Array of Different Polyaniline-Based Sensors for Detection of Volatile Compounds in Gummy Candy Adriana Marcia Graboski 1 & Sandra Cristina Ballen 1 & Alexandra Manzoli 1 & Flavio M. Shimizu 2 & Claudio Augusto Zakrzevski 1 & Juliana Steffens 1 & Clarice Steffens 1 Received: 22 March 2017 /Accepted: 19 June 2017 # Springer Science+Business Media, LLC 2017 Abstract Aroma in foodstuff is considered an essential attribute since it is closely related to the consumer accep- tance 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 com- prising 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 com- prised 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 dis- crimination 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 demonstrat- ed the applicability in food matrices. Keywords Electronic nose . Aromas . Polyaniline . Array of sensors Introduction Due to an increasing competition in the globalized market, the food industry needs to continuously improve its products, aiming productivity and quality. The formulation of gummy candy, just like any other food product, should be carefully studied so that the interactions between the ingredients do not affect the release of odorous compounds, not interfering in its acceptance, percep- tion, and sensory quality. The evaluation profile, aroma monitor- ing, and quality in the gummy candy sector are key factors that lead the consumer to accept or not the product (Déléris et al. 2011; Yang et al. 2011; Pizzoni et al. 2015). The gummy candies use gelling agents, sweeteners, color- ing, and aromas in their formulation. Essential ingredients such as aromas are defined as substances or mixtures of sub- stances having odoriferous or sapid properties able to confer or enhance the taste of food (Periche et al. 2014). The evaluation of food aromas is usually carried out through sensory analysis by a group of trained panelists (Peris and Escuder-Gilabert 2009). However, several human factors such as individual variability decreased sensitivity due to prolonged exposure, fatigue, and mental state variables, making it a subjective, inconsistent, and unpredictable method (Banerjee et al. 2012). Due to limitations in sensory analysis methods, the use of laboratory analytical tools for the identification and determi- nation of volatile compounds of aromas is important. Chromatographic methods are commonly used as an alterna- tive for aroma identification (Reineccius 2005). These methods allow the chemical sample characterization for the identification and quantification of odorant compounds (Biniecka and Caroli 2011), having disadvantages such as high costs, time consuming, complex equipment, and un- trained laboratory personnel (Di Francesco et al. 2001; Pizzoni et al. 2015). * Clarice Steffens claristeffens@yahoo.com.br 1 Department of Food Engineering, URI - Campus of Erechim, Av. Sete de Setembro 1621, Erechim, RS 99709-910, Brazil 2 São Carlos Institute of Physics, University of São Paulo (USP), PO Box 369, São Carlos, SP 13566-590, Brazil Food Anal. Methods DOI 10.1007/s12161-017-0977-0