In this study we have investigated the applicability of a commercial e-nose in the monitoring of the quality of a ready to use fresh cut fruit (packaged pineapple slices) with a short shelf life. The pineapple trays were taken at the beginning of their commercial life and stored at three different temperatures (5.3, 8.6 and 15.8 degrees C) for 6-10 days in order to apply two analytical approaches: 1) a classical monitoring by means of a series of sensoristic analysis on samples taken at various stages of storage; 2) a continuous method with the e-nose probe directly in contact with the headspace of the pineapple. The results showed that the e-nose was able to discriminate between several samples and to correlate the changes in volatile compounds to a quality decay due to different time-temperature storage conditions. In particular, for each storage temperature, a transition function was applied in order to interpolate the PC1 score trend versus the storage time. The second derivative of the transition function was calculated to estimate the stability time. Results revealed that freshness of fruit was maintained for about 5 days at 5 degrees C, 3 days at 9 degrees C and 1 day at 16 degrees C. Moreover, from the time-temperature tolerance chart, a Q10 value of 4.48 was derived. These data were confirmed applying the continuous method, where the headspace around the fruit was automatically monitored during the preservation of slices in a storage cell at controlled temperatures. In this case, we observed that, in correspondence with the stability time, a clear change in normalised sensor signals occurred and also this kinetics was parameterized using a second derivative function. With this approach, the freshness of food was maintained for about 5 days at 4 degrees C, 2 days at 8 degrees C and 1 day at 16 degrees C.
