ELECTRONIC NOSES AND THEIR APPLICATION TO FOOD

'Electronic nose' systems involve various types of electronic chemical gas sensors with partial specificity, as well as suitable statistical methods enabling the recognition of complex odours. As commercial ins truments have become available, a substantial increase in research int o the application of electronic noses in the evaluation of volatile co mpounds in food cosmetic and other items of everyday everyday life is observed. At present, the commercial gas sensor technologies comprise metal oxide semiconductors, metal oxide semiconductor field effect tra nsistors, organic conducting polymers, and piezoelectric crystal senso rs. Further sensors based on fibreoptic, electrochemical and bi-metal principles are still in the developmental stage. Statistical analysis techniques range from simple graphical evaluation to multivariate anal ysis such as artificial neural network and radial basis function. The introduction of electronic noses into the area of food is envisaged fo r quality control, process monitoring, freshness evaluation, shelf-lif e investigation and authenticity assessment. Considerable work has alr eady been carried out on meat, grains coffee, mushrooms, cheese, sugar , fish, beer and other beverages, as well as on the odour quality eval uation of food packaging material. (C) 1998 Academic Press.