Taiwan Food and Drug Administration (TFDA) has discovered target compounds for the identification of virgin olive oils adulterated with refined olive oils by gas chromatography tandem-mass spectrometry (GC-MS/MS). The finding has been published in the journal “Food Additives and Contaminants” in 2017. Using chemical analysis technique to identify the adulterated olive oils is a brand new strategy and this method is useful to protect consumer rights.

Olive oil is a widely used oil in much of the world according to its pleasant taste and aroma. However, the high price of extra virgin olive oils has led to the widespread adulteration of olive oil. The criteria outlined in “Codex standard for olive oils” (CODEX 2015) (e.g. free acidity) make it difficult to discriminate between refined and unrefined olive oils.

The quality of olive oil is generally based on sensory analysis by skilled tasters; however, this method is highly subjective. As a result, TFDA used 3-monochloropropane-1,2-diol (3-MCPD) esters as target compounds to identify extra virgin olive oils adulterated with refined olive oils by GC-MS/MS.

3-MCPD esters form in olive oil at high temperature, and the process of refining olive oil involves heating; therefore, 3-MCPD esters could be used in the grading of olive oil. In 42 commercial olive oil products, the concentrations of 3-MCPD esters were considerably higher in refined oils (olive oil and olive pomace oil) than those in unrefined (extra virgin) olive oils. Furthermore, the distribution of 3-MCPD esters in refined olive oils is widely dispersed.

TFDA shows the outstanding technology after years of development. The authority will use this novel analytical methods to investigate labeling compliance of the commercial extra virgin olive oils in Taiwan market. TFDA continuously develops new analytical methods for food management to protect the public health.