| Institut Pascal |  |
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Theses
Développement d'une nouvelle méthode de mesure, modélisation et prédiction du potentiel d'oxydoréduction (pOR)en vue d'une amélioration raisonnée des procédés de transformation des produits carnés
Développement d'une nouvelle méthode de mesure, modélisation et prédiction du potentiel d'oxydoréduction (pOR)en vue d'une amélioration raisonnée des procédés de transformation des produits carnés
Abstract : AbstractThe purpose of this thesis was (1) to develop a new method for measuring the redox potentialas an indicator of color changes in fresh beef, (2) to model the impact of the factors influencing these changes and (3) to develop a tool to predict these changes. Meat juice has been shown to be a good mimetic medium for the study of color changes. Color change is faster in the juice than in the meat and faster at 20 °C than at 4 °C. Redox potential allows following color changes and a symmetry has been highlighted between this thermodynamic measure and color changes. Two color changes were observed, one from bright red to yellow/brown and the other from yellow/brown to dark red. The presence of microorganisms only accelerates an existing reaction during the first color change while it is essential for obtaining the second color change. The population causing the first change would be dominated by Pseudomonas and/or Brochothrix while lactic bacteria would be responsible for the second one. A predictive model of color changes (a*) was developed using the Jones Nachtscheim experimental design and the Gompertz equation. Non-linear optimization has shown that partial pressure of oxygen is the predominant factor in the regression (> 80%) before the storage temperature, the time of maturation under vacuum and the cutting angle of the meat.
Keywords :
Meat products
File
2020CLFAC088_CUCCI.pdf
Version validated by the jury (STAR)