Egg whites can be transformed into a material capable of filtering microplastics | Hacker News Reader

Egg whites can be transformed into a material capable of filtering microplastics

phys.org

156 pointswglb56 comments

Curiously egg whites are also used to remove particles from stock (chicken, veal, beef) when you want to have a crystal clear liquid.

Also used to filter wine - see https://www.winespectator.com/articles/are-egg-whites-really...

And Swedish egg coffee.

Which funnily is absolutely not a thing here in Sweden.

First time I heard about "Swedish egg coffee" from American colleagues I was really puzzled, had to do some research about it because I never heard or seen it. It seems to come from some Swedish immigrants to the USA that used eggs instead of fish skins to remove impurities from coffee.

Wait, so swedish fish coffee is the real deal?

In the 19th century, for sure!

Interesting! I first saw it at a state fair in the US. They mentioned Swedish immigrants too, but didn't say whether they invented the technique.

I was skeptical but...it's actually great.

Yes, that's also where the french dessert canelé comes from: the egg whites being used for wine filtering, you have a lot of yolks left. So instead of wasting them, they were/are used to make canelés.

Consomme technique.

I found this a very interesting technique when you posted it, but I actually wonder now if there is much point to it. Most of the gunk is filtered out when making a stock when you pass it through a sieve and/or a cheese cloth.

OfIs a clear broth actually something that matters besides a gate keeping technique in French cuisine?

Maybe you have specific aesthetic goals.

> Maybe you have specific aesthetic goals.

Traditional French (beef) buillon is made this way, it's presentation and taste is specifically light as it's the starter course in a multi-course meal so it's there to just whet the appetite not serve as a stand-alone meal. The way that it' finished is using the egg technique to ensure it's clarified after being passed through a cloth and chinois.

It's the same way in Japanese cooking, in order to get a proper dashi you have to ensure you don't let things get to a boil because the katsubushi or my personal favorite niboshi can break up and then ruin it entirely at those temps and it will become bitter and unusable to make soups, sauces and braises with.

So, yes, it has a purpose beyond just looks.

As already mentioned in this thread, this is done mostly for aesthetic purposes, like when making a consommé - which is judged also by how clear the liquid is, besides flavor. Other than that, you shouldn’t bother if you’re using the stock to make other dishes.

If you aren't careful with how you make your stock (e.g., including the scales and whatnot in a fish stock and cooking on higher heat levels), the egg whites will pull out some off flavors. Otherwise it's mostly aesthetics.

First thought I had : grandma used to clarify broth with eggs.

Iirc you can also use it to prepare coffee when camping. The egg binds to ground coffee in a saucepan so it’s better separated from the coffee you pour into your mug

The title just mentions microplastics, but the first line of the article says:

> a way to turn your breakfast food into a new material that can cheaply remove salt and microplastics from seawater.

So salt too? Isn't that way more impressive than microplastics? Could this lead to cheap desalination?

But then, how will you separate salt from microplastics?

Heat them up to their very distant melting points.

> "I was sitting there, staring at the bread in my sandwich," said Arnold. "And I thought to myself, this is exactly the kind of structure that we need."

Reminds me of Eli Whitney seeing a cat defeather a chicken while trying to pull it through a fence, inspiring the cotton gin (learn from nature). Wasn't the original Starlite also derived from edible matter [0]?

They started with the bread because of its spongey texture (fine, compacted flour expanding as yeast yields gas) but arrived at the egg white protein structure which is less apparent to the naked eye (the light color implies low density solid? Polar bears appear white but hair is clear, which means more empty space thus insulated?).

> Egg whites are a complex system of almost pure protein that—when freeze-dried and heated to 900 degrees Celsius in an environment without oxygen—create a structure of interconnected strands of carbon fibers and sheets of graphene.

I wonder if this rapid temperature change is embrittling the structure (squeeze with cold then stretch with heat) causing it to fragment into the "two dimensional" graphene sheets after being depleted of everything but the carbon. But the carbon fiber protein strands are cylindrical - how is this leading to flat one-atom thick sheets? Perhaps this rapid temperature gain to a specific 900C is akin to the specific resonant frequency that will shatter the crystalline structure of glass.

Robert-Murray Smith has experimented with graphitizing various natural materials like banana peels, seaweed, wood, and coffee grounds [1].

[0] https://youtu.be/0IbWampaEcM?t=256

[1] https://youtu.be/a3_XU-nva5o?t=121

Here's a slightly-critical bit...if you wanted to do this at massive scale, without inducing massive starvation:

> "Eggs are cool because we can all connect to them and they are easy to get, but you want to be careful about competing against the food cycle," said Arnold. Because other proteins also worked, the material can potentially be produced in large quantities relatively cheaply and without impacting the food supply. One next step for the researchers, Ozden noted, is refining the fabrication process so it can be used in water purification on a larger scale.

