Guest guest Posted July 11, 2005 Report Share Posted July 11, 2005 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. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [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. Quote Link to comment Share on other sites More sharing options...
donetta Posted November 23, 2010 Report Share Posted November 23, 2010 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 Quote Link to comment Share on other sites More sharing options...
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