Tuesday, November 5, 2013

Meadofoam seed oil: Why is it so stable?

The picture to your left is of the conjugated linoleic acid molecule. You can see there's a difference between the eicosenoic acid bonds and the conjugated linoleic acid bonds. So what does this mean?

From this post on conjugated linoleic acid: A conjugated molecule is an organic compound is one where atoms covalently bond alternating single and double bonds that influence each other to produce a region called the electron delocalization. In this region, electrons do not belong to a single bond or atom but to a group.

Very nice but what the heck does this mean for us? A conjugated linoleic acid is like linoleic acid in that it has 18 carbons with two double bonds, but we see the trans and cis configurations in there making the fatty acid all twisted instead of a nice straight line. The cis configuration means the molecules won't lie down nicely, so this oil is going to be slightly thicker than one filled with nice straight molecules like those we find in a trans molecule. (See the molecule above!)

What this means is that a fatty acid like conjugated linoleic acid will have bonds that break easier than those in meadowfoam seed oil, and broken bonds leads to rancidity, meaning a fatty acid with this kind of composition will go rancid or have a shorter shelf life than one without these kinds of bonds. Since meadowfoam seed oil's bonds are harder to break, it'll have a longer shelf life than other oils.

The eicosenoic or gadoleic acid is the main way this oil retards rancidity in itself and other oils. I've seen it noted that that "the absence of high levels of oxidation-sensitive polyunsaturated fatty acids" and to the "presence of anti-oxidants such as 1,3-di(3-methoxybenzyl) thiourea". In other words, there are good things that help prevent rancidity and there is a lack of things that might go rancid quickly, like those polyunsaturated fatty acids with those easy to break bonds. It's noted that the eicosenoic acid is five times more stable than oleic acid and sixteen times more stable than other monounsaturated fatty acids. Now that's incredibly stable!

Want to know more about 1,3-di(3-methoxybenzul) thiourea? Check out this Powerpoint!

Related posts:
Rancidity: A primer
Mechanisms of rancidity
More links on rancidity and contamination

Data sheet from Brenntag Specialties
Quick summary page from Brenntag Specialties
Interesting article comparing jojoba and meadowfoam seed oils
Page 140, The Biological Activity of Photochemicals

Join me Thursday as we start formulating a few things with this fascinating oil!


p said...

I've been wondering about why meadowfoam seed oil is so stable -- thanks for this post!

I find it strange that the reason it is said to extend the shelf life of other oils, is because of its antioxidants. So many oils contain high levels of antioxidants, but they don't get the same praise!

Susan Barclay-Nichols said...

Hi p! I agree with you. Look at soy bean and wheat germ oils - they're pretty high! - so why does meadowfoam seed oil get all the glory? I think it's because it does. Yeah, terrible answer, but don't you find that when you start looking at something more closely, it almost always ends up that the claims for the oil aren't substantiated well or at all?

p said...

I was just thinking the same thing, Susan! Reminds me of bananas and potassium. Somewhere a meadowfoam seed oil PR person is steepling their fingers and chuckling, a la Mr Burns... :)

Anonymous said...

Wow - I love Meadowfoam Seed Oil neat. Tried it 2 days in a row now.
I am revisiting the formulating body oil spray section and the amazing section on your blog regarding the skin fee of oils.
I remember you encouraging your readers to try oils neat and for me this has been extremely valuable information because its the only way I can determine if I really like a particular oil.Going to try making an oil spay using this oil and Fractionated Coconut Oil see how that works.
Looking forward to seeing your Thursday post.
- Beth

Susan Barclay-Nichols said...

Hi p! Excellent....

Hi Beth! I'm really loving this oil, too!

Saj said...

Hi! I just found this blog and am so thankful for so much information. I am starting to make products and I see that you say you can use up to 5% Meadowfoam to stabalize other oils. I was wondering if Instead of putting meadowfoam seed in each product I would like to add meadowfoam to the gallons of oils - is 5% the minimum that I have to put for it to work? Thanks!!

Susan Barclay-Nichols said...

Hi Saj. I can't speak to using it with large amounts of oil, unfortunately. You could try it, then keep records documenting how long your oils last with it.