Array of Different Polyaniline-Based Sensors for Detection of Volatile Compounds in Gummy Candy

Aroma in foodstuff is considered an essential attribute since it is closely related to the consumer acceptance of foodstuffs. Electronic nose (e-nose) system is composed by an array of gas sensor and has emerged as a promising alternative for the aroma volatile compounds recognition. In this study, a lab-made e-nose system comprising of an array of different polyaniline-based sensors has been used for aroma discrimination (apple, strawberry, and grape) in gummy candy. The sensor array was comprised by interdigitated graphite electrodes, using tracing paper substrate and sensitive layer of polyaniline (Pani) obtained by in situ and interfacial synthesis deposited by the in situ adsorption polymerization of aniline and layer-by-layer (LbL) methods. The sensors were characterized in relation to humidity and the Pani-in situ/PSS LbL layer presenting the higher sensitivity, a quite interesting feature for its use as a gas sensor. It has been demonstrated that the lab-made e-nose has been highly efficient in the discrimination of different concentrations of aromas added to gummy candies with excellent sensitivity and a limit of detection in the range of parts-per-billion, so demonstrated the applicability in food matrices.