Geographical origin discrimination of "Ntopia" olive oil cultivar from Ionian islands using volatile compounds analysis and computational statistics

Effimia Eriotou; Ioannis K Karabagias; Sofia Maina; Dionysios Koulougliotis; Nikolaos Kopsahelis

doi:10.1007/s00217-021-03863-2

Geographical origin discrimination of "Ntopia" olive oil cultivar from Ionian islands using volatile compounds analysis and computational statistics

Eur Food Res Technol. 2021;247(12):3083-3098. doi: 10.1007/s00217-021-03863-2. Epub 2021 Sep 20.

Authors

Effimia Eriotou¹, Ioannis K Karabagias^{2

3}, Sofia Maina^{1

4}, Dionysios Koulougliotis⁵, Nikolaos Kopsahelis¹

Affiliations

¹ Department of Food Science and Technology, Ionian University, 28100 Argostoli, Kefalonia Greece.
² Laboratory of Food Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece.
³ Department of Food Science and Technology, School of Agricultural Sciences, University of Patras, Charilaou Trikoupi 2, 30100 Agrinio, Greece.
⁴ Department of Food Science and Human Nutrition, Agricultural University of Athens, Iera Odos 75, 11855 Athens, Greece.
⁵ Department of Environment, Ionian University, M. Minotou-Giannopoulou, 29100 Zakynthos, Greece.

Abstract

The aim of the present study was to characterize the aroma profile of olive oil of the "Ntopia" (local) cultivar from the Ionian islands (Zakynthos, Kefalonia, Leukada, and Kerkyra) (Greece), and investigate whether specific volatile compounds could be considered as indicators of olive oil geographical origin, using computational statistics. In this context, 137 olive oil samples were subjected to headspace solid phase microextraction coupled to gas chromatography/mass spectrometry using the internal standard method. Computational statistics on the semi-quantitative data of olive oil samples, as rapid machine learning algorithms, showed that specific volatile compounds could be used as indicators of geographical origin of olive oil of the "Ntopia" cultivar, among the four main Ionian islands. Volatile compounds such as ethanol, pentanal, 2,4-dimethylheptane, 3,7-dimethyl-1,3,6-octatriene (E), 2,5-dimethylnonane, 1-hexanol, 6-methyl-5-hepten-2-one, octanal, dl-Limonene, acetic acid hexyl ester and dodecane could aid to the geographical origin discrimination of "Ntopia" olive oil cultivar when two (Zakynthos and Kefalonia) or four (Zakynthos, Kefalonia, Leukada and Kerkyra) Ionian islands are subjected to statistical analysis. The discrimination rate using the cross-validation method was 100% and 85.7%, respectively. These results were further evaluated using training and holdout partitions, during which a comparable classification rate was obtained.

Supplementary information: The online version contains supplementary material available at 10.1007/s00217-021-03863-2.

Keywords: Characterization; Computational statistics; Geographical origin; Olive oil; Volatile compounds; “Ntopia” cv..