README file
Data Set Title: OLEUM project. Analysis of volatile compounds of extra virgin and virgin olive oil with a different geographical origin by flash gas chromatography
Data Set Authors: Rosa Palagano (University of Bologna); Alessandra Bendini (University of Bologna); Enrico Valli (University of Bologna); Chiara Cevoli (University of Bologna); Tullia Gallina Toschi (University of Bologna). 
Data Set Contact Person: Alessandra Bendini, http://orcid.org/0000-0002-6515-5519, alessandra.bendini@unibo.it.
Data Set License: this data set is distributed under a Creative Commons Attribution 4.0 International (CC BY 4.0) license, https://creativecommons.org/licenses/by/4.0/.
Publication Year: 2019
Project Info: OLEUM (Advanced solutions for assuring the overall authenticity and quality of olive oil), funded by European Union, Horizon 2020 Programme. Grant Agreement num. 635690; http://www.oleumproject.eu/.  
Data set contents
The data set consists of:
•	Two numerical quantitative files, each one saved in .xlsx and .ods formats 
o	“OLEUM_Geographical_origin_FGC.xlsx”
“OLEUM_Geographical_origin_FGC.ods”
o	“OLEUM_Geographical_origin_Matrix_FGC.xlsx” *
“OLEUM_Geographical_origin_Matrix_FGC.ods” *
* These files cannot be openly shared because they contain data that are in course of elaboration by other statistical approaches, with the aim of possibly publishing the results and exploiting them. They will be made available only upon motivated request.
•	a README file saved in .rtf format
“OLEUM_Geographical_origin_FGC_README.rtf”
Data set Documentation
Abstract
This data set contains the underlying data of the scientific publication:
Palagano R. et al., 2020. Compliance with EU vs. extra-EU labelled geographical provenance in virgin olive oils: A rapid untargeted chromatographic approach based on volatile compounds. LWT - Food Science and Technology, 130, 109566. https://doi.org/10.1016/j.lwt.2020.109566.
To ensure that consumers are not misled, the European Regulation n. 29/2012 establishes specific rules to report the geographical origin of extra virgin and virgin olive oils (VOOs) on the product label, but an analytical procedure to verify this information is not defined. 
A flash gas chromatography and untargeted chemometric data elaborations for the rapid screening of 210 extra virgin and virgin olive oils with a different geographical provenance was applied. The analysis of volatile compounds was carried out by the Flash Gas Chromatography Electronic Nose Heracles II (Alpha MOS, Toulouse, France). The instrument was equipped with two metal capillary columns (MXT-5 and MXT-1701) working in parallel mode. At the end of each column, a FID detector was placed and the acquired signal was digitalized every 0.01 sec.
This data set contains the raw data (intensity values for each point of the chromatogram considering that the signal was digitalized every 0.01 sec) obtained from the analysis of all the sample by flash gas chromatography. Only data obtained from the column MXT-5 are reported since this column showed a higher discriminating power.  
Content of the files 
•	“OLEUM_Geographical_origin_FGC.xlsx / .ods”
o	The sheet named “Sample category” contains information about the category of each sample according to their geographical origin.
o	The sheet named “Y data for PLSDA” contains the Y references values 0 or 1 used to build the PLS-DA quality grades models.
•	“OLEUM_Geographical_origin_Matrix_FGC.xlsx / .ods” 
The sheet named “X matrix for PLSDA model” contains the raw data (X values used to build the PLS-DA models therefore intensity values for each point of the chromatogram considering that the signal was digitalized every 0.01 sec) of each sample analyzed. Data were exported from the instrument and used for a chemometric elaboration. Values are mean of three replicates.  
File specifics
To create the .ods files, “LibreOffice Calc” version: 6.3.6.2 was used.