MRI quantification of ice gradients in dough during freezing or thawing processes

• Published in: Journal of food engineering Vol. 71; no. 1; pp. 98 - 108
• Main Authors: Lucas, T., Grenier, A., Quellec, S., Le Bail, A., Davenel, A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-11-2005; Elsevier
• Subjects: air flow; Biological and medical sciences; Cereal and baking product industries; Environmental Sciences; equations; Food engineering; Food industries; freeze-thaw cycles; frozen dough; Fundamental and applied biological sciences. Psychology; General aspects; ice; Ice fraction; magnetic resonance imaging; MRI; temperature; thickness; transient flow; Transient thermal conditions; water activity; water content; Wheat dough; wheat products; Wheat dough; Ice fraction; MRI; Transient thermal conditions; Gradient; MRI: Transient thermal conditions; Cereal; Dough; Thawing; Ice; Wheat; Freezing; Quantitative analysis; IRM
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2004.07.027

The general aim of the work was to characterize the ice gradients in a dough stick during freezing and thawing processes in transient thermal conditions using MRI data. Firstly, the MRI signals obtained in steady-state thermal conditions for different MRI sequences were presented and discussed over the range [−15, +30
°C]. From these previous results, a direct relation between the MRI signal and the ice fraction was observed over the range [−10.8
°C,
θ
m] with
θ
m the initial freezing temperature. To validate the MRI method in transient thermal conditions, the ice fraction estimated from the MRI signal was converted into equivalent temperature (assuming thermodynamic equilibrium conditions) and compared with thermocouple temperature evolution during the freezing of a dough stick over the range [−10.8
°C,
θ
m]. Good agreement confirmed that ice fraction could be monitored from MRI signal in transient thermal conditions.