compounds is much more difficult for blends of several varieties and from different
origins (Raieta et al. 2015).
Authentication is a term used to confirm that a claimed statement is true.
Therefore, it might be applied to olive oil, to verify whether it is “olive oil” or not,
as stated in the regulations, or whether it is “virgin olive oil” or “extra virgin olive
oil”. It can be also applied to geographical indications, to mono-variety EVOOs or to
specific products such as PDO EVOOs.
The issue of geographical origin traceability is of particular interest due to fact
that products of the same category, e.g. EVOOs, obtained from different locations
are sold at notably different prices. For these reasons, an analytical means to detect
the geographical origin would be of great importance for the industry, control bodies
and consumers.
Some studies have focused on the use of volatile compounds and cluster analysis
to find markers that could discriminate VOOs from different areas. Luna et al. (2006)
analysed 39 samples and reported successful discrimination between Italian and
Spanish VOOs based on the following compounds: 2-methylbutyl acetate, 2-methyl4-pentenal and hexanol. For the differentiation between Italian and Greek oils,
pentane-3-one, cis-3-hexenal and a hydrocarbon were reported. Regression analysis
allowed to classify oils derived from macro-areas of origin (Spain, Italy and Greece)
by the following volatile compounds: hexyl acetate, ethyl benzene, 2-methyl-4pentenal, ethyl furan, trans-2-pentenal, 1,2,3-trimethylbenzene, 3-methyl butanol
and a hydrocarbon (Luna et al. 2006).
Olive oil traceability is a complex issue, due to the interference of many factors
such as variety, year-to-year variations, agronomic practices and technological
conditions applied for the extraction that can lead to compositional variations.
Traceability and authentication require good knowledge of the composition and
characteristics of the samples, their production process and theoretically their full
history. To get a comprehensive picture and be able to build and apply a classification model to discriminate EVOOs from different geographical regions, the experimental design should include all the possible expected variability from several
years, several growing conditions and other factors that can potentially affect olive
oil composition. Many cases, in the literature, describe olive oil classification models
based on a limited number of samples, or they are based on commercial samples
whose origin is not clear, and therefore limited conclusions can be drawn. New
methods, however, have been developed over the last few years. For example, the
research field of DNA-based authentication of olive oil seems to be a new very active
area (Bazakos et al. 2016).
Major or minor compounds can be used to characterise samples, as well as several
chemometrics strategies. To reach solid classification models, correct sampling,
correct and consistent analytical methods and appropriate statistical treatment of
the data are required.
Several olive oil adulterations are still difficult to detect, despite the advanced
analytical methods available nowadays, and although methods for authenticity of
VOOs have been proposed, there are issues related to the geographical origin or
olive cultivar.
234
N. Caporaso and D. Boskou
origins (Raieta et al. 2015).
Authentication is a term used to confirm that a claimed statement is true.
Therefore, it might be applied to olive oil, to verify whether it is “olive oil” or not,
as stated in the regulations, or whether it is “virgin olive oil” or “extra virgin olive
oil”. It can be also applied to geographical indications, to mono-variety EVOOs or to
specific products such as PDO EVOOs.
The issue of geographical origin traceability is of particular interest due to fact
that products of the same category, e.g. EVOOs, obtained from different locations
are sold at notably different prices. For these reasons, an analytical means to detect
the geographical origin would be of great importance for the industry, control bodies
and consumers.
Some studies have focused on the use of volatile compounds and cluster analysis
to find markers that could discriminate VOOs from different areas. Luna et al. (2006)
analysed 39 samples and reported successful discrimination between Italian and
Spanish VOOs based on the following compounds: 2-methylbutyl acetate, 2-methyl4-pentenal and hexanol. For the differentiation between Italian and Greek oils,
pentane-3-one, cis-3-hexenal and a hydrocarbon were reported. Regression analysis
allowed to classify oils derived from macro-areas of origin (Spain, Italy and Greece)
by the following volatile compounds: hexyl acetate, ethyl benzene, 2-methyl-4pentenal, ethyl furan, trans-2-pentenal, 1,2,3-trimethylbenzene, 3-methyl butanol
and a hydrocarbon (Luna et al. 2006).
Olive oil traceability is a complex issue, due to the interference of many factors
such as variety, year-to-year variations, agronomic practices and technological
conditions applied for the extraction that can lead to compositional variations.
Traceability and authentication require good knowledge of the composition and
characteristics of the samples, their production process and theoretically their full
history. To get a comprehensive picture and be able to build and apply a classification model to discriminate EVOOs from different geographical regions, the experimental design should include all the possible expected variability from several
years, several growing conditions and other factors that can potentially affect olive
oil composition. Many cases, in the literature, describe olive oil classification models
based on a limited number of samples, or they are based on commercial samples
whose origin is not clear, and therefore limited conclusions can be drawn. New
methods, however, have been developed over the last few years. For example, the
research field of DNA-based authentication of olive oil seems to be a new very active
area (Bazakos et al. 2016).
Major or minor compounds can be used to characterise samples, as well as several
chemometrics strategies. To reach solid classification models, correct sampling,
correct and consistent analytical methods and appropriate statistical treatment of
the data are required.
Several olive oil adulterations are still difficult to detect, despite the advanced
analytical methods available nowadays, and although methods for authenticity of
VOOs have been proposed, there are issues related to the geographical origin or
olive cultivar.
234
N. Caporaso and D. Boskou