• Title/Summary/Keyword: ice dendrite size

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Mathematical Relationship between Ice Dendrite Size and Freezing Conditions in Tuna

  • Choi, Mi-Jung;Hong, Geun-Pyo;In, Dae-Sik;Min, Sang-Gi
    • Food Science and Biotechnology
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    • v.18 no.2
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    • pp.330-335
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    • 2009
  • The principal objective of this study was to investigate changes in ice dendrite size during the freezing of tuna, in order to formulate a mathematical model of ice dendrite size. The tuna was frozen via a uni-directional heat transfer. Thermogram analysis allowed us to determine the position of the freezing front versus time, which is referred to as the freezing front rate. The morphology of the ice dendrites was assessed via scanning electron microscopy after freeze-drying, and the retained pore size was measured as ice dendrites. We noted that the mean size of ice dendrites increased with the distance to the cooling plate; however, it decreased with reductions in the cooling rate and the cooling temperature. In addition, shorter durations of the freeze-drying process decreased the freezing front rate, resulting in a larger size of the ice dendrite pores that operate as water vapor sublimation channels. According to our results, we could derive a linear regression as an empirical mathematical model equation between the ice dendrite size and the inverse of the freezing front rate.

Changes in Ice Dendrite Size during Freezing Process in Gelatin Matrix as a Model Food System (모델 식품으로 젤라틴 매트릭스에서 동결과정에 따른 얼음 결정체 변화)

  • Min, Sang-Gi;Hong, Geun-Pyo;Choi, Mi-Jung
    • Food Science of Animal Resources
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    • v.28 no.3
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    • pp.312-318
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    • 2008
  • The objective of this study was to investigate the changes in ice dendrite size during freezing process in gelatin matrix as a model food system in order to provide mathematical relation between freezing condition and ice dendrite size. Gelatin gel as a model matrix was frozen in unidirectional Neumann's type of heat transfer. The thermograms' analysis allowed to determine the freezing temperature of the sample, the position of the freezing front versus time, and thus, freezing front rate. The morphology of ice dendrites was observed by scanning electron microscopy after freeze-drying. We observed that the means size of ice dendrite increased with the distance to the cooling plate; however, it decreased with the cooling rate and the cooling temperature. In addition, the shorter durations of the freeze-drying process was shorter decreeing the decreased the freezing front rate, resulted in their resulting in a larger pore size of the ice dendrite pores for the sublimation channel of that operate as water vapor sublimation channels. From these results, we could derive a linear regression as an empirical mathematical model equation between the ice dendrite size and the inverse of freezing front rate.

Growth kinetics and pattern formation of ice dendrites at small subcoolings (작은 과냉각 상태에서 ice dendrite의 결정 성장 특성)

  • 구기갑
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.5 no.3
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    • pp.197-208
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    • 1995
  • An experiment study of the dendrite growth of ice crystals growing in quiescent pure subcooled water was made at small subcoolings of 0.035 K < ${\Delta}T$ < 1.000 K. It was observed that the growth kinetics and morphology are functions of not only subcooling but also thermal convection. When the subcooling is less than 0.35K, it was found that effect of thermal convection on growth kinetics of ice dendrites becomes important. Quantitiative measurements of growth velocity, $V_{G}$, and tip radii of the edge and basal planes, $R_{1}$ and $R_{2}$, were made simultaneously as a function of subcooling.

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