Detection of flavour release from pectin gels using electronic noses

An electronic nose device developed in our laboratory was used to follow the flavour release of a multi-component essence encapsulated in pectin gels. Gelation kinetics of high-methoxylated pectin was followed by dynamic rheological measurements in presence and absence of flavour. A transition from a non-stabilized structure to a fully stabilized gel was observed at about 100min since mixing the gel components. Flavour release through different days after encapsulation was analyzed following the time evolution of the individual gas sensor’s signals of the e-nose and also the modification of the fingerprints associated to the whole response of the sensors array. The correlation with rheological measurements indicate that the e-nose is able to detect the gel formation and to follow the flavour release changes through aging of the material using principal component analysis (PCA). Artificial neural networks (ANN) analysis was also a successful approach to classify the samples in three categories related with the flavour composition and concentration in the gas phase.