New OLEUM publication in the MDPI Journal Foods

The category of virgin olive oil is currently assigned on the basis of chemical-physical and sensory parameters following official methods. Considering the limited number of samples that can be analysed daily by a sensory panel, an instrumental screening tool could be supportive by reducing the assessors’ workload and improving their performance. The approach is based on the volatile fraction fingerprint obtained by HS-SPME–GC–MS from more than 300 virgin olive oils from two crop seasons. Performing the screening approach, only the virgin olive oils classified as uncertain would be assessed by a sensory panel, while the rest would be directly classified into a given commercial category. The sensory panel’s workload would be reduced to less than one-third of the samples.

Quintanilla-Casas, B., Marin, M., Guardiola, F., García-González, D.L., Barbieri, S., Bendini, A., Gallina Toschi, T., Vichi, S., Tres, A. Supporting the Sensory Panel to Grade Virgin Olive Oils: An In-House-Validated Screening Tool by Volatile Fingerprinting and Chemometrics. Foods, 9(10), p. 1509.

New OLEUM publication in the MDPI Journal Foods

Sensory evaluation, carried out by panel tests, is essential for the quality classification of virgin olive oils (VOOs). Unfortunately, this process is both time-consuming and costly when many samples need to be assessed. There is a need to investigate whether sensory evaluation could be assisted by the application of alternative screening methods. In this paper, a rapid instrumental method based on the analysis of volatile molecules was consider to help assist the panel test through a fast pre-classification of samples with a known level of probability. A headspace gas chromatography-ion mobility spectrometer (HS-GC-IMS) was used to analyze 198 commercial VOOs (extra virgin, virgin and lampante) by a semi-targeted approach. The performance of this method was evaluated for its potential to support panel tests.

Valli, E., Panni, F., Casadei, E., Barbieri, S., Cevoli, C., Bendini, A., García-González, D.L. and Gallina Toschi, T., 2020. An HS-GC‐IMS Method for the Quality Classification of Virgin Olive Oils as Screening Support for the Panel Test. Foods, 9(5), p.657.

New OLEUM publication in the MDPI Journal Foods

The sensory methodology for virgin olive oils (VOOs) known as the “panel test” represents the most valuable approach to assess sensory characteristics and quality for consumer and producer protection. This paper highlights the possibilities for amelioration panel tests and describes the proficiency improvement given by formative training, and the method used to obtain sensory classified samples from analysis of a set of VOOs to be used for calibration of rapid instrumental screening methods.

Barbieri, S., Brkić Bubola, K., Bendini, A., Bučar-Miklavčič, M., Lacoste, F., Tibet, U., Winkelmann, O., García-González, D.L. and Gallina Toschi, T., 2020. Alignment and Proficiency of Virgin Olive Oil Sensory Panels: The OLEUM Approach. Foods, 9(3), p.355.

New OLEUM publication in the Journal Food Chemistry

The commercialization of declared blends of olive oil and seed oil is something long approved by the European Union. For olive oil, the percentage must be at least 50% if the producer aims to advertise its presence on the front label. However, there is currently no designated method to verify such proportion. In this article, OLEUM researchers purpose the use of decisional trees based on the greatest differences between olive and seed oils for a variety of parameters including triacylglycerols, acyclic saturated hydrocarbons, free sterols, and tocopherols.

Gómez-Coca, R.B., del Carmen Pérez-Camino, M., Martínez-Rivas, J.M., Bendini, A., Toschi, T.G. and Moreda, W., 2020. Olive oil mixtures. Part one: Decisional trees or how to verify the olive oil percentage in declared blends. Food Chemistry, 315, p.126235.

New OLEUM publication in LWT - Food Science and Technology

Sensory quality, assessed following a standardized method, is one of the parameters defining the commercial category of virgin olive oil. Considering the difficulties linked to the organoleptic evaluation, especially the high number of samples to be assessed, setting up instrumental methods to support sensory panels becomes a need for the olive oil sector. This paper explored the use of volatile fingerprinting by Headspace Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry as a tool to evaluate the volatile fraction responsible for virgin olive oil sensory attributes. 

Quintanilla-Casas, B., Bustamante, J., Guardiola, F., García-González, D.L., Barbieri, S., Bendini, A., Toschi, T.G., Vichi, S. and Tres, A., 2019. Virgin olive oil volatile fingerprint and chemometrics: Towards an instrumental screening tool to grade the sensory quality. LWT, p.108936.

