README file

Data Set Title: OLEUM Project. Portable system for the determination of free acidity in virgin olive oil. Data from in-house validation

Data Set Authors: Marco Grossi (University of Bologna); Rosa Palagano (University of Bologna); Alessandra Bendini (University of Bologna); Bruno Riccò (University of Bologna); Maurizio Servili (University of Perugia); Diego Luis García-González (Instituto de la Grasa - CSIC); Tullia Gallina Toschi (University of Bologna). 

Data Set Contributor: Enrico Valli (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:
•	a numerical quantitative file saved both in .xlsx and .ods formats 
“OLEUM_PortableFreeAcidityDetermination_VOO.xlsx”
“OLEUM_PortableFreeAcidityDetermination_VOO.ods”
•	a README file 
“OLEUM_PortableFreeAcidityDetermination_VOO_README.rtf”

Data set Documentation

Abstract
This data set contains the underlying data of the scientific publication:
Grossi M., Palagano R., Bendini A., Riccò B., Servili M., García-González D. L., Gallina Toschi T. (2019). Design and in-house validation of a portable system for the determination of free acidity in virgin olive oil. Food Control, 104:208-216, https://doi.org/10.1016/j.foodcont.2019.04.019.
The quality of virgin olive oil - in terms of belonging to a specific quality grade (extra virgin, virgin, lampante) - is defined by a set of chemical-physical and sensory measurements. The free acidity is the first parameter that has to be determined through a procedure based on an acid-base titration that needs to be carried out in a chemical laboratory.  
This data set contains the in-house validation results of a portable battery-operated electronic system for the determination of free acidity in virgin olive oil that can be used for quick “in situ” tests in a production environment (olive oil mills or packaging centers) by people without particular training.

Content of the file OLEUM_PortableFreeAcidityDetermination_VOO.xlsx/.ods: 
•	tab Calibration contains data used for the calibration of the system carried out analyzing samples of sunflower oil added with different concentration of oleic acid. The samples were analyzed by the official method, to determine the reference value of free acidity, and by the portable system, to measure the conductance value.
•	tab LOD and LOQ contains data used to calculate the limit of detection and quantification of the system.
•	tab Inter-day precision contains data obtained from the analysis of 6 samples (2 for each commercial category) for three different days in order to evaluate the inter-day precision of the system.
•	tab Accuracy contains the values of free acidity measured by the official method and the rapid system on a set of 30 oil samples to evaluate the accuracy of the system.
•	tab Intra-day precision contains the RSD (Relative Standard Deviation) values measured on the set of 30 oils to evaluate the intra-day precision of the system.

File specifics
In the files “,” (comma) has been used as decimal separator.