Egg whites have only been used for centuries in French cuisine as a method for clarifying liquids.

+ Aerogel. That will be $1 million dollars now please. Thank you.

The stuff seems great but one has to ask: what kind of bread is that guy eating that has egg whites in it?!

White bread is often made with egg whites to give it that super dense but fluffy/spongy texture it's famous for.

Often is a bit of an overstatement. Here in central Europe (where people think is the centre of bread culture) there is no egg and also no added sugars in 99% of all common and traditional breads.

For sure, this is specific to the quite American "white bread". Certainly not our best bread!

I've never heard that before. France and Italy, yes, I suppose to a degree - central Europe though?

Italy is not exactly famous for bread, and France more or less only for baguette and sweet bakery.

Austria and Germany are big into the bread game. With slightly different bread cultures. Switzerland too to some degree.

You'll find a German bakery in nearly any major city for a reason.

I don't think I've ever seen a German bakery anywhere, and not here in London. French, Polish and Italian bakers, yes. I know too that Poles go on ceaeslessly about how wonderful their neutronic matter rye bread is, despite it filling me with abject horror.

Horses for courses, I guess - but I've certainly no association with 'central Europe' and world-leading bread.

Interesting. Even in Bangkok premium bread had a German flag on it.

But who knows. Cultures portrait in other cultures is a complex topic.

By the way, I initially only stated that people here think it's the central of bread. I really only know a bit of how other places see things.

Certainly not in europe. I’ve never heard about German bakery. Italians on the other hand are as big masters of bread as French. Ever heard of Focaccia? Ciabatta? Pizza?!

Egg whites can be unboiled, too.

a new chemical storage for energy

https://www.science.org.au/curious/technology-future/how-and...

How about ground flax seeds? Or aquafaba?

They work in other contexts as egg substitutes…

Or that goo that surrounds chia seeds when soaked

FTA, it's a protein found in egg whites:

> Because other proteins also worked, the material can potentially be produced in large quantities relatively cheaply and without impacting the food supply.

There are vegan flocculants -- guinness switched a while back, making their beer vegan.

ovalbumin purification was a undergrad biochem lab

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

suggested but unconfirmed to have a storage as a function, so it makes sense to try its hand moving waste up its gradient

Interesting… I use egg whites to remove the sediments from the wine.

I'm really confused by this, I tried finding some videos online but it looks like they're all just mixing egg whites into their wine. How do you get the egg out of the wine?

You just mix it with the wine and it later gets precipitated like a sediment at the bottom of a vessel. Then you rack the wine, remove the naturally filtered wine juice from the vessel and leave those sediments and egg white materials at the bottom.

Why does it have to be egg white and not any other protein?

It doesn't

    "Eggs are cool because we can all connect to them and they are easy to get, but you want to be careful about competing against the food cycle," said Arnold. Because other proteins also worked, the material can potentially be produced in large quantities relatively cheaply and without impacting the food supply.

Aren't microplastics already in chickens? Do they get passed to the eggs? If so, where do you filter microplastics first. . . the chicken or the egg?

My, my, a new chicken and egg problem!

But seriously, this does raise genuine concerns about what is the acceptable limit for microplastics in the egg whites initially, since microplastics have made way to everything we consume today.

Don’t buy cheap eggs. The plastic is introduced via the feed, through vectors like expired bread products. There’s nothing wrong with using expired baked goods. The issue comes when they don’t take off the plastic wrapping and just let everything be shredded into the feed.

I do not believe grass fed chickens have the same problem.

Grass fed chickens also contain microplastics. So does every living organism these days.

What you refer to is literally feeding them plastics. Which I hope is a myth but would totally not surprise me at all.

Some animals have more microplastics than others due to their environment and other living conditions. Factory farm animals literally have plastic in their feed.

I strongly doubt they shred the plastic packaging into the feed. That said, plastic is already in everything. It's in our blood, in the placenta of fetuses. I think you'd be hard-pressed to find a chicken that doesn't have microplastics in its blood.

It's apparently not economical to separate the plastic packaging from expired product. I've seen the same happen to old packets of biscuits being shredded.

I always think environmental charities should prepare an advert against the practice with a family eating breakfast, then one person picking some plastic packaging from their teeth.

You can see a Youtube video of it happening here: https://www.youtube.com/watch?v=CSse5hX4hI4

But that video shows them separating the packaging from the food.

I may have not used the right video, I can remember watching a documentary in the UK where things weren't separated properly, and they showed pieces of blue wrapping still in the feed.

It is actually legal to do so in most states, and since it’s cheaper, you can be sure that it happens.

That's sadly a very convincing argument.

This is old news. It's a common practice that is still being done.

https://www.theguardian.com/environment/2018/dec/15/legal-pl...

There's even tiktok videos of people doing it.

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