Natural Antioxidants


Antioxidants get a lot of interest for the skin benefits, but for a cosmetic chemist they also have a rather more mundane use.  If you are using natural ingredients in your products, and particularly some natural oils, you need to give some thought to the risks of  oxidation of the product over its shelf life.  Left to themselves many oils will go rancid, which gives them an unpleasant odour and often affects the colour.  Consumers love natural products in principle, but aren’t keen on being presented with brown smelly ones.  It is a shame to mess up a natural story by including chemical antioxidants, so what are the natural antioxidant alternatives?

There is one rather obvious one, which is vitamin E.  This works pretty well, and indeed is the skin’s own workhorse antioxidant.  Vitamin E has been used very successfully for many years and will no doubt continue to be used.  The name on the ingredient list is tocopherol.

But an interesting alternative has been developed by an American food company called Kemin.  They have a lot of expertise in crop selection, and with a bit of judicious application of botany and chemistry have come up with a new antioxidant. It is derived from a specially variety of Rosemary and they are selling it under the trade name Rosamox.  This sounds like just the sort of thing that GM technology comes up with, but they used conventional breeding techniques.  GM is not the bogeyman that some people make it out to be, but it is good to be reminded that there is still quite a lot that can be done without it.

The thing with antioxidants is that there is no really good theoretical way to predict how well they will work, and some work better for some applications than others.   The antioxidants are effectively sacrificial lambs, drawing the oxidising free radicals away from where they can do the damage.  It sounds simple enough, but working out the best option can be a tricky business.   The details of how a particular oil reacts in a particular formulation can be quite complicated.

One test is to heat the oil up and measure how quickly chemicals called peroxides develop. The more peroxide, the more damage the oil has suffered.  So you can use this test to see what level of antioxidant you need, and which antioxidant works the best.  Rosamox is claimed to work better than vitamin E in this test.  This doesn’t necessarily mean it will work better for every application, but it does mean that it is worth considering.

I find it pleasing to see products like this appearing.  I don’t subscribe to the idea that synthetic is bad and natural is good.  But I do like to see a bit of creativity and science working together to come up with new products that can be produced sustainably and which offer some real benefits.

Thanks to John Darbyshire of Adina for his help with this post.


Photo credit: fturmog via photopin cc

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