New Technology in Sensing Odours: From Human to Artificial Noses (original) (raw)

2006, Floriculture, Ornamental and Plant Biotechnology: Advances and Topical Issues Vol. IV

The Human nose is much more complicated than other human senses like the ear and the eye. It is still the primary 'instrument' to assess the smell of various products. Sensory evaluation using the human sense of smell is subjective; careful design and rigorous training of assessors allows it to become a more objective, but still expensive option. Instrumental methods, such as gas chromatography/ mass spectrometry (GC/MS), are also expensive and require trained personnel. The concept of the electronic nose has attracted attention in many branches of industry for its potential in routine odour analysis. Being first reported in 1982 by Persaud and Dodds (Persaud 1982), the research in the field rapidly increased, and a number of companies have now been established to commercialize the concept. Basically, an electronic nose has the mammalian olfaction as a model and consists of a sensor array with partially overlapping selectivities and a pattern recognition system. It can be trained to detect and discriminate a large number of both simple and complex odours. The electronic nose concept is widely used as an analytical tool in industry today. The commercialization of the electronic nose began in 1993 as the concept became widely accepted as an effective instrument for detection and estimation of olfaction. This chapter describes the general setup of an electronic nose. It consists of an aroma extraction technique or air flow system which switches the reference air and the tested air; an array of chemical sensors which transform the aroma into electrical signals; an instrumentation and control system to measure the sensors signal and a pattern recognition system to identify and classify the aroma of the measured samples. This system has been used to identify several flower and plant aromas.