New OLEUM publication in the Journal Food Chemistry

The verification of the geographical origin of extra virgin (EVOO) and virgin olive oil (VOO) is crucial to protect consumers from misleading information. Despite the large number of studies performed, specific markers are still not available. The present study aims to evaluate sesquiterpene hydrocarbons (SHs) as markers of EVOO geographical origin and to compare the discrimination efficiency of targeted profiling and fingerprinting approaches.

Profiling versus fingerprinting analysis of sesquiterpene hydrocarbons for the geographical authentication of extra virgin olive oils

New OLEUM publication in Food Control

In this paper a portable battery-operated electronic system to measure olive oil free acidity is presented: the system can be used for quick “in situ” tests in a production environment (olive oil mills or packaging centers) by people without particular training. The working principle of the system is based on the creation of an emulsion between oil and a hydroalcoholic solution: the free acidity is estimated on the value of the emulsion electrical conductance.

Design and in-house validation of a portable system for the determination of free acidity in virgin olive oil

New OLEUM publication in Molecules

OLEUM researchers have published a new research article.

Tsimidou, M.Z., Sotiroglou, M., Mastralexi, A., Nenadis, N., García-González, D.L. and Gallina Toschi, T., 2019. In House Validated UHPLC Protocol for the Determination of the Total Hydroxytyrosol and Tyrosol Content in Virgin Olive Oil Fit for the Purpose of the Health Claim Introduced by the EC Regulation 432/2012 for “Olive Oil Polyphenols”. Molecules, 24(6), p.1044.

In this video, Dr Nikolaos Nenadis from Aristotle University of Thessaloniki goes through the validation protocol to determine total hydroxytyrosol and tyrosol content in olive oil. This method is fit for the purpose of regulating the EU health claim for olive oil polyphenols (EC REGULATION 432/2012).

Download the slide here

New OLEUM publication in Molecules

OLEUM researchers have published a new scientific paper

This article discusses the pros of a recently published in house validated ultra high performance liquid chromatography (UHPLC) protocol compared with those of other procedures that determine directly or indirectly the compounds hosted under the health claim on “olive oil polyphenols” (EC regulation 432/2012).

Tsimidou, M Z., Nenadis, N., Mastralexi, A., Servili, M., Butinar, B., Vichi, S., Winkelmann, O., García-González, D L., Toschi, TG., 2019. Toward a Harmonized and Standardized Protocol for the Determination of Total Hydroxytyrosol and Tyrosol Content in Virgin Olive Oil (VOO). The Pros of a Fit for the Purpose Ultra High Performance Liquid Chromatography (UHPLC) Procedure. Molecules, 24(13), p.2429.

New OLEUM publication in Trends in Food Science and Technology

OLEUM researchers have published a new scientific paper.

The review identifies the current gaps in EU legislation and discusses the drawbacks of the existing analytical methods used with respect to olive oil. It also provides some suggestions for the replacement of specific steps within the present EU methods with more efficient analytical solutions to reduce time and/or solvent consumption.

Conte, L., Bendini, A., Valli, E., Lucci, P., Moret, S., Maquet, A., Lacoste, F., Brereton, P., García-González, D.L., Moreda, W. and Toschi, T.G., 2019. Olive oil quality and authenticity: a review of current EU legislation, standards, relevant methods of analyses, their drawbacks and recommendations for the future. Trends in Food Science & Technology  


New OLEUM publication in the European Journal of Lipid Science and Technology

OLEUM researchers have published a new scientific paper. 

The determination of the total hydroxytyrosol and tyrosol content of virgin olive oil is of utmost interest for the International Olive Council (IOC), food authorities, producers and distributors after the issuing of a health claim that ‘olive oil polyphenols contribute to the protection of blood lipids from oxidative stress’. This study focused on developing a more harmonized and standardized methodology for the extraction and analysis of hydroxytyrosol (Htyr) and tyrosol (Tyr). 

Nenadis, N., Mastralexi, A., Tsimidou, M.Z., Vichi, S., Quintanilla‐Casas, B., Donarski, J., Bailey‐Horne, V., Butinar, B., Miklavčič, M., García González, D.L. and Gallina Toschi, T., 2018. Toward a harmonized and standardized protocol for the determination of total hydroxytyrosol and tyrosol content in virgin olive oil (VOO). Extraction solvent. European Journal of Lipid Science and Technology, 120(11), p.1800099. 

New OLEUM publication in the European Journal of Lipid Science and Technology

OLEUM researchers have published a new scientific paper. 

