Year 12 | 20 January 2020 | firstname.lastname@example.org
An Australian research shows which are the factors that influence the presence of waxes in the extra virgin olive oils. Then, we discover that the differences can be noteworthy
Which elements are responsible for the solidification of the olive oil at low temperatures? Principally two: the saturated fatty acids and the waxes.
Back at room temperature, the saturated fatty acids melt back immediately while waxes remain solid for some time in suspension in the oil, before depositing at the bottom of the recipient.
The wax content of an oil is a natural and genuine characteristic; some chemical processes can reduce it, though. By the way it is important not to confuse genuinely with quality.
Why are waxes an element of authenticity? In the olive the waxes are deposited on the external part, as a defense against pathogens (e.g. fungi and bacteria) and extreme temperatures. In particular the latter is the element that influences most the olive oil wax content.
Hence, in hot regions the wax content is also three times higher than in cold areas. This is one of the reasons why the oils from the South look more muddy that the others.
This has been confirmed recently by a study by Rod Mailer and coworkers. They compared oils deriving from different areas: two hot areas (SE Queensland and Central Victoria), a fresh area (SW Western Australia) and a cold area (Tasmania). From these samples they confirmed that the wax content can range between 110 ppm in the hot area oils to 40 ppm in the cold area oil.
The genetics is also very important at this regard. They showed that, averaging the different climates, the wax content can range between the 130 mg/kg of the Arbequina variety to the 30 mg/kg of the Coratina variety. As for the Italian varieties, Frantoio is 90 mg/kg, Leccino is 60 mg/kg and Pendolino is 50 mg/kg.
Mailer, R.J., Ayton, J. and Graham K. (2010) The Influence of growing region, cultivar and harvest timing on the diversity of Australian olive oil, J. Am. Oil Chem. Soc. 87:877-884.
by R. T.
01 november 2010, Technical Area > Olive & Oil