Sensor analyses of volatile components derived from earth-almond Cyperus esculentus L. and carob Ceratonia siliqua L.

Abstract

 The Aroma Scanner A32 S, which mimics the human olfactory system, is based on conducting polymer sensor technology. The design of this electronic nose (capable of detecting and recognizing odours) is described. Two different products, earth-almond and carob (raw, and roasted for different lengths of time), were analysed by means of this electronic nose and by gas chromatography-mass spectrometry (GC-MS), in order to establish a basis of comparison between the two methods. After having analysed and compared the results obtained from both products, the Aroma Scanner was found to be a suitable method for monitoring the earth-almond roasting process, but not so effective at controlling carob roasting, as the correlation between sensor and GC-MS data was lower in the case of carob (R ²=0.74) than with earth-almond (R ²=0.98). This may be due to the inherent nature of the sample, as well as to the choice of signal processing technique. Therefore, the Aroma Scanner A32 S can be used as an efficient tool complementary to GC-MS analyses in recognizing aroma components of different products if the values concerning the volatiles formed in the roasting process do not appear very close to each other (Euclidean distance ≥0.5).