title: Sensory intensity assessment of olive oils using an electronic tongue.
abstract: Olive oils may be commercialized as intense, medium or light, according to the intensity perception of fruitiness, bitterness and pungency attributes, assessed by a sensory panel. In this work, the capability of an electronic tongue to correctly classify olive oils according to the sensory intensity perception levels was evaluated. Cross-sensitivity and non-specific lipid polymeric membranes were used as sensors. The sensor device was firstly tested using quinine monohydrochloride standard solutions. Mean sensitivities of 14±2 to 25±6 mV/decade, depending on the type of plasticizer used in the lipid membranes, were obtained showing the device capability for evaluating bitterness. Then, linear discriminant models based on sub-sets of sensors, selected by a meta-heuristic simulated annealing algorithm, were established enabling to correctly classify 91% of olive oils according to their intensity sensory grade (leave-one-out cross-validation procedure). This capability was further evaluated using a repeated K-fold cross-validation procedure, showing that the electronic tongue allowed an average correct classification of 80% of the olive oils used for internal-validation. So, the electronic tongue can be seen as a taste sensor, allowing differentiating olive oils with different sensory intensities, and could be used as a preliminary, complementary and practical tool for panelists during olive oil sensory analysis.
authors.affiliation: Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra, Portugal; CEB-Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Ana C A
authors.initials: AC
authors.lastname: Veloso
authors.affiliation: Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, 5301-855 Bragança, Portugal; CQ-VR, Centro de Química - Vila Real, University of Trás-os-Montes e Alto Douro, Apartado 1013, 5001-801 Vila Real, Portugal.
authors.forename: Luís G
authors.initials: LG
authors.lastname: Dias
authors.affiliation: CIMO-Mountain Research Centre, Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, 5301-855 Bragança, Portugal.
authors.forename: Nuno
authors.initials: N
authors.lastname: Rodrigues
authors.affiliation: CIMO-Mountain Research Centre, Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, 5301-855 Bragança, Portugal.
authors.forename: José A
authors.initials: JA
authors.lastname: Pereira
authors.affiliation: LSRE-Laboratory of Separation and Reaction Engineering-Associate Laboratory LSRE-LCM, Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, 5301-855 Bragança, Portugal. Electronic address: peres@ipb.pt.
authors.forename: António M
authors.initials: AM
authors.lastname: Peres
mesh_terms: D000465:Algorithms; D032701:Biomimetics / Q000295:instrumentation*; D016002:Discriminant Analysis; D055615:Electrical Equipment and Supplies; D063427:Food Quality; D000069463:Olive Oil / Q000737:chemistry*; D010636:Phenols / Q000032:analysis; D013649:Taste; D014059:Tongue
chemical_list: D000069463:Olive Oil; D010636:Phenols
keywords: Linear discriminant analysis; Potentiometric electronic tongue; Sensory intensity perception classification; Simulated annealing algorithm; Single cultivar extra virgin olive oil