The viewpoint is the outcome of the scientific expertise of the scientists that sign it and work collaboratively in the frame of the OLEUM project. The consensus among scientists, the European food authorities, IOC, and the olive industry on which compounds should be determined to support the health claim on olive oil polyphenols (EC Reg. 432/2012) is of utmost importance and can be supported by the evidence provided in this viewpoint article.

Tsimidou M. Z., Nenadis N., Servili M., García-Gonzáles D. L., Gallina Toschi T. 2018. Why tyrosol derivatives have to be quantified in the calculation of “olive oil polyphenols” content to support the health claim provisioned in the EC Reg. 432/2012. European Journal of Lipid Science and Technology, DOI: 10.1002/ejlt.201800098.

New OLEUM publication in Agro Food Industry Hi-Tech

OLEUM researchers have published a new paper in Agro Food Industry Hi Tech. The article introduces the European Union Horizon 2020 funded project OLEUM which aims to better guarantee olive oil quality and authenticity through improved methods for detecting and preventing olive oil fraud.

Gallina Toschi T., Valli E., Conte L., García-Gonzáles D. L., Maquet A., Brereton P., Mcgrath N., Celemín L.F., Bendini A. EU project OLEUM: Better solutions to protect olive oil quality and authenticity, Agro Food Industry Hi-Tech, 28 (5), 2-3 (2017).

List of existing databases on olives and olive oils

One objective of the OLEUM project is to establish an open access databank to store not only the information generated by the OLEUM consortium but also to be interoperable with already existing databases related to the characterisation of the olive tree germplasm and olive oils.

This report specifically summarises information on existing databases related to Olea europaea mainly curated in Europe but also in other part of the world. Information was gathered via the partners of the OLEUM consortium as well as available publications and internet consultations.

A total of 15 databases have been identified, of which 10 are web-based and currently accessible. However, an accessible database does not mean that necessarily the available information can be partially or entirely re-used in another database; reason why it is essential to contact each curator as a second step.

In order to identify an unknown monovarietal virgin olive oil cultivar, several reference databases have been established providing morphologic, DNA molecular markers and/or chemical data of worldwide olive trees and oils. The olive cultivar identification and olive oil authentication are especially important for protection of certified brands such as Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI).

Apparently, there is no database centralising the passport data of all the olive accessions distributed in the existing germplasm banks of olive. However, considering the information gathered, it seems that a significant percentage of the olive germplasm is conserved in the European germplasm banks; the two most important ones being the Worldwide Olive Germplasm bank of Cordoba and the CRAOLI collection, for which elaiographic cards are also available. These cards include morphological and agronomical data as well as a variety of molecular and chemical descriptors. A huge amount of work has been carried out in the past two decades to characterise cultivars by molecular markers, however results are disseminated in several databases or scientific publications.

Several databases are storing data on chemical composition of olive oils from conventional chemical analyses; e.g. fatty acids, triglycerides, organoleptic oil values. Only one database (i.e. Italian National Database of PDO/PGI Extra Virgin Olive Oils) is maintaining data from isotopic measurements as well as from a metabolomics approach.

By sharing or even integrating olive databases in the sense of the data FAIR principles recommended by the Horizon 2020 framework, it is expected to provide proper references to data, to allow them to be reused, to increase their reproducibility and to promote collaborations. Several technical platforms, portals and tools currently available for achieving such data management are discussed in the deliverable. Further tasks are also described for collaborating and exchanging data with curators of identified databases and to explore not yet listed databases.

Click here to read the full report.

Developing the OLEUM visual identity and website

This report summarises the development of the project’s visual identity and graphic charter, including the logo and communication templates. These will ensure a common
graphic/visual line to be easily recognised among external stakeholders. It also describes the development of the OLEUM website. The public facing website will be a portal for dissemination information about the project to a wide range of audiences.

Click here to read the full report.

Protocol for the production and homogeneity assessment of olive oil test materials

During the OLEUM project, different partners will be carrying out analysis of various blends of extra virgin olive oils (EVOOs) with soft-deodorised olive oils (sdOOs) and blends of EVOOs or olive oils (OOs) with other vegetable oils. Interlaboratory comparisons of the results will establish the extent to which different laboratories can detect the same adulterations by applying the same methods.

A successful interlaboratory comparison depends on the production of the test materials, namely the exchanged samples. Test material production and characterisation (homogeneity testing) will rely on the established experience of Fera’s proficiency testing group, who routinely carry out interlaboratory tests for food quality parameters.

This document is a protocol for the production and homogeneity assessment of test materials as oils blended at different proportions.

To read the full report, click here.