Evaluation by an electronic nose of olive oil oxidation during storage

An electronic nose based on an array of 12 Metal Oxide Semiconductor (MOS) sensors and 10 Metal Oxide Semiconductor Field–Effect Transistor (MOSFET) sensors was investigated to determine if it could be used to monitor olive oil oxidation during storage. Samples of extra virgin olive oil, olive oil and olive-pomace oil were stored at 40°C in the dark for 64 days. At established times, the three types of olive oil were evaluated for volatile compounds by the electronic nose and for peroxide value. The electronic nose data and the peroxide values were correlated and, on the basis of the correlation coefficients, a small number of sensors were selected. The responses of the selected sensors were analysed by Principal Component Analysis. The first principal component was able to discriminate olive oil samples on the basis of aging time. These results suggest that the electronic nose may be suitable for measuring changes in volatile compounds associated with olive oil oxidation during storage.