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Détermination de la qualité de la betterave sucrière par spectroscopie proche infrarouge et chimiométrie

Abstract : Since 1964, the official method for the determination of beet sucrose content, i.e. polarimetry, uses lead acetate. However, because heavy metals pollute the environment, the use of lead acetate is likely to be banned in the near future. Near infrared spectroscopy (NIRS) is a suitable replacement for this method. The first part is a feasibility study to determine beet sucrose content by NIRS. Several spectral pre-processing and regression methods were tested in order to produce an accurate prediction of sugar content. Analyse of variance and Fisher's tests were used to compare models (bias and Standard Error of Prediction corrected for bias) in terms of statistical significance. A model, developed with spectra pre-treated by SNV and second derivative, gave the most accurate results on a validation set of 525 samples. The standard error of prediction was 0.10 g of sucrose / 100 g of fresh beet over a large concentration range (14 – 21 g / 100 g). The transfer of this calibration to an industrial application was studied in a second part. Different alternative solutions were evaluated: among these were bias correction of predicted values, spectral correction and development of robust models. The solution adopted was a robust model developed using a calibration set containing spectra from several instruments. The conclusion reached was that prediction of the polarimetric measurement using several NIRS instruments is feasible in an industrial context. Finally, the automation of NIRS measurements using an automatic filling system coupled to a spectrometer was studied. In the last part, the determination of several components contents, which determine sugar beet quality, is studied. Brix, Nitrogen content and others parameters are evaluated by NIRS. Supervised pattern recognition methods are used to determine qualitative parameters like disease resistance, geographical origin and crop period.
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Contributor : Yves Roggo <>
Submitted on : Monday, May 17, 2004 - 6:29:41 PM
Last modification on : Wednesday, November 25, 2020 - 3:01:40 AM
Long-term archiving on: : Friday, April 2, 2010 - 8:50:41 PM


  • HAL Id : tel-00006113, version 1



Yves Roggo. Détermination de la qualité de la betterave sucrière par spectroscopie proche infrarouge et chimiométrie. Autre. Université des Sciences et Technologie de Lille - Lille I, 2003. Français. ⟨tel-00006113⟩



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