Recognition of odors emanating from 'La France' pear by semi-conducting polymer sensors

Odors emanating from La France pears were examined by the electric odor det ection system based on the adsorption and subsequent desorption of volatile compounds onto an array of proprietary semi-conducting polymers. La France pears were divided into three groups according to each storage treatment a fter being harvested. The first group was the pears stored for 115 d at 277 K, the second and third groups were the pears ripened in a chamber at 303 K for 1 d and 5d respectively, after the storage of 115 d at 277K. The ripe ning stages of pears in tree storage treatments were thought to be differen t. Pears of the first group were judged to be rather immature, those of the second group were a little mature, and those of the third group were matur e. Odors composed of volatile compounds emanating from pears were detected by the sensor array with 32 different polymers of electric odor detection s ystem. Odors were classified into three classes, which were dependent on th eir ripening stages, through distinctive odor pattern formed by 32 outputs. Copyright (C) 1998 IFAC.