Perceptual odour interactions and objective mixture analysis

Abstract Predicting the outcome of mixing odours is difficult and success is infrequent. Current methods for predicting the importance of individual constituents of mixtures to overall aroma are commonly based on threshold and concentration data and none incorporate information on the perceptual interactions of the constituents. The present paper describes the types of perceptual interactions that occur in mixtures and discusses two mechanisms, Spatial and Temporal Filtering, which have a significant impact on the perception of individual constituents and overall aroma. These mechanisms together with the recent finding that humans can only identify up to three or four odorants in a mixture, indicate that substantial fundamental studies of odour mixtures are needed to systematically compile information on the interactions of odours to provide a basis for the development of objective methods for measuring the role of individual constituents in mixtures.