title: Combined untargeted and targeted fingerprinting with comprehensive two-dimensional chromatography for volatiles and ripening indicators in olive oil.
abstract: Comprehensive two-dimensional gas chromatography (GC × GC) is the most effective multidimensional separation technique for in-depth investigations of complex samples of volatiles (VOC) in food. However, each analytical run produces dense, multi-dimensional data, so elaboration and interpretation of chemical information is challenging. This study exploits recent advances of GC × GC-MS chromatographic fingerprinting to study VOCs distributions from Extra Virgin Olive Oil (EVOO) samples of a single botanical origin (Picual), cultivated in well-defined plots in Granada (Spain), and harvested at different maturation stages. A new integrated work-flow, fully supported by dedicated and automated software tools, combines untargeted and targeted (UT) approaches based on peak-region features to achieve the most inclusive fingerprinting. Combined results from untargeted and targeted methods are consistent, reliable, and informative on discriminant features (analytes) correlated with optimal ripening of olive fruits and sensory quality of EVOOs. The great flexibility of the UT fingerprinting here adopted enables retrospective analysis with great confidence and provides data to validate the transferability of ripening indicators ((Z)-3-hexenal, (Z)-2-hexenal, (E)-2-pentenal, nonanal, 6-methyl-5-hepten-2-one, octane) to external samples sets. Direct image comparison, based on visual features, also is investigated for quick and effective pair-wise investigations. Its implementation with reliable metadata generated by UT fingerprinting confirms the maturity of 2D data elaboration tools and makes advanced image processing a real perspective.
authors: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Turin, Italy.
authors: Federico
authors: F
authors: Magagna
authors: Department Analytical Chemistry, Faculty of Science, University of Granada, C/Fuentenueva s/n, 18071, Granada, Spain.
authors: Lucia
authors: L
authors: Valverde-Som
authors: Department Analytical Chemistry, Faculty of Science, University of Granada, C/Fuentenueva s/n, 18071, Granada, Spain.
authors: Cristina
authors: C
authors: Ruíz-Samblás
authors: Department Analytical Chemistry, Faculty of Science, University of Granada, C/Fuentenueva s/n, 18071, Granada, Spain.
authors: Luis
authors: L
authors: Cuadros-Rodríguez
authors: University of Nebraska - Lincoln, Lincoln, NE 68588-0115, USA.
authors: Stephen E
authors: SE
authors: Reichenbach
authors: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Turin, Italy.
authors: Carlo
authors: C
authors: Bicchi
authors: Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Turin, Italy. Electronic address: chiara.cordero@unito.it.
authors: Chiara
authors: C
authors: Cordero
mesh_terms: D002849:Chromatography, Gas; D008401:Gas Chromatography-Mass Spectrometry; D000069463:Olive Oil / Q000737:chemistry*; D052617:Solid Phase Microextraction; D055549:Volatile Organic Compounds / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D000069463:Olive Oil; D055549:Volatile Organic Compounds
keywords: Comprehensive two-dimensional gas chromatography-mass spectrometry; Extra Virgin Olive Oil; Olives ripening; Retrospective investigations; Untargeted and targeted fingerprinting