Saturday, March 19, 2011

Chemistry: Polysaccharides

I need to break for an aside here on the chemistry of polysaccharides as this is coming up more and more as I research our cosmeceuticals.

What are polysaccharides? They are "polymeric carbohydrate structures formed of repeating units joined together by glycosidic bonds" (from Wikipedia). We can find quite basic ones like two monosaccharides like glucose and fructose joined together to make sucrose or D-galactose and D-glucose joined together to make lactose (the picture above and bane of my existence!). We can find more complicated ones like starch, glycogen, cellulose, xanthan gum, guar gum, hyaluronic acid, and so on. We find a lot of polysaccharides in bath and body ingredients, so it's useful to know what they do.

In general, we use ingredients with polysaccharides as healing, soothing, and skin protecting qualities as they reduce irritation and can create a barrier between our skin and the outside world.

Some polysaccharides are considered mucilagenous, meaning they contain mucilage. Mallow, liquorice, and aloe vera all contain mucilage and this gooey stuff can create a film on our skin to protect us while soothing and reducing inflammation. (As Alton Brown calls it in his episode on okra, it's SLIME!) We can make a form of hair gel by soaking flax seed because of this slime and you can find it in chia seeds and carageenan.

Some polysaccharides are starches - like tapicoa, corn, and arrowroot powders, to name a few. These starches can be used alone in products like dusting powders that can help absorb liquids and prevent chafing, or can be included in our products to bind and thicken, like Dry-Flo. In these cases, the polysaccharides offer the skin protecting, soothing, and healing qualities as well as adding thickness (and often increasing that dry feeling) to the products.

We also find polysaccharides like xanthan gum (picture to the left), guar gum, cationic guar gum, and cationic hydroxyethylcellulose (HEC) that will thicken our products and offer that light film forming. These tend to be quite complicated molecules that can create a film on your skin and make things like lotions, shampoos, conditioners, and other water based products thicker.

And some are humectants, like hyaluronic acid (scroll down a bit after clicking). As a note, glycerin is not a polysaccharide, it's a glycerol.

So if you see that an ingredient like beta glucan or sea kelp bioferment contains polysaccharides, you can extrapolate that this will be an ingredient that offers film forming and skin soothing properties. It may or may not add thickness to the product and that's something to investigate when you are considering the viscosity of a product.


still learning said...

Sorry that my upcoming question is a bit off topic but I didn't know what would be a good article to post it. Does anyone know what does NLT mean? I see this sometime when looking at a material safety data sheet. When I try to research it I get things related to internet slang and the bible. Below is an example of what I'm talking about with this NLT or HMT stuff.

Thanks Everyone.

NLT 90 % through 80 mesh-size.

NLT 10 % glycyrrhizic acid

Ash Content:
NMT 5 %

Moisture Content:
NMT 5 %

He's an ANGEL said...

Kinda late but,
NLT = not less than
NMT = not more than

Heela said...

I have been trying to look for directions on how to use Dry-Flo TS in lotion to get rid of that "greasy" feeling. I read on your blog that you add it to the water phase. My lotions were coming out a bit weird and I went to the manufacturer this time to figure things out. The manufacturer's formulations indicate you should add Dry-Flo TS to the cool down phase. Thought this might help anyone else who had the same question. Also, it worked out amazingly.

Susan Barclay-Nichols said...

Hi Heela! I've written a post about this topic, which you can find here on Sunday, March 9th. Dry Flo TS is a different product than Dry Flo AF, which is the ingredient I use. Thanks for giving me something to write about today!

Kavya said...

Hi Susan, I have a question about making flax seed gel for hair. I make flax seed gel at home by boiling flax seed in water. But it is not very smooth to apply as it turns out into kind of pulp. Most marketed hair gels that contain linseed extract as the main ingredients to provide the hold for example Jessicurl rocking ringlets have very smooth consistency. So my question is, can you guess in what form they use the linseed extract to achieve that consistency?

Susan Barclay-Nichols said...

Hi Kavya. I did a quick search for linseed extract and came up with all kinds of hits. I encourage you to do a search as there's a ton of information out there, and I'm not sure where to start for you.