Novel method based on polypyrrole‐modified sensors and emulsions for the evaluation of bitterness in extra virgin olive oils

A new methodology for the analysis of extra virgin olive oils has been developed. The method employs voltammetric electrodes based on polypyrrole (Ppy) used as sensing units of a sensory system. The array of sensors has been exposed to emulsions of extra virgin olive oils. The features observed in the cyclic voltammograms reflect the redox properties of the electroactive compounds (mainly antioxidants), which are present in the emulsions of extra virgin olive oils. Each sensor shows a characteristic electrochemical signal when exposed to the studied emulsions, providing a high degree of cross-selectivity. The principal component analysis (PCA) and the partial least squares discriminant analysis (PLS-DA) of the obtained signals have allowed the discrimination of the six extra virgin olive oils tested according to their degree of bitterness. Good correlations between electrochemical responses and the physico-chemical and sensorial characteristics of the virgin olive oils under study have been found.

► A novel method for bitterness characterization of virgin olive oils was developed. ► The electrochemical sensors were based on polypyrrole doped with several anions. ► For the electrochemical measurements emulsions of virgin olive oils were prepared. ► PCA allows discriminating virgin olive oils in function of bitterness. ► Good correlations between multisensor system and the bitterness were obtained.