Classification of rice wine according to different marked ages using a novel artificial olfactory technique based on colorimetric sensor array

A novel artificial olfactory technique based on colorimetric sensor array was developed for the classification of Chinese rice wine according to different marked ages. The sensor array was composed of nine porphyrins or metalloporphyrins materials and six pH indicators. When the sensor array was exposed to rice wine for several minutes, a colour change profile for each sample was obtained by differentiating the image of sensor array before and after exposure to the head-gas of the sample. The values of RGB (i.e., red, green, and blue) colour components were extracted from each dye in colour change profiles, and they were analysed using principal component analysis (PCA) and linear discriminant analysis (LDA). In contrast to PCA, LDA obtained an optimum classification result. This research shows that the artificial olfactory technique based on colorimetric sensor array has a powerful potential in the quality evaluation of rice wine.