title: A novel approach for honey pollen profile assessment using an electronic tongue and chemometric tools.
abstract: Nowadays the main honey producing countries require accurate labeling of honey before commercialization, including floral classification. Traditionally, this classification is made by melissopalynology analysis, an accurate but time-consuming task requiring laborious sample pre-treatment and high-skilled technicians. In this work the potential use of a potentiometric electronic tongue for pollinic assessment is evaluated, using monofloral and polyfloral honeys. The results showed that after splitting honeys according to color (white, amber and dark), the novel methodology enabled quantifying the relative percentage of the main pollens (Castanea sp., Echium sp., Erica sp., Eucaliptus sp., Lavandula sp., Prunus sp., Rubus sp. and Trifolium sp.). Multiple linear regression models were established for each type of pollen, based on the best sensors' sub-sets selected using the simulated annealing algorithm. To minimize the overfitting risk, a repeated K-fold cross-validation procedure was implemented, ensuring that at least 10-20% of the honeys were used for internal validation. With this approach, a minimum average determination coefficient of 0.91 ± 0.15 was obtained. Also, the proposed technique enabled the correct classification of 92% and 100% of monofloral and polyfloral honeys, respectively. The quite satisfactory performance of the novel procedure for quantifying the relative pollen frequency may envisage its applicability for honey labeling and geographical origin identification. Nevertheless, this approach is not a full alternative to the traditional melissopalynologic analysis; it may be seen as a practical complementary tool for preliminary honey floral classification, leaving only problematic cases for pollinic evaluation.
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. Electronic address: ldias@ipb.pt.
authors.forename: Luís G
authors.initials: LG
authors.lastname: Dias
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: CIMO-Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, 5301-855 Bragança, Portugal.
authors.forename: Mara E B C
authors.initials: ME
authors.lastname: Sousa
authors.affiliation: CIMO-Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, 5301-855 Bragança, Portugal.
authors.forename: Letícia
authors.initials: L
authors.lastname: Estevinho
authors.affiliation: LAQUIPAI - Laboratório de Química Inorgânica Pura e de Aplicação Interdisciplinar, Departamento de Química, Faculdade de Ciências da, Universidade do Porto, Rua Campo Alegre n°. 687, 4169-007 Porto, Portugal.
authors.forename: Adélio A S C
authors.initials: AA
authors.lastname: Machado
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: D004581:Electronics; D006722:Honey / Q000032:analysis*; D011058:Pollen / Q000737:chemistry*
keywords: Electronic tongue; Honey; Multiple linear regression models; Pollen profile; Simulated annealing algorithm