Volatile compounds in virgin olive oil: occurrence and their relationship with the quality

Abstract

The stimulation of the human sensory receptors by volatile compounds present in virgin olive oils gives rise to the sensory attributes that describe its delicate and fragrant aroma. The composition of the volatile compounds and their biogenesis is briefly illustrated. Analytical methodologies for evaluating the volatile fraction and the sensory properties of virgin olive oils are elucidated. Compounds responsible for typical flavours are examined and the influence of the main factors on the composition of volatile compounds is discussed. The origin of off-flavours are also described and the consequent changes of volatile composition and of sensory characteristics are analysed. The relationships between volatile compounds and sensory attributes are discussed.

Volatile compounds of Algerian extra-virgin olive oils: Effects of cultivar and ripening stage

“…The latter stage corresponded to a fruit with a black skin and a white flesh. Our findings are different from those published by other researches, whereby the maximum concentration of C6 volatiles occurred at a time when the fruit's skin color turned from yellow-green to purple [5] ; after this period, the amount of volatiles was inversely proportional to the degree of ripening due to the lower activity of enzymes involved in the production of this class of compounds [5] and/or poor availability of the substrates. [43] Additional studies will be required to confirm these hypotheses.…”

“…It is well known that (E)-2-hexenal is produced by the enalisomerase which catalyzes the isomerization of (Z)-3-hexenal to the more stable (E)-2 form. [5] Further investigations are needed to confirm this hypotheses. The other C6 aldehyde identified was hexanal (0.23-3.88 mg/L) ( Table 2).…”

“…[3,4] Many of these compounds are produced enzymatically by the so-called lipoxygenase (LOX) pathway, occurring in the disrupted cell structure during olive oil production, from free polyunsaturated fatty acids, particularly linoleic and α-linolenic acids. [3,5] More specifically, both C6 aldehydes, alcohols, and their corresponding esters, and minor amounts of C5 carbonyl compounds, alcohols, and pentene dimers are responsible for the positive odors and pleasant notes in olive oils. On the other hand, other volatile compounds have been reported to be responsible for the unpleasant aroma and odors resulting from olive oil; these compounds can be derived from different mechanisms such as: sugar fermentation, amino acid conversion, enzymatic activities of molds or anaerobic microorganisms, and other auto-oxidative processes.…”

“…[7,8] The cultivar is one of the main factors that can determine the content and profile of VOO volatile compounds. [5,8] Its effect was evidenced by the presence of different amounts of C6 compounds arising from oils produced under the same operating conditions of the extraction process of different fruit cultivars harvested at the same ripening stage. [9,10] It has been presumed that enzyme levels and enzyme's activity, involved in the biogenesis of volatiles, are genetically determined in each olive cultivar.…”

Flash Thermal Conditioning of Olive Pastes during the Oil Mechanical Extraction Process: Cultivar Impact on the Phenolic and Volatile Composition of Virgin Olive Oil

“…The heat exchanger was placed in front of a traditional, covered malaxer to rapidly thermally condition the olive paste and improve the concentration of the volatile fraction, with a consequent optimal effect on the VOO organoleptic notes. As reported by other authors, 10,12,17,23 this study also suggests how the optimization of the best operative conditions during the traditional and/or innovative malaxing process could depend on the genetic origin of the olives.…”