Comparison and evaluation of the quality of thirty-eight commercial Australian and New Zealand olive oils

Olive oil consumption in Australia has increased dramatically in recent years with the volume of imports increasing from 13,500 tonnes in 1990/91 to 30,000 tonnes in 2000/01. More than 20,000 hectares of olives have been established in Australia and New Zealand since the mid 1990s and some of these are now beginning to bear commercial yields of fruit for oil production from a diverse range of environments. This study has been carried out to determine the range in quality of Australian and New Zealand olive oils and if the quality meets the International Olive Oil Council standards. The results illustrate that the oils selected cover a wide range for each of the quality characteristics tested. Most of the oils were within the IOOC standards for extra virgin olive oil. The fatty acid profiles showed a considerable range with palmitic acid (saturated) levels from 9 to 16% and oleic acid (monounsaturated) from 57 to 84%. Peroxide values were all below 20 meq O₂/kg although some were higher than 15 meq O₂/kg. Free fatty acids were also generally less than 1.0%. Chlorophyll, polyphenol content, UV absorption and induction time were also tested. These results indicate that Australian processing and storage methods, and olive oil quality, are of a high standard.