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Journal of the American Oil Chemists' Society

, Volume 93, Issue 2, pp 171–181 | Cite as

Authenticity Assessment of Extra Virgin Olive Oil: Evaluation of Desmethylsterols and Triterpene Dialcohols

  • Cynthia T. SrigleyEmail author
  • Carolyn J. Oles
  • Ali Reza Fardin Kia
  • Magdi M. Mossoba
Original Paper

Abstract

Extra virgin olive oil (EVOO) has a long history of economic adulteration, the detection of which presents significant challenges due to the diverse composition of cultivars grown around the world and the limitations of existing methods for detecting adulteration. In this study, using Method COI/T.20/Doc. No. 30/Rev. 1 of the International Olive Council, the authenticity of 88 market samples of EVOO was evaluated by comparing total sterol contents, desmethylsterol composition, and contents of triterpene dialcohols (erythrodiol and uvaol) with purity criteria specified in the United States Standards for grades of olive oil and olive-pomace oil. Three of the 88 samples labeled as EVOO failed to meet purity criteria, indicating possible adulteration with commodity oil and/or solvent-extracted olive oil. Detection of adulteration was also evaluated by spiking an EVOO sample with commodity oil at the 10 % level. As expected, eight of the spiked samples (canola, corn, hazelnut, peanut, safflower, soybean, and sunflower oils, and palm olein) failed to meet purity criteria. Two of the three samples spiked with 10 % hazelnut oil went undetected for adulteration. Overall, a low occurrence rate of adulteration (<5 %), based on purity criteria for desmethylsterols and triterpene dialcohols, was detected for the 88 products labeled as EVOO.

Keywords

Adulteration Authenticity Desmethylsterol Erythrodiol Extra virgin olive oil Gas chromatography Purity Sterol Triterpene dialcohol Uvaol 

Abbreviations

ANOVA

Analysis of variance

AOCS

American Oil Chemists’ Society

BSTFA

N-O-bis(trimethylsilyl)trifluoroacetamide

CAS

Chemical Abstracts Service

EVOO

Extra virgin olive oil

FDA

United States Food and Drug Administration

GC-FID

Gas chromatography with flame ionization detector

IOC

International Olive Council

IS

Internal standard

SD

Standard deviation

SRM

Standard reference material

TCF

Theoretical correction factor

TLC

Thin layer chromatography

TMSE

Trimethylsilyl ether

USDA

United States Department of Agriculture

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Copyright information

© AOCS (outside the USA) 2015

Authors and Affiliations

  • Cynthia T. Srigley
    • 1
    Email author
  • Carolyn J. Oles
    • 1
  • Ali Reza Fardin Kia
    • 1
  • Magdi M. Mossoba
    • 1
  1. 1.Center for Food Safety and Applied Nutrition, United States Food and Drug AdministrationCollege ParkUSA

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