ARS | Publication request: AUTHENTICATION OF COMMERCIAL GRAPEFRUIT SEED EXTRACTS

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: December 28, 2004
Publication Date: March 13, 2005
Citation: Takeoka, G.R., Dao, L.T., Wong, R.Y., Harden, L.A. 2005. Authentication of commercial grapefruit seed extracts. Meeting Abstract. AFGD Paper No. 50, ACS Nat'l Meeting, March 2005, San Diego, CA.

Technical Abstract: Grapefruit seed extract (GSE) is promoted as a natural product that has reported antibacterial and antiviral properties. It is reported to be safe and effective to use internally and externally for a wide variety of conditions such as acne, allergies, athlete's foot, body odor, candida, colds, cold sores, gastrointestinal infections, gingivitis, impetigo, parasitic infection, sinusitis, sore throat and thrush. There is recent evidence that some commercial GSE samples are adulterated with synthetic preservatives and that these additives are solely responsible for the antimicrobial activity. Preservatives such as methyl 4-hydroxybezoate (methyl paraben), 2,4,4'-trichloro-2'-hydroxydiphenyl ether (triclosan) and benzethonium chloride have been identified in commercial GSE samples. In this paper we will report the characterization of a new adulterant in commercial GSE samples using HPLC, electrospray ionization mass spectrometry (ESI/MS), tandem mass spectrometry (MS/MS) and elemental analysis (by proton induced X-ray emission [PIXE] analysis).