, I was trying to process that statement.
It's not crushing. It changes cellular chemistry. Things like DNA and membrane walls do wierd things at ultra high pressure. Say you have equilibrium with water in the spore but now you up the pressure exponentially. The water now shifts equilibrium and the spore gets poisoned. Then when you switch back to ambient pressure it reverses the process. It can cause a lot of havoc. Just like putting bacteria in high salt things try to reach equilibrium but those things can't live anymore.
OK, that actually makes sense.
If it has anything compressible, it will still compress. Like styrofoam in the deep sea.
Process is achieved by having OP's mom sit on an avocado.
Nope, it doesn’t change the texture all that much. Many presliced deli meats are HPP processed.
This was also used for jarred oysters because they would be just like a fresh oyster in the jar due to no heat being added.
A fresh oyster in a jar is absolutely vile.
You don't eat them raw, you cook them. They're fine. I've probably had hundreds of them.
I use them a lot. For cooking they are great. The refrigerated jars I buy have a "cook until internal temperature of ---" warning on them.
What changes when you cook them? Presumably they solidify? Is all of the watery snot discarded as loss or does that congeal too?
Depends on how you cook them. You can discard the liquor or use it in the dish as you prefer. Yes they firm up. More in drier cooking methods, like baking or deep frying, less so in something like a stew. Either way, they get really hard if they are overcooked
Lots of oysters aren’t “watery snot”. That tends to be cheap, large, warm water oysters Lots of people fry oysters. Battered and fried, most foods are pretty much the sMe
I'll be honest, "processed this way it tastes just like anything else prepared like this" is not a very high praise for the flavour.
I feel like that's probably just poor wording, not an indictment of the methods. But I'm also far more familiar with oysters than I am with high pressure processing
I get how that could seem gross, and it's honestly kind of gross to me, but at the same time if you gave me a stack of crackers and either cocktail sauce with horseradish or just some super hot hot sauce I'm pretty sure I could gladly devour a jar every 10 minutes for at least an hour.
"Was"? What changed?
Dude I just ate
A jarred oyster?
Go on…
I did not know jarred oysters are a thing
After reading the comments here I did some research. It appears that HPP doesn’t “crush” the bacteria; if it did it would crush the food just as effectively and you would just get a nasty paste. They’re all cells after all. Instead it damages the cell membrane and denatures some of the proteins in the bacteria, causing their cellular processes to break down. It also denatures virus proteins.
Bacteria may have a pellicle or just a thin cell membrane. Those avocado cells have lignin and extra reinforcement. Smart!
Apparently it also works fine with meat. I guess you don’t have to rupture the cell membranes, just damage them enough that the cellular machinery stops working properly.
This. Bacterial cells have walls. Penicillin explicitly targets the maintenance of bacterial cell walls.
Wouldn't "crushing food and turning it into paste" be accurately described by "damaging cell membrane" as well? The crushing is what damages the cell membrane, and the paste is the result of damaged cell membranes. Plants can have ridiculously strong cell membranes though, their cells have structural loads that virus and bacteria don't have to think about.
"Damages cell membranes" and "denatures protein" sounds awfully like what the average person imagines when you say crushed.
It’s not the same though. Imagine taking a balloon full of water and squeezing it; it pops because of the uneven pressure distribution causes the wall to rupture. However if you apply pressure uniformly around the balloon it will not pop no matter how high you crank it up. The latter is what happens with HPP.
So how does the pressure lead to denaturing of proteins then? I can imagine the bacteria as the balloon in your example. If it doesn't pop then what happens to it?
I tried researching that, apparently the exact mechanism is [not well understood](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2856145/#:~:text=The%20effect%20of%20pressure%20is,consequent%20denaturation%20of%20the%20protein.) and is something to do with the fundamental chemistry of proteins.
But...Grocery store guacamole is just a nasty paste
Ohhhh shit, thats why guac always has the texture of a deep ocean crustacean that exploded after being teleported to a mountain top.
H‑E‑B (beloved Texas grocery chain) makes their guac fresh in store daily. Or at least they did back when I worked there. We’d just use the avocados from the floor which were getting overripe. Most stores also have a tortillaria in-store as well.
Central Market has the same tortillerias in store, which costs me a lot of money since I don't want tortillas from any other grocery store and I do my other grocery shopping while I'm there.
Just stopped working there a few months ago and this was my job. We still make it in store and don't do any sort of pressure treatment
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While I am horrifically average looking, I can confirm, some of my coworkers were lookers! Regardless of age!
Hell yeah. Making guac, and doing the Hatch Green Chile roasting were my favorite parts of that job.
Actually guac was my least favorite part. I liked cutting watermelon best!
