Various studies around the world have shown that the volatile compounds in olive oils, depend on the climate, cultivation and process.
The term “volatile compound” is used differently in various places. The US environmental legislation, defines the volatile compounds, depending on their reactivity. The European legislation defines the volatile compounds, depending on their evaporation into the atmosphere.
The olive oil’s aromas are determined by a mixture of chemicals in olive oil, that influence its quality. The quantity of volatiles and aromas depends on synergistic and antagonistic effects. The exogenous volatile compounds, like solvent residues and aromatic hydrocarbons found in olive oils, depend on the type of extraction. The volatile compounds and especially hydrocarbons in extra virgin olive oil, are present naturally or because of contamination due to absorption by packaging materials.
The difference between oils around the world are complicated by factors such as climate, harvesting time, process and a number of other reasons, that influence the content of the volatile compounds. Because these factors vary geographically, the volatile compounds in olive oil also vary.
Studies in Spain and Italy show that the levels of volatile compounds decrease substantially during the course of the ripening of the olives, but they are higher on irrigated olive oil. Wine gets better by aging, but olive oil is better when it is fresh. Age effects the quality and storage brings rancidity.
Most extra virgin olive oils contain similar volatile compounds at various concentrations. The different flavors of olive oils can be attributed to different concentrations of the presence or absence of the potent odor components.
The most common and important volatile compounds in European extra virgin olive oils are the hexan-1-ol, hexanal and 3-methylbutan-1-ol. In Australian extra virgin olive oils are the damascenone and aldehyde.
A study of Italian and Moroccan extra virgin olive oil showed c6 volatile compounds in Italian olive oils. The Moroccan olive oils were abundant in fruity esters. The Australian olive oils contained hexyl acetate and ethyl isobutyrate with a rare presence of esters.
The consumption of extra virgin olive oil in Greece, Italy, Spain and Australia, demonstrates that the Mediterranean countries are the highest consumers of olive oil in comparison with Australia. In Greece the consumption of olive oil is significantly high. The excessive consumption of olive oil though is not toxically risky in respect of consumption of volatile compounds.