Nondestructive assessment of FRED® pear internal quality

A non-destructive instrumental chain was self-assembled to detect internal browning of pear during the postharvest storage. The radiofrequency region from 100Hz to 10 KHz was selected to investigate the fruit in depth. A batch of pear fruit belonging to conditioned storage were used for the present study (N=59). The internal defect was destructively assessed using the image analysis, soon after the electrical acquisition. The capacitive instrumental chain was composed of a hand-made parallel plate capacitor with adjustable gap, an LCR meter interfaced with a PC. The capacitive spectral data were collected and implemented to classify the pear fruit into two classes (K-means clustering analysis): defected and healthy. About 90% of samples were correctly classified. The multivariate Principal Component Analysis was exploited to show the two classes. Even if preliminary, the technique results promising to detect the internal browning in a non-destructive way. The instrument is rapid and inexpensive.