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Development of new chemometric methods - application to the spectroscopic characterisation of food quality

Abstract : The compression properties of PCT allow one to perform or just accelerate the calculations of multivariate methods in the case of very wide matrices, where the number of variables is much greater than the number of objects. The results can be back-transformed into the original vectors base giving exactly the same results as those obtained when using the standard method, without transformation. The ANOVA-PCA method facilitates the comparison of variance attributed to the Factors responsible for the differences between samples and the residual variance. It was used to study, by means of near infrared spectroscopy, the stability of reference materials stored under different conditions. The method was modified to allow the prediction of new samples, as well as to improve its ability to find significant Factors and understand sources of variability. Using one of the main concepts of the ANOVA-PCA method, the calculation of factor levels, a method used for multi-table analysis - CCSWA - was modified for the analysis of the Factor level matrices resulting from an experimental design. Mid-infrared spectroscopy was used for the analysis of food samples with the help of the heated ATR accessory. It allowed the study of the modifications of different edible oils after accelerated heating at different temperatures and simultaneous acquisition of spectra. The same ATR apparatus was used in the analysis of wine to study the effects of different technological treatments, namely Micro-oxygenation and Oak addition. After the evaporation of the main constituents, water and ethanol, directly on the ATR crystal, the peaks corresponding to minor components could be uncovered.
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Contributor : Ecole Agroparistech <>
Submitted on : Wednesday, July 29, 2009 - 8:00:00 AM
Last modification on : Wednesday, July 29, 2009 - 8:00:00 AM
Long-term archiving on: : Friday, October 19, 2012 - 12:40:17 PM

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Rui Climaco Pinto. Development of new chemometric methods - application to the spectroscopic characterisation of food quality. Chemical Sciences. AgroParisTech, 2009. English. ⟨NNT : 2009AGPT0030⟩. ⟨pastel-00005270⟩

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