Protein Isolates


#1

What do people think of this? Are solvents used in Soylent? Which ones?

Protein isolates are highly processed, highly concentrated proteins that are rampant in refined foods – including protein powders, bars, and shakes – and there are lots of them. Soy protein isolate, whey protein isolate, pea protein isolate, wheat protein isolate, just for starters. In my opinion, any protein that’s been “isolated” from its original food source is patently unhealthy. Why? In a nutshell, protein isolates are extracted from their original food source through a refining process involving molten heat and solvents (often hexane or lye, trace amounts of which remain in the product) that denature the protein. Many of these isolates also have other toxic additives to “enhance” their flavor. Avoid them all! To learn about protein isolates and other unhealthy proteins such as hydrolyzed protein and textured vegetable protein (aka “TVP”), watch…


#2

That’s downright hilarious… A. Molten heat? Molten what? Molten butter? Molten ice? B. Hexane? I’d be impressed if you could find any traces nowadays C. Trace amounts of Lye sounds bad doesn’t it? Lye is just a base, potassium hydroxide. Which means… It’s a hydroxide + Potassium. Which when dissolved in water is… water and potassium basically. Now the PH is the real issue, as very high or Low PH would burn you. But a trace amount would mean that your solution contains Potassium and Water… and a ph of 7.001 instead of 7.000.

If I poured Potassium hydroxide (lye) along with hydrochloric acid into a bottle… and after it cooled down as long as the PH was between 6-8… it would be safe to drink… because it would be salt water.


#3

Since when is salt water safe to drink?


#4

When it’s not as salty as sea water and not your only source of hydration.

To the OP not all protein isolates are processed that way. I don’t know or care if the protein in Soylent is processed that way. This seems like typical Internet BS. Maybe if you found more and more credible sources?


#5

Anything found in nature is inherently good for us, because nature designed everything specifically to suit our needs. Didn’t you know? Nature cares about us.

Anything man made is obviously bad for us, because humans design things to hurt other humans.


#6

Right now we have been using some fairly advanced technology to produce protein isolate, for example, some brown rice protein isolate uses enzymatic extraction which does not involve high heat and it’s completely natural. Good quality whey protein isolate uses cross flow micro-filtration (cold pressed) which again does not involve heat and the protein is never denatured.


#7

TIL chicken noodle soup is a toxic substance.


#8

And what’s even worse is these people aren’t even communists, they’re making money by selling things people want to buy!


#9

Cody’s Lab (YouTube channel) even has a video using (diluted) Lye as a condiment to reduce the sour taste of foods. https://www.youtube.com/watch?v=Nj46HrNmy2w

Something I’ve wondered for a while, does the body need the proteins in food to be in their functional state? In just about every discussion of protein I see someone saying, “don’t heat that,” or “don’t add acid to that.” Sure, the proteins in our bodies are performing a task, and their shape is what makes them work. But aren’t we ingesting proteins just to carve them up and rebuild them into the stuff we need? Might it be that enzymes in our digestive tracks need the protein to be of a specific shape to make their work easier? But at the same time wouldn’t the acid in our stomach work to denature the proteins to start?

Any molecular biologists here to give an authoritative answer?


#10

Well, don’t we cook meat and eggs? Don’t we boil milk? These are all protein sources.


#11

There are plenty of carnivores and ovivores, and all mammals feed milk to their young, but we’re the only ones who heat those things first. What I’m wondering is, if it weren’t for the food safety issues, would it be better if we didn’t?


#12

um no.
cooking makes things more digestible, which is key to being an omnivore. humans eat a wider variety of things because of that,
which makes us so robust we’ve taken over the planet.
eating raw meat = short digestive tract,
eating fibrous plants = long digestive tract.
ours is in the middle.
we cook vegetables so that our “short” digestive tract is long enough,
we cook meat so that our “long” digestive tract is short enough.


#13

I’m pretty sure you’re right, and you definitely are for general makeup of the food. Especially about making plants more digestible. But this is specifically about proteins, and how they are best presented for use by the body. I’d really like for someone with a chemistry background to explain how the body turns a protein-complete meal into what we need. How the proteins are cleaved and reassembled, and is that process made more difficult by denaturing the proteins before ingestion. Obviously we can use tightly coiled proteins that are no longer functional, but is it easier if we don’t.

I’m sure someone knows exactly, but I’ve never actually seen the full process written down. I mostly want this reference so I can point to it every time I see someone talking about denatured proteins.


#14

I think bears would disagree.

We cook our food because it was extremely advantageous to do so (killing pathogens). Some of our ancestor found cooked food to be easier to digest and thus found it even more advantages to cook their food. Now after thousands of years we have evolved to need to cook our food. We can no longer get enough calories from raw meats and (wild) fruits and vegetables. Wild animals, like chimps, don’t have this problem because their digestive systems didn’t evolve that way. They can get more calories from their foods than we can.


#15

Related: Why Calorie Counts Are Wrong: Cooked Food Provides a Lot More Energy


#16

That is correct. Proteins we eat are broken down to amino acids; this process is technically called “degradation,” but that shouldn’t imply anything bad. It simply means that the proteins are broken down into the basic building blocks. The digestive system then uses transporters to move them into the blood. The blood carries them around the body, and the body then builds the proteins it needs out of those basic building blocks.

