Grapefruit Seed Extract Studies

[Guest guest]

Hi Josh,

Funny you should ask about studies on this, I was just putting together a

newsletter and including info Grapefruit Seed Extract. Below are the studies I

have come across,

 

Pat

 

 

Identification of benzethonium chloride in commercial grapefruit seed extracts.

 

Takeoka G, Dao L, Wong RY, Lundin R, Mahoney N. J Agric Food Chem. 2001

Jul;49(7):3316-20.

 

Western Regional Research Center, Agricultural Research Service, U.S. Department

of Agriculture, 800 Buchanan Street, Albany, California 94710, USA.

grt

 

Commercial grapefruit seed extracts (GSE) were extracted with chloroform. The

solvent was evaporated, and the resulting solid was subsequently analyzed by

high-performance liquid chromatography, electrospray ionization mass

spectrometry, nuclear magnetic resonance (NMR) spectroscopy, and elemental

analysis (by proton-induced X-ray emission [PIXE] analysis). The main

constituent was identified as benzethonium chloride, a synthetic antimicrobial

agent commonly used in cosmetics and other topical applications. This compound

comprised 8.03% (n = 2) of the liquid GSE sample. Higher amounts of benzethonium

chloride were found in powder GSE samples.

 

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Aspects of the antimicrobial efficacy of grapefruit seed extract and its

relation to preservative substances contained.

 

von Woedtke T, Schluter B, Pflegel P, Lindequist U, Julich WD.

Pharmazie. 1999 Jun;54(6):452-6.

Institute of Pharmacy, Ernst Moritz Arndt University, Greifswald, Germany.

 

The antimicrobial efficacy as well as the content of preservative agents of six

commercially available grapefruit seed extracts were examined. Five of the six

extracts showed a high growth inhibiting activity against the test germs

Bacillus subtilis SBUG 14, Micrococcus flavus SBUG 16, Staphylococcus aureus

SBUG 11, Serratia marcescens SBUG 9, Escherichia coli SBUG 17, Proteus mirabilis

SBUG 47, and Candida maltosa SBUG 700. In all of the antimicrobial active

grapefruit seed extracts, the preservative benzethonium chloride was detected by

thin layer chromatography. Additionally, three extracts contained the preserving

substances triclosan and methyl parabene. In only one of the grapefruit seed

extracts tested no preservative agent was

found. However, with this extract as well as with several self-made extracts

from seed and juiceless pulp of grapefruits (Citrus paradisi) no antimicrobial

activity could be detected (standard serial broth dilution assay, agar diffusion

test). Thus, it is concluded that the potent as well as nearly universal

antimicrobial activity being attributed to grapefruit seed extract is merely due

to the synthetic preservative agents contained within. Natural products with

antimicrobial activity do not appear to be present.

 

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[Analysis of components in natural food additive " grapefruit seed extract " by

HPLC and LC/MS]

 

Sakamoto S, Sato K, Maitani T, Yamada T.

Eisei Shikenjo Hokoku. 1996;(114):38-42.

 

The components in a commercial natural food additive " Grapefruit seed extract "

and the ethanol extract of grapefruit seeds were analyzed by HPLC and LC/MS. The

HPLC chromatogram of the commercial grapefruit seed extract was quite different

from that of the ethanol extract of grapefruit seeds. Three main peaks were

observed in the chromatogram of the commercial grapefruit seed extract. By

comparison of the retention times and the absorption spectra with those of

authentic samples, two peaks were ascribed to methyl-p-hydroxybenzoate and

2,4,4'-trichloro-2'-hydroxydiphenylether (triclosan). Triclosan was also

identified by LC/MS by using the negative electrospray ionization method.

 

 

 

[donetta]

Concerning an article posted about studies done on grapefruit seed extracts

you said,

 

"In only one of the grapefruit seed

extracts tested no preservative agent was

found".

 

Could you please tell me which one that was?

 

Thanks, Donetta