Uso de huellas dactilares instrumentales para medidas analíticas de similitud. Aplicación en problemas relacionados con la calidad alimentaria

Abstract

The present Doctoral Thesis entitled "Use of instrumental fingerprints for analytical measures of similarity. Application in problems related to food quality " has delved into the resolution of analytical problems related to food quality such as olive oil and hazelnut from two different perspectives: (i) the development and application of Certified Reference Materials and (ii) the use of agnotized instrumental fingerprints in terms of their independence from the moment of acquisition and the state of the equipment used in the analysis. The aim of this study is to apply the instrumental fingerprint methodology obtained using chromatographic techniques (GC and LC) with different detection systems (FID, MS and DAD) of different families of compounds present in foods such as volatile organic compounds from olive oil and hazelnuts samples, and triglycerides, chlorophylls, pheophytin and carotenes in olive oil samples. The interest in these families is due to the fact that they are fundamentally associated with organoleptic properties/attributes. The data matrices corresponding to instrumental fingerprints processed under the instrumental agnostizing approach have been investigated by applying several pattern recognition techniques including principal component analysis (PCA) and hierarchical cluster analysis (HCA) for unsupervised study and Soft independent modelling by class analogy (SIMCA), partial least squares-discriminant analysis (PLS DA) and supported vector machines (SVM) for classification/discrimination as examples of tools for supervised pattern recognition. The potential for transferring the research results of part of the contents of this thesis has also been taken into account. As proof of this, the use of similarity indices and similarity profiles has been proposed as suitable tools for: (i) the harmonisation of tasting panels, essential elements of the sensory analysis applied to the virgin and extra virgin olive oil sector, and (ii) as a potential tool for the traceability of the oils themselves.