It might seem like a lovely all-natural ingredient, and with it's powerful antimicrobial properties I thought GSE could be a great way to preserve my fresh creams. But, on a closer look, I discovered that unfortunately grapefruits in their natural form have been shown to have no antimicrobial activity… so how can this be?
Grapefruits go through a whopping 7-step process to become grapefruit seed extract. During this process, various chemical reactions occur, resulting in the GSE being mostly made up of the synthetic preservatives benzethonium chloride and benzalkonium chloride (used in cleaning products, and known to cause severe skin and respiratory irritation).
Other synthetic preservatives that can be found are:
Regulations need to step up as GSE is still being widely sold and used in "all-natural" products, despite the evidence against it. All cosmetic products in the UK containing water are required to undergo rigorous preservative efficacy testing before being sold on the market. It's easy to fall into the trap and use an ingredient that is not actually natural but is almost guaranteed to pass the tests, while still labelling your products as "all-natural", but you can see how this is clearly exploiting the consumer.
1. The effectiveness of processed grapefruit-seed extract as an antibacterial agent: I. An in vitro agar assay.
2. Antimicrobial activity of grapefruit seed and pulp ethanolic extract.
3. Aspects of the antimicrobial efficacy of grapefruit seed extract and its relation to preservative substances contained.
4. The Truth about Grapefruit Seed Extract.
5. Development and validation of an HPLC/UV/MS method for simultaneous determination of 18 preservatives in grapefruit seed extract.
6. Adverse effects by artificial grapefruit seed extract products in patients on warfarin therapy.
7. Presence of chemical additives and microbial inhibition capacity in grapefruit seed extracts used in apiculture.