Aroma discrimination by pattern recognition analysis of responses from semiconductor gas sensor array

Monitoring of black tea fermentation process using electronic nose

“…These studies were based on chemical analysis, and on-line instrumental monitoring of the fermentation aroma profile of black tea has not been attempted. At the same time, the new technology based on electronic nose has been attempted by scientists and it has shown excellent promise in many applications like food and beverages (Aishima et al, 1991;Borjesson, Eklov, Jonsson, Sundgren, & Schnurer, 1996;Pearce, Garner, Friel, Bartlett, & Blair, 1993;Pisanelli, Qutob, Traverse, Szyszko, & Persaud, 1994;Nanto, Shokoshi, & Kawai, 1991;Olafsson, Martinsdottir, Olafsdottir, Sigfusson, & Gardner, 1992;Stetter, Findlay, Shroeder, Yue, & Penrose, 1993;Winquist, Hornsten, Sundgren, & Lundstrom, 1993). But reports of applications of electronic nose for black tea are very few in number and the earlier works were mainly focused on characterization of smell of finished tea.…”

Sensors: From biosensors to the electronic nose

“…The electronic nose produces a tri-dimensional (n, k, t) output matrix, Shurmer and Gardner, 1992;Wilson et al 2000;Pearce et al 1993Guadarrama et al 2001Di Natale et al 2000Braggins et al 1999Vernat-Rossi 1996Luzuriaga and Balaban 1999Winquist et al 1990Bazemore et al 1997;Hines et al 1999;Sinesio et al 2000Aishima, 1991Singh et al 1996;Gardner et al 1992;Pardo et al 2000bLucas et al 1998Aparicio et al 2000Stella et al 2000;Pardo et al 2000aCarrapiso et al 2001Muhl et al 2000Magan et al 2001Zondervan et al 1999Philip et al 2000Schnürer et al 1999Werlein 2001 106 Grasas y Aceites where "n" is the number of samples, "k" is the number of sensors and "t" is the number of points supplied by each sensor. Such an amount of information requires a data pre-processing step to remove redundant and irrelevant information but retaining the original information as much as possible.…”

“…The different types of cluster analysis are: K-means clustering, block clustering and tree clustering (Aparicio 2000). Aishima (1991) used the cluster analysis to classify four types of coffee while Pearce et al (1993) used it to distinguish two kinds of lagers. Cluster analysis has also been used to study the similarities between sensors in order to select the sensors with the highest sensitivity from each batch of sensors and so avoiding redundancy (Chaudry et al 2000;Penza et al 2000).…”

PH—Postharvest Technology

“…A more recent development in this area is the application of arti"cial neural networks (ANN) techniques to the processing of data from a sensor array (Gardner et al, 1990;Nakamoto et al, 1993;Gardner & Bartlett, 1991;Sundgren et al, 1991;Aishma, 1991;Keller et al, 1995b). Also referred to as connectionist architectures, parallel distributed processing, and neuromorphic systems, an arti-"cial neural network (ANN) is an information-processing paradigm inspired by the way the densely interconnected, parallel structure of the mammalian brain processes information.…”