So the shape of eaten proteins is irrelevant to the body; the proteins will be broken down for scrap.

Note: if there is a medical therapy that uses proteins injected into the blood, shape may matter. Also, there are also other substances that we may consume orally where shape may matter - this is known with some chemically synthesized compounds, including synthetic stereoisomers of tocopherols (Vitamin E) - but that list of things doesn’t include proteins, which are all broken down to base amino acids, and the base amino acids do not have a shape.

Tracts. And yes, exactly! The enzymes do require a specific shape: unwound. The technical name for the process of unwinding a protein blob is called “denaturing,” because it takes it from the naturally occurring blob into a more useful state to work on.

Denaturing is the unavoidable first step in protein digestion. If the protein is not denatured (or partially denatured) ahead of time, then the digestive system simply has to do more denaturing work before the enzymes can get busy on the proteins.

Oh, dear. I feel like you’ve invited a windbag to talk.

Proteins can be denatured into a workable strand, or can be renatured into a coiled blob; the body does both: it denatures proteins that it’s going to break down, and it renatures proteins that it creates to use for biological functions. We’ll ignore renaturing here.

Balled chains of amino acids are held in their coiled shapes by hydrogen bonds between unconnected amino acids links; the hydrogen bonds “tie” different parts of the chain together. A close pattern of hydrogen bonds makes a coil; other hydrogen bonds across different sections cause cross-links. All together, they make a blob out of the protein.

Denaturing breaks the hydrogen bonds, allowing it to uncoil, but the aminos in the chain are unchanged.

There are three main methods that denature proteins:

1. Heat. Heat can make the blob relax and uncoil. This is why cooked food is far more digestible… but our bodies also use some heat; whatever we eat gets heated up to 98.6f. Heat is why a cooked egg turns solid-ish, though still gooey; the uncoiled proteins turn into filaments that can tangle together, like this:

Even though the cooked protein is a tangled mess, it’s still much more digestible than those little knots it started out as; more on that later.

2. Chemistry. Acids, bases, alcohols, salts - all of these can denature proteins. Our bodies use a lot of acids in the digestive tract for this purpose; it’s our workhorse mechanism.

3. Violence! Proteins can be physically denatured if you’re aggressive enough. Example? When you whip egg whites, you don’t just inject air. You’re actually busting up the little protein blobs into long protein chains. These long chains (some of which can then cross-link to each other) give the whipped egg whites their stiffness and cause the mixture to retain some air, looking much like the cooked protein above, but fluffier.

Then, proteolysis. No matter how the protein gets denatured, it’s only after the protein is unwound that enzymes can finally go to work on them, breaking them down. Breaking proteins into pieces is called proteolysis, It goes kinda like this:

The proteolytic enzymes are the enzymes that hack long amino acid chains (proteins) into smaller pieces. Some of the pieces are single aminos; others are still chains. An oligopeptide is a chain of amino acids which is quite short (20 links or less; most proteins in nature are hundreds of aminos long.)

An intestinal cell can take in a single amino acid, or can take in an oligopeptide, but longer chains are too big and stay in the digestive tract until digestive enzymes have broken them down further. Single amino acids are easy, but the intestinal cell makes use of an enzyme called aminopeptidase to break oligopeptides down into dipeptides and tripeptides as they’re taken into the cell. A dipeptide (two) or a tripeptide (three) is basically a chain of two or three amino acids.

Once inside the intestinal cell, single amino acids can be transferred directly from the intestinal cell to the blood, but those chains of two or three aminos can only be absorbed with the help of peptidase enzymes, which break down the final links in the chain while they’re handed off to the blood. The blood gets single aminos; that’s what the body uses.

But the key thing is that none of the enzymes can go to work on the proteins until they are uncoiled; a.k.a., denatured. It all starts there.

Fun references (and the sources of these images):
https://scienceandfooducla.wordpress.com/2013/03/26/ceviche/ http://www.ncbi.nlm.nih.gov/books/NBK22600/

Final note: this is also why proteins from GMOs are as safe as “natural” sources; no matter the composition and shape of the proteins, we break them down to base aminos in our digestion. Now, that’s not to say GMOs are inherently safe - there’s always the question of what the proteins in question do. For example, if a GMO plant has proteins which allow it to produce an insecticide, then the protein that codes the insecticide may be harmless to us, but the insecticide it produces may not be (it’s certainly not harmless to insects!) So, is there any insecticide left in the plant when we get it? And is that insecticide harmful to us?

GMO organisms need to be carefully designed for function, and need to be tested, and we need to be careful about how they interact with native species if they get out in the wild… but they are inherently made of the same building blocks, and so their proteins are as safe as anything else we eat.


#17

No. That was exactly what I’ve always wanted to read. :slight_smile: I had a rough feeling that was the way things worked from Bio and Chem 101 (I was a Computer Science major so I only got a cursory glimpse into this world). You explained it perfectly.


#18

Highly recommend Crash Course: Anatomy & Physiology #33-37