HS-GC-IMS: A Screening Method Discriminating Quality Grades in Virgin Olive Oils by Specific Volatile Compounds

Enrico Valli, Filippo Panni, Enrico Casadei, Sara Barbieri, Chiara Cevoli, Alessandra Bendini, Fabio Battaglia, Cesare Rossini, Diego L. García González, Tullia Gallina Toschi

University of Bologna; Alma Mater Studiorum - University of Bologna; Alma Mater Studiorum - University of Bologna; DISTAL University of Bologna; DISTAL University of Bologna; DISTAL University of Bologna; LabService Analytica s.r.l; Alma Mater Studiorum - University of Bologna; Instituto de la Grasa (CSIC);DISTAL University of Bologna, Italy

Sensory evaluation, carried out by Panel test, is essential for the quality classification of virgin olive oils (VOOs). The presence and perceived intensity of fruity attribute and sensory defects are linked with the occurrence of specific volatile compounds. Instrumental screening methods based on analysis of volatiles can support the Panel test through fast pre-classification of samples with a known probability, thus increasing the efficiency of quality control.
A Headspace Gas Chromatography Ion Mobility Spectrometer (HS-GC-IMS) was used to analyze 198 commercial VOOs by a semi-targeted approach. PLS-DA models were built by data matrices composed of 15 selected volatiles. The performance (intra-day and inter-day repeatability, linearity) of the method was evaluated with satisfactory results.
Percentages higher than 75% and 73% of correctly classified samples were achieved in cross and external validation, respectively. Quantification of the 15 volatiles highlighted that some of these compounds can be used as headspace key markers to determine VOO quality grades.
The analytical approach presented herein is a promising, relatively easy-to-use and rapid screening tool to support the Panel Test for the discrimination of VOOs according to their quality grade, both for industries and official control laboratories.

This work is developed in the context of the project OLEUM “Advanced solutions for assuring authenticity and quality of olive oil at global scale”, funded by the European Commission within the Horizon 2020 Programme (GA no. 635690). The information expressed in this abstract reflects the authors’ views; the EC is not liable for the information contained therein.