title: Discrimination and characterisation of extra virgin olive oils from three cultivars in different maturation stages using Fourier transform infrared spectroscopy in tandem with chemometrics.
abstract: A methodology based on Fourier transform infrared (FTIR) spectroscopy, combined with multivariate analysis methods, was applied in order to monitor extra virgin olive oils produced from three distinct cultivars on different maturation stages. For the first time, this kind of methodology is used for the simultaneous discrimination of the maturation stage, and different cultivars. Principal component analysis and discriminant analysis were utilised to create a model for the discrimination of olive oil samples. Partial least squares regression was employed to design calibration models for the determination of chemical parameters. The performance of these models was based on the multiple coefficient of determination (R(2)), the root mean square error of calibration (RMSEC) and root mean square error of cross validation (RMSECV). The prediction models for the chemical parameters resulted in a R(2) ranged from 0.93 to 0.99, a RMSEC ranged from 1% to 4% and a RMSECV from 2% to 5%. It has been shown that this kind of approach allows to distinguish the different cultivars, and to clearly discern the different maturation stages, in each one of these distinct cultivars. Furthermore, the results demonstrated that FTIR spectroscopy in tandem with chemometric techniques allows the creation of viable and accurate models, suitable for correlating the data collected by FTIR spectroscopy, with the chemical composition of the EVOOs, obtained by standard methods.
authors.affiliation: CITAB - CITAB, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal. Electronic address: igouvinhas@utad.pt.
authors.forename: Irene
authors.initials: I
authors.lastname: Gouvinhas
authors.affiliation: Department of Physics, University of Trás-os-Montes and Alto Douro, 5000-801 Vila Real, Portugal; INESC Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal.
authors.forename: José M M M
authors.initials: JM
authors.lastname: de Almeida
authors.affiliation: Instituto Nacional de Investigação Agrária (INIA I.P.), Elvas, Portugal.
authors.forename: Teresa
authors.initials: T
authors.lastname: Carvalho
authors.affiliation: CITAB - CITAB, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal.
authors.forename: Nelson
authors.initials: N
authors.lastname: Machado
authors.affiliation: CITAB - CITAB, University of Trás-os-Montes and Alto Douro, 5001-801 Vila Real, Portugal.
authors.forename: Ana I R N A
authors.initials: AI
authors.lastname: Barros
mesh_terms: D002138:Calibration; D016018:Least-Squares Analysis; D015999:Multivariate Analysis; D000069463:Olive Oil; D010938:Plant Oils / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D000069463:Olive Oil; D010938:Plant Oils
keywords: Chemical parameters; Chemometrics; Cultivars; Extra virgin olive oil; Fourier transform infrared spectroscopy; Maturation stages