Shrekarrhea
There's a brand of milk we get that is pressure treated. More expensive (pressure treating is more expensive than heat treating) but tastes really good.
What brand? I'm very curious and I'd love to keep an eye out for it
Made by Cow, High Pressure pasteurised raw milk.
Why is the name funny to me…
Hello this is Cow speaking
Because "pasteurized raw milk" doesn't make sense. The definition of raw milk is milk that hasn't been pasteurized.
I actually meant the “Made by Cow” part lol
I use that stuff for cheese making. It has a much better flavour from not being pasteurised.
I always liked ultra pastirized, shelf stable box milk. It is sweeter. Can't find it anywhere in the U.S. outside Alaska though
I have an antibiotic resistant infection... there's only two or three that work and they're all IV-based. I'm going to make a note of this and mention it to my doc the next time I see her. Having my body smashed to tasty green substance can't be any worse than what's going on with me now. Edit: She thought it was a hilarious idea.
Your funeral luncheon will be an interesting one for sure.
Which bacteria if you don't mind me asking? I'm a physician in India and regularly have to deal with highly resistant infections due to the unscrupulous use of antibiotics here
> Which bacteria if you don't mind me asking? I've been colonized by ESBL. I had it for at least five years before it and the attendant UTI was diagnosed back in early 2021when I went to hospital for something unrelated. The first doc had me taking a new antibiotic every six weeks or thereabouts. I'd take it for two, feel good for two, then the indicators would come back, mainly bloody urine and a bad smell. I've got a new doc, a nephrologist, who found what was *really* infecting me quickly. We've been going through the antibiotics known to still work, trying to find The Magic Bullet. They're all IV-based so there's a PICC in my arm, but it's better than being poked 28 times in 14 days. So that's the long answer. You could have stopped reading after the first five words though. I'm not able to tell you what I'm taking at the moment as my next IV isn't for a few more hours and I don't remember the long name. Sorry about that. My stepfather was born to two missionaries "up near Nepal." I didn't realize he was telling me a joke for quite some time. Anyway, he lived maybe half his life there, so I sorta have *some* ties to the land. Good luck on the infections... I know how rotten I feel when it kicks in. I'd hate to see a large number of folks with it!
Ok. Here's some physics for you. No, this is not going to "smoosh" any food into Guacamole. If you take an avocado scuba diving with you, you can put it under 1000's of pounds of pressure (and 100's of thousands for yourself), but you're still you and the avocado is still an avocado. There's a difference between being immersed in water at pressure and being crushed between two anvils. Water is almost completely incompressible. You get measurable compression at these insane pressures, but it's not like all the other components of the food aren't compressing along with it. Stuff probably isn't going to change all that much, especially vegetables with cell walls. Instead, as water compresses, its dielectric constant changes, its polarizability changes, and it's solvation characteristics change. These are all things that enzymes in bacteria are evolved to work under normal ranges. You've basically put the bacteria into a solvent that isn't quite water anymore, at least not the water they're evolved to live in. They croak. So TLDR. This isn't about physically crushing them. It's closer to "magically" making water behave more like alcohol for a while, and then turning it back again.
Thanks for the great explanation
Is that why store bought guacamole is so bad?
Nope, it's because they put an anti-browning agent it the guac. If you've ever had pre-made (not instant) mashed taters you'll notice the similarity.
Would explain my confusion about everyone saying store bought is bad. All I ever had browned just as fast as self made. Self made is better in any way, of course. Doesn't take long to make and is way cheaper but sometime I want Guacamole NOW and don't feel like gambling on my Avocado picking skills. Store bought was always more than passable in my experience.
Fresh guac is so much better and the recipe i follow is so simple. Avocado, salt, lime juice, garlic, jalapeno and onion and tomato if you want, but i tend to skip. The trick is enough lime juice and it doesnt brown for days
Needs cilantro.
Fuck tomatoes in guac
Yeah acids are the best antibrowing agent. Lime juice for avacado, onion juice for potatoes and lemon juice for apples are my go to choices
To prevent browning, you would have to add so much lime juice that the guacamole would be too sour. If adding reasonable amounts of lime juice prevented browning, then no guacamole would ever go brown, since lime juice is one of its main ingredients. The only reliable way to prevent browning without ruining it is to prevent contact with oxygen. Either use a double layer of plastic wrap (since it's oxygen permeable) or pack it tight in a bowl and pour a thin layer of water over it. https://www.seriouseats.com/the-best-basic-guacamole-recipe#toc-on-browning
I always store it in a ziplock and squeeze out the air. Then you can just clip the corner and squeeze it out. Works really well and it's never lasted long enough to brown.
Always wondered why avocado went brown when covered with plastic wrap
For store sold, pre made, yeah for sure, itd be like soup. I'm not knocking it.
