The effect of cultivar and harvest season on the n-alkane and the n-alkene composition of virgin olive oil.

Linear hydrocarbons such as n-alkanes and n-alkenes are contained in the unsaponifable fraction and are one of the less studied class of components in olive oil. This work was conducted in two subsequent harvest seasons (2016–2017 and 2017– 2018) and attentioned the oils of nine olive cultivars: Cassanese, Coratina, Itrana, Leccino, Nociara, Ottobratica, Pendolino, Picholine and Sinopolese grown in the same geographical area (Rizziconi) of the region of Calabria (South Italy). Seven out of the nine cultivars were allochthonous for the geographical area where the experiment was conducted. Height n-alkanes with odd-carbon chain number, seven n-alkanes with even-carbon chain number and three n-alkenes were detected in the following elution order: heneicosane, docosane, tricosene, tricosane, tetracosene, tetracosane, pentacosene, pentacosane, hexacosane, heptacosane, octacosane, nonacosane, triacontane, entriacontane, dotriacontane, tritriacontane, tetratriacontane, pentatriacontane. The cultivar variable produced very high signifcant diferences, this was particularly evident for Sinopolese oil showing a total n-alkanes and n-alkenes content of 260 and 290 mg/kg respectively for the frst and the second harvest season, whereas Ottobratica and Picholine oils contained less than 100 mg/kg and Cassanese and Itrana oils contained less than 50 mg/kg. The highest n-alkene content was found in the oil of Ottobratica 1.97–161 mg/kg, Picholine 2.34–1.99 mg/ kg and in Sinopolese 1.93–2.91 mg/kg. The odd/even ratio was less than 3 for Picholine and Sinopolese and less than 5 for all other cultivars. Docosane was 12.30 and 17.61 mg/kg for Sinopolese and less than 2 mg/kg for all other cultivars. Harvest season did not infuence signifcantly the n-alkanes and n-alkenes content.