Optical path length and wavelength selection using Vis/NIR spectroscopy for olive oil's free acidity determination

© 2015 Institute of Food Science and Technology. Four different optical path lengths, namely 0.5, 1, 5 and 10 mm, were assayed for olive oil's free acidity determination using Vis/NIR spectroscopy. Results illustrated that the use of higher path length during spectra acquisition resulted in mor...

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Detalles Bibliográficos
Autor: García-Martín, Juan Francisco
Tipo de recurso: artículo
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/116607
Acceso en línea:http://hdl.handle.net/10261/116607
Access Level:acceso abierto
Palabra clave:Acidity
wavelength selection
olive oil
optical path length
NIR spectroscopy
Descripción
Sumario:© 2015 Institute of Food Science and Technology. Four different optical path lengths, namely 0.5, 1, 5 and 10 mm, were assayed for olive oil's free acidity determination using Vis/NIR spectroscopy. Results illustrated that the use of higher path length during spectra acquisition resulted in more accurate PLS models, especially when using solely the NIR region. The PLS model obtained with the NIR spectrum using the 10-mm cuvette was subjected to optimisation by Monte Carlo uninformative variable elimination (MCUVE) and successive projections algorithm (SPA). Both methods drastically reduced the number of spectral variables and markedly improved the performance of the PLS model, especially the SPA-PLS model, which achieved a SEP (0.051) quite close to SEL (0.048). Interestingly, only twelve of the eighty spectral variables selected by SPA were among the 314 variables provided by MCUVE. All in all, NIRS incorporated to MCUVE-PLS or SPA-PLS may be applied as an alternative method for the rapid determination of olive oil's free acidity.