Titre :
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Prediction of chilling times of foods in situations where evaporative cooling is significant. Part 3. Applications
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Auteurs :
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S. Chuntranuluck ;
C. Wells ;
A. Cleland
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Type de document :
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article/chapitre/communication
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Année de publication :
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1998
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Format :
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p. 143-157
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Langues:
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= Anglais
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Catégories :
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GENIE DES PROCEDES FRIGORIFIQUES
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Mots-clés:
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PRODUIT ALIMENTAIRE
;
TEMPS DE CONGELATION
;
PREVISION
;
METHODE AUX DIFFERENCES FINIES
;
EVAPORATION
;
EXPERIMENTATION
;
MODELE
;
ACTIVITE DE L'EAU
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Résumé :
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Heuristics (rules of thumb) are proposed for extending the chilling time prediction method proposed in Part I and tested for model substances in Part 2 to real foods with non-unity water activity. Guidance is given for selecting three water activity values-one representing the maximally wetted starting condition, one representing the mean value during the active chilling phase, and the third describing the surface condition in the quasi-equilibrium state reached at the end of chilling. Chilling rimes of a product retaining a well-wetted surface during chilling (peeled carrots) were predicted to within approx. -10 to +15% of measured values. At least part of this difference can be attributed to experimental error: For a product not retaining a well-wetted surface due to skirt resistance (unpeeled carrots) predictions of only slightly lower accuracy were achieved. Accurate prediction of chilling time across a wide range of conditions by a simple algebraic prediction method is possible in spite of the complexity introduced by evaporative cooling at the product surface with water activity less than I.
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Source :
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Journal of Food Engineering, vol. 37
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