3.1.3. Aldehydes

Among unsaturated aldehydes formed in the so-called LOX pathway, Buža, followed by Rosinjola and Oblica EVOOs, contained the highest concentrations of (*E*)- and (*Z*)-3-hexenal, respectively (Table 1). The same monovarietal EVOOs, with sporadic exceptions, were also distinguished by high levels of pentenals, hexadienals, and (*E*)-2-octenal. Oblica EVOO had high concentration of decadienals. Leccino was clearly distinguished from the other monovarietal EVOOs by the highest level of the major EVOO volatile, (*E*)-2-hexenal, as well as that of (*E*,*E*)-2,4-heptadienal. Leccino EVOO had the lowest concentration of (*Z*)-3-hexenal, although not statistically different from that found in I. bjelica and Lastovka EVOOs. Lastovka EVOO was characterized by rather low levels of particular LOX-derived hexenals, as well as pentenals, octanal, and hexadienals. Istarska bjelica contained low concentrations of (*Z*)-3-hexenal and decadienals. Among saturated aldehydes originating from the processes other than LOX, 3-methylbutanal turned out to be an exclusive marker of I. bjelica, while abundance in 2-methyl-2-pentenal was observed in Rosinjola EVOO (Table 1). Higher levels of hexanal clearly discriminated Dalmatian (Oblica and Lastovka) from Istrian monovarietal EVOOs.


**Table 1.** Concentrations (µg/kg unless otherwise stated) of volatile aroma compounds determined by gas chromatography-ion trap mass spectrometry (GC-IT-MS)after headspace solid-phase microextraction (HS-SPME) from monovarietal extra virgin olive oils produced from Buža, Istarska bjelica, Rosinjola, Oblica, Lastovka,and Leccino varieties in Croatia.


*Foods***2019**, *8*, 565












*Foods***2019**, *8*, 565



*Foods***2019**, *8*, 565



semi-quantitatively

letters in a row represent

 and their

 statistically

 significant

 differences

 between mean values at *p* < 0.05 obtained by one-way ANOVA and least significant

concentrations

 were expressed

 as equivalents

 of compounds

 with similar chemical structure

 assuming

 a response factor = 1. Different superscript

 difference

 (LSD) test.

 lowercase
