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Réactions à diffusion contrôlée dans des produits surgelés : comment des diagrammes d'état peuvent être utilisés pour la prévision de la stabilité pendant l'entreposage.

Diffusion-controlled reactions in frozen products: how state diagrams may be used for the prediction of storage stability.

Auteurs : CHAMPION D., SIMATOS D., LE MESTE M.

Résumé

The purpose of the work was to study the kinetics of two reactions: the ascorbic acid oxidation by Tempol and the alkaline phosphatase activity in concentrated sucrose solutions, in the temperature range from 20 to -24°C, and to compare measured rates and predictions based on the theory of diffusion-controlled reactions proposed by Atkins. Values for viscosity and diffusion were obtained from both measurements of viscosity and small-molecule translational diffusion coefficient in sucrose solutions at subzero temperatures and prediction using the Williams-Landel-Ferry relation. The relevance of using Tg' (the glass-transition temperature of the maximally freeze-concentrated solution) or a variable Tg (the actual glass-transition temperature corresponding to the concentration of the liquid phase) as the reference temperature in modelling the reactions kinetics is discussed.

Détails

  • Titre original : Diffusion-controlled reactions in frozen products: how state diagrams may be used for the prediction of storage stability.
  • Identifiant de la fiche : 2006-2534
  • Langues : Anglais
  • Source : Ice cream II. Proceedings of the second IDF International Symposium on Ice Cream.
  • Date d'édition : 2004

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