I use Grapefruit Seed Extract as my preservative because it is natural. But is it?
Grapefruit Seed Extract is an interesting beast and one that I became aware of in the early days of my life as a cosmetic chemist. I wasn’t aware back then in 1998 of the issue that preservation would pose for brand owners as the natural revolution (or evolution) was only just beginning to hit the mainstream but these days I can’t get through a week without someone enquiring after ‘safe and natural and preferably nice sounding’ preservatives. I would be lying if I didn’t admit to it driving me a little nuts at times……
The problem with Grapefruit Seed Extract is that it isn’t just the hand-squeezed juice from grapefruit seeds (can you even do that by hand?) True grapefruit seed extract preservative is a clever mix of marketing, INCI name choice and chemical genius as partially uncovered by the guys here at Natural Ingredient Resources in their interview with one grapefruit seed extract manufacturer trade name ‘Citracidal’.
In the above interview we get to the heart of the matter and on reading a number of other scientific papers we get a bit more meat on our bones.
Grapefruit seed extract as a freshly squeezed juice as you will is woefully bad at acting as a preservative, so bad that you have to add between 4-20% to a formula to get it to record any benefit in terms of micro reduction. That is not a sensible plan and would severely impinge on the Chemists ability to create novel, interesting and cost-effective products. The grapefruit seed its self works like many other natural extracts and essential oils by being rich in naturally occurring microbe-fighting polyphenolic compounds.
‘The phenols found in essential oils normally have a carbon side chain and here we can look at compounds such as thymol, eugenol and carvacrol. These components have great antiseptic, anti-bacterial and disinfectant qualities and also have greatly stimulating therapeutic properties.
Due to the nature of phenols, essential oils that are high in them should be used in low concentrations and for short periods of time, since they can lead to toxicity if used over long periods of time, as the liver will be required to work harder to excrete them.
Phenols are also classified as skin and mucus membrane irritants and although they have great antiseptic qualities, like cinnamon and clove oil, they can cause severe skin reactions.’
Polyphenols are phenolic compounds (chemicals based on phenol) and there is a great description of those here on Wikipedia including some examples. Plants use polyphenolics as antioxidants and antioxidants can help to preserve a product by preventing it from degrading, some even have anti-microbial powers.
Both the phenols and their polyphenolic sisters are put to good use in cosmetics as active components in many natural extracts for their UV protective power, their anti-microbial efficacy, their antioxidant abilities and sometimes even their aroma so it is fair to say that phenolics are both useful and important to the cosmetic chemist. But they can be irritating and as such we have to take care not to use more than we have to – the double-edged sword of the active chemical!
But it isn’t these naturally squeezed phenolics that are doing the heavy lifting work in the preservative grade Grapefruit Seed Extracts!
Phenols are a group of organic chemicals (organic as in contain carbon rather than grown) that contain a BENZENE ring. This benzene ring presents an opportunity to the chemist who can use it to create a whole host of other chemicals as benzene rings are quite reactive and relatively easy to manipulate.
Taking advantage of the naturally occurring benzene ring that exists in Grapefruit Seed Extract and turning it into something different – in this case a QUAT (benzethonium chloride) is smart but in my book that no longer makes it capable of being called natural UNLESS the process chemicals conform to natural standards – possible but maybe not quite as simple, green and clean as many had thought.
I think we have been sold a bit of a story here guys……..
Chemically altering nature to create a new ingredient is, in my book the very definition of a synthetic process. The fact that the resulting chemical has been given the INCI name of grapefruit seed extract is marketing genius.
Here is a link to the main active anti-microbial agent in preservative grade Grapefruit Seed Extract. It is a good preservative but we should keep in mind that it should be present at 0.1% as a maximum to prevent irritation. It is also important to note that being a Cationic will mean that it is not suitable for use in formulations containing Anionics – check your emulsifiers and surfactants! It is also not suitable for use in oral care.
I’m not saying don’t use Grapefruit Seed Extract, I use it myself in some situations but I am saying that maybe we should ask a few more questions about what is in the Grapefruit Seed extract that is working before we decide it fits our natural, pure and safe philosophy as it might just be that there are better alternatives out there.