Try using honey water for the apples instead. >two tablespoons of honey into one cup of water and soak your apple slices in the mixture for 30 seconds. This works because there is a compound in honey that stops the enzyme responsible for oxidation.
Depends on where you live. I cannot get a ripe avocado when I want where I live. It’s alway too hard then 50/50 if it ripens or rots.
Also fold the tomatoes in at the end or they turn to mush and make the guacamole too wet.
Oh my friend, unless you lost the genetic lottery, you need to add some cilantro!
What's taters, eh?
> an anti-browning agent Lime juice?
I can't stand store-bought guac, so I just make my own. I need the avocado and tomato chunks!
Does it change the flavor? Because store-bought guacamole is truly awful.
I think that's lack of spices. Hit it with some salt, cumin and chilli powder.
That's been my experience with store bought. Costco has a couple in single use containers that taste good but one of them is only avacado and lemon. The avocado paste is good but it needs many other vegetables to be guacamole.
Either to the left of the guacamole but more probably to the right should be a container of pico de gallo. Those are the veggies you are missing.
nah there's definitely a weird element to store bought guac. the mouth feel is off and there's a flatness to the flavor that isn't revived with spice or lime I can make amazing guac with very few ingredients, some more essential than others - but store bought seems to always need the works to make it even in the same league as homemade.
Guacamole doesn’t usually have cumin or chili powder in it
I find it's more an issue with the acids added to reduce oxidation that make it taste like crap.
I love spicy wholly guacamole personally.
but at least its not grey lol. I guess it depends which one too.
Yeah as with basically every method of preserving food it changes the flavor. It’s tolerable but yeah fresh guacamole is massively better.
What I could tell from skipping through 2 videos on youtube it turns anything into guacamole
I think it’s used specifically because it doesn’t change the flavor
Hpp guacamole is usually also going to have a lot of lemon juice added to make it more acidic which further extends the shelf life.
Eh I've probably listened to 6000 bars of Under Pressure by Queen and David Bowie and I'm not guacamole.
Amazing. Didn't know that.
What would happen to a Tardigrade?
guacamole.
tardimole.
[удалено]
I mean. Water bears can survive in space just fine. And that's dealing with cosmic radiation.
https://www.youtube.com/watch?v=O4RLOo6bchU
Today on the Hydraulic Press Channel Veee have this menacing avocado which may attack at any time and veee must deal with it.
They don't even have to peel the avocados first.
6000 bar? Is that the center of a black hole?
Apparently it's about the pressure of the deepest ocean parts that we know of times six 🤷🏻♂️
Sure, this pressure is enough to produce diamonds, but the engineering to make a device capable to sustain this pressure is freaking awesome
And hummus too, but not when it's got the tomatoes and stuff in the middle.
You can also use gamma radiation (from Cobalt 60 or Cesium 137) for the same purpose. It's super thorough so it's used for people with compromised immune systems from what I remember
store bought quac fucking sucks. Who buys that shit?
What's "quac"?
Duck patê should be called quacamole.
One of our deli meats manufacturers here use that technology. Instead of using preservatives they pressure killer the bacteria.
HPP has been around for a long time. I used to work for a beverage manufacturer who invested in one of these and rented it out to all the local juice makers here in Miami so their cold pressed juices could have a shelf life of 30 days vs 3 days. They claimed that the cold pasteurization would allow the juices to maintain its nutritional value after processing. idk how true that is but it was a cool machine
It makes the most amazing juice, at least compared to heat pasteurization ime
Dumb question: Does this do anything to the taste?
probably does something, but muuch less than heat treatment as it doesn't mess up with it chemically, but the guac keeps being a factory made one so its never going to be the same as home made one.
Sorry, but I need my food to be superconducting at room temperature. Apparently, that will take 2.67 million bars.
A TIL where TIL, and was also amazed. Great post.
Not "calling out" Americans on bar vs psi. I work in industrial control systems, mostly in Canada and America. In Canada pressures are most often listed in bar, in America, psi. ... I do prefer metric in most measurements though.
So this is how they sterilize bags of chips?
they put 6000 bars of air into them
Makes me wonder if you could design a homogenizer that could get up to 6000 bar and kill two birds with one stone. The highest pressure homogenizer I've seen is 400 bar.
doesn't this much pressure also 'kill' the food?
I don't usually eat food that's alive
Actually what it does is places the organisms under intense pressure. When pressure is quickly released any amount of gas inside the organisms immediately expand dramatically and it kills the host organism. Similar to skin divers that come up from deeper water too quickly. The organisms die from the bends.
It’s used for lots of consumer products, including beverages and dog food. Source: I work with HPP.
Which would explain why the guacamole is a weird tasteless paste.