Influence of harvest year and cultivar on wax composition of olive oils

Olive oils extracted from Italian cultivars grown in the Region of Calabria, Southern Italy were analyzed for their wax ester composition, for three successive harvest years. Three autochthonous cultivars from Calabria: Cassanese, Ottobratica, and Sinopolese and seven allochtonous cultivars: Coratina, Itrana, Leccino, Nocellara Messinese, Nociara, Pendolino, and Picholine were considered. This work demonstrates the presence of significant differences (ANOVA) for the different wax ester compounds present in these olive oils, taking into consideration the cultivar and the harvest year. The studied olive oils present a good wax ester composition according to both EU and IOC regulations. The cultivar Ottobratica showed the highest wax ester content, whereas Itrana presented the lowest content. Practical applications: Wax esters are naturally present on the drupe cuticle and are transferred into olive oil by means of mechanical extraction and especially by solvent extraction on an industrial scale. They are a legal parameter contained in the European Union regulation and in the International Olive Oil Council regulation. Wax esters are a quality indicator for olive oil evaluation, especially to detect a fraudulent admixture of pomace olive oil in labeled extra virgin olive oil or in labeled monocultivar extra virgin olive oil. The adaptability of allochthonous cultivars in a different geographical area is also demonstrated.