AUTHENTICITY AND QUALITY OF EXTRA VIRGIN OLIVE OIL: FUTURE DIRECTIONS FOR ANALYTICAL TECHNIQUES

The International Olive Council (IOC) has developed a classification system which defines nine classes of olive oil ranging from extra virgin to pomace oil. Despite this, the value and importance of olive oil has led to wide scale corruption and fraud. Refined, adulterated or poor quality oil, labeled as extra virgin olive oil, has been found on supermarket shelves in significant quantities. Numerous sophisticated tests have been developed for olive oil to prove its authenticity and its quality. Poor storage and handling are perhaps the main contributors to low quality olive oil being sold to consumers. There are virtually no internationally accepted analytical methods to identify freshness and deteriorated products. Research studies by the Australian Oils Research Laboratory (AORL) and research organizations in the USA have compared sensory analysis with chemical tests and illustrated the limitations of many of those tests to define characteristics necessary to meet the IOC definition of “extra virgin”. Additionally new tests, 1,2-di-acylglycerol and pyropheophytin a, developed by the German Society for Fat Science (DGF) have been evaluated at the AORL and been shown to clearly identify oil that is old, has been stored incorrectly or has been heated, as in refining. Elevated temperature caused rapid reduction in proportions of 1,2-di-acylglycerol and increases in pyropheophytin a. These two parameters were also shown to change over time and/or with the exposure to oxygen. Storage in inappropriate containers also resulted in changes in the proportions of these components.