Natural Variation of Volatile Compounds in Virgin Olive Oil Analyzed by HS-SPME/GC-MS-FID

Abstract

Virgin olive oil is unique among plant oils for its high levels of oleic acid, and the presence of a wide range of minor components, which are responsible for both its health-promoting properties and characteristic aroma, and only produced when olives are crushed during the industrial process used for oil production. The genetic variability of the major volatile compounds comprising the oil aroma was studied in a representative sample of olive cultivars from the World Olive Germplasm Collection (IFAPA, Cordoba, Spain), by means of the headspace solid-phase microextraction/gas chromatography-mass spectrometry-flame ionization detection (HS-SPME/GC-MS-FID). The analytical data demonstrated that a high variability is found for the content of volatile compounds in olive species, and that most of the volatile compounds found in the oils were synthesized by the enzymes included in the so-called lipoxygenase pathway. Multivariate analysis allowed the identification of cultivars that are particularly interesting, in terms of volatile composition and presumed organoleptic quality, which can be used both to identify old olive cultivars that give rise to oils with a high organoleptic quality, and in parent selection for olive breeding programs.

Genetic and Environmental Effect on Volatile Composition of Extra Virgin Olive Oil

“…[27--29] Moreover, similar results regarding the importance and variability of this compound have been previously described in EVOO. [27,30,29] (E)+(Z)-hex-3-enal, were the second most important contributors to EVOO's aroma of C6/LnA, also having an AOV>1 in 74.5% of the samples analyzed.…”

“…The most abundant compounds were those derived from LnA, such as C6/LnA and C5/LnA (14 118 and 13 909 µg /kg −1 , respectively), which was observed in previous studies carried out on large collections of olive cultivars. [27][28][29] However, among all compounds detected, only few of them were found in quantities above its odor threshold (OAV > 1), so a low number of compounds could be considered to have a highlighted contribution to EVOOs' aroma.…”

“…Similar contents of C5/LnA compounds were previously described for different olive cultivars and progenies. [27,28,30] C5/LA compounds (group G4) were identified, such as pentan-3-one and pentanal, but none of them was detected over its odor threshold (Table 1). Pentan-3-one was described in similar quantities in different EVOOs from several cultivars.…”

“…Similarly, (E)‐hex‐2‐enal was the main compound contributing to the aroma of EVOOs from different cultivars representing a wide genetic diversity of the Word Olive Germplasm Bank of IFAPA (Córdoba). [ 27–29 ] Volatile compounds in sets of 36, 39, and 61 olive cultivars were previously studied, and most of the cultivars were characterized by high (E)‐hex‐2‐enal content reaching the odor threshold in 100% of the EVOO samples. [ 27 –‐ 29 ] Moreover, similar results regarding the importance and variability of this compound have been previously described in EVOO.…”

“…[9,11,13,25] The variability in volatile composition due to genetic influence has been characterized in a wide number of cultivars including local cultivar grown in specific regions [21,26] or representative cultivars from all over the world growing in cultivar collections. [27][28][29] Moreover, a high variability, even transgressing the genitors, has been found among progenies of breeding programs, [30] which showed the potential to develop new cultivars with different EVOOs composition. Therefore, olive breeding programs include minor compounds among its breeding objectives together with many other important agronomic traits, such as high productivity, disease resistance, and suitability to different growing systems.…”