Simultaneous Determination of Aflatoxin B1 and Ochratoxin A and Natural Occurrence in Mediterranean Virgin Olive Oil

Overview & Synopsis

Olive oil, the most important dietary fat source of Mediterranean diet, can be contaminated by mycotoxins. We investigated an efficient analytical method for simultaneous Aflatoxin B1 (AFB1) and Ochratoxin A (OTA) determination in olive oil. Thirty commercial samples of virgin olive oil, purchased in olive-press plants and supermarket in the southern of Italy and northern Africa, were analysed to verify the analytical procedure and monitor mycotoxin contamination. A simple, rapid and economic method was set up and tested for both the extractive step and the clean-up procedures in simultaneous AFB1 and OTA determination in olive oil. Data obtained showed that OTA was detected with high frequency (80%) in samples from both geographical area (up to 17.0 ng/g) while AFB1 was found from three of four samples of northern Africa (up to 2.4 ng/g). In addition, “not labelled” oil samples proved to be more contaminated by OTA then “labelled” samples (mean value of 2.47 and 0.66 ng/g, respectively). These findings indicate that olive oil can be significantly contaminated by mycotoxins and confirm that a scrupulous application of European Regulation number 1019/2002, that prohibits the sale of not labelled olive oil, is strongly recommended . Final, conventional qualitative parameters such as peroxides number, spectrophotometric evaluation and acid values were not correlated with mycotoxin occurrences.