1 3 Eur Food Res Technol DOI 10.1007/s00217-016-2660-x ORIGINAL PAPER Use of triacylglycerol profiles established by HPLC–UV and ELSD to predict cultivar and maturity of Tunisian olive oils Marwa Abdallah 1 · María Vergara-Barberán 2 · María Jesús Lerma-García 2 · José Manuel Herrero-Martínez 2 · Mokhtar Zarrouk 1 · Mokhtar Guerfel 1 · Ernesto Francisco Simó-Alfonso 2 Received: 5 October 2015 / Revised: 4 February 2016 / Accepted: 13 February 2016 © Springer-Verlag Berlin Heidelberg 2016 Abbreviations ACN Acetonitrile ELSD Evaporative light scattering detector HPLC High-performance liquid chromatography EVOO Extra virgin olive oil LDA Linear discriminant analysis MS Mass spectrometry PN Partition number TAG Triacylglycerol Introduction Extra virgin olive oil (EVOO) is the principal source of fat in the Mediterranean diet with high nutritional value and significant health benefits. It is the only vegetable oil that can be consumed directly in its raw state, by cold-pressing of olive fruit, using exclusively mechanical procedures without any further treatments or chemical additions [1]. Olive oil plays an important role in the Tunisian agron- omy and economy. Olive trees, which cover an area of 1.611200 ha spread from north to south, accounting for more than 4 % of the olive oil world production [2]. The most cultivated Tunisian varieties are Chétoui and Chem- lali [1, 3–5], although Tunisia has a great genetic diversity among its olive trees. The quality of olive oil is influenced by a great number of factors such as geographical location [6, 7], agronomic practices [8], extraction process [9], irrigation [1, 3], har- vest time [10], crop season [11, 12] and climatic conditions [13]. It has been suggested that cultivar [1, 3, 5, 6, 12, 14– 21] and the olive maturity stage (degree of ripening) [1, 3– 5, 10–12, 14, 15, 18, 19, 21–24] are two of the most impor- tant ones. When olive maturation proceeds, a number of changes occur in the fruit (weight, pulp-stone ratio, colour Abstract The usefulness of triacylglycerol (TAG) pro- files established by high-performance liquid chromatogra- phy using both UV and evaporative light scattering (ELSD) detectors as a tool to discriminate between seven cultivars of Tunisian extra virgin olive oils (EVOOs) was evaluated in this work. Moreover, the discrimination of EVOOs from the cultivars Chemchali, Fouji and Zarrazi, characterized with different maturity indexes, was also studied. With both detectors, a total of 19 peaks, which were common to all the EVOOs studied, were observed. However, ELSD peaks, which provided a higher signal-to-noise ratio than the UV peaks, were selected to construct linear discriminant anal- ysis models for cultivar and maturity index prediction. In all cases, an excellent resolution between all category pairs was achieved, which demonstrated that TAG profiles are a good marker of both cultivar and maturity index of EVOOs. Keywords Olive cultivar · HPLC · Linear discriminant analysis · Maturity index · Triacylglycerols · Tunisian extra virgin olive oils Marwa Abdallah and María Vergara-Barberán have contributed equally to this work, and they should be considered co-first authors. Electronic supplementary material The online version of this article (doi:10.1007/s00217-016-2660-x) contains supplementary material, which is available to authorized users. * María Jesús Lerma-García m.jesus.lerma@uv.es 1 Laboratoire Biotechnologie de l’Olivier, Faculté des sciences de Tunis, Centre de Biotechnologie de Borj Cedria, Univesité de Tunis El Manar, BP 901, 2050 Hammam-Lif, Tunisia 2 Department of Analytical Chemistry, University of Valencia, C. Doctor Moliner 50, 46100 Burjassot, Valencia, Spain