ToF-SIMS and PCA studies of Seggianese olives and olive oil

In recent years the characterization of agricultural and food products has focused on nutritional properties. However, additives and contaminants may not only be transferred to plants and fruits, but they can also induce alterations and compromise the overall quality. In this context, chemical fingerprint analysis is a valuable tool for complementing more conventional analytical methods. We used time of flight secondary ion mass spectrometry (ToF-SIMS) to characterise three different groups of Seggianese olives: (i) treated with an insecticide (dimethoate) and a fungicide (copper oxychloride) (TU); (ii) untreated (UT); and (iii) treated-washed (TW). Intact olive slices and olive oil were analyzed. Principal component analysis (PCA) of the Tof-SIMS spectra was used to investigate similarities among samples. Results showed that TW olives were more similar to UT samples than to TU samples. However, the washing process was not totally effective, since the treatment was able to induce alterations in the composition of the olives.