Skip to Main content Skip to Navigation
Theses

Prédiction de la dégradation de la vitamine C en conditions de traitement thermique : étude en milieu modèle liquide entre 50 et 90 °C

Abstract : Vitamin C is often used as an indicator of labile nutrient retention in processed products because of its sensitivity to processing and conservation conditions. Understanding the behavior of vitamin C in complex matrices transformation processes is difficult, due to the importance of several parameters that affect its degradation (temperature, pH, exposure to light, the presence of oxygen and metal catalysts). Studying reactivity in a simple environment of known composition, under controlled conditions, is necessary for a better understanding of the mechanisms and for modelling in order to predict the impact of process parameters on the residual vitamin content. The present research aims at contributing to this goal for temperatures of a transformation process (50 - 90 °C), while decoupling the effect of concentration of dissolved oxygen (between 0 and 30%). To achieve this, a simple and rapid method of quantification of ascorbic acid (AA) and dehydroascorbic (DHAA) was first developed and validated. It allowed obtaining a reaction database for different couples of temperature and oxygen concentration, in a buffered and perfectly stirred medium. Two kinetic models were developed: a simple reaction model to predict the degradation of AA, and a more complex model taking into consideration both oxidative and thermal degradation pathways on the degradation kinetics of AA and DHAA. Both models show a good fit to experimental data and a strong correlation between k1 reaction rate of the oxidation reaction and the stoichiometric coefficient β relative to oxygen. A linear relationship between β and temperature was also proposed.
Document type :
Theses
Complete list of metadatas

Cited literature [124 references]  Display  Hide  Download

https://pastel.archives-ouvertes.fr/tel-03001158
Contributor : Abes Star :  Contact
Submitted on : Thursday, November 12, 2020 - 11:33:12 AM
Last modification on : Friday, November 13, 2020 - 3:24:25 AM

File

44072_GOMEZRUIZ_2016_archivage...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-03001158, version 1

Collections

Citation

Braulio Gomez Ruiz. Prédiction de la dégradation de la vitamine C en conditions de traitement thermique : étude en milieu modèle liquide entre 50 et 90 °C. Chimie analytique. AgroParisTech, 2016. Français. ⟨NNT : 2016AGPT0002⟩. ⟨tel-03001158⟩

Share

Metrics

Record views

38

Files downloads

22