Research Initiation Award: A Fundamental Investigation of the Freezing Process in Food Materials

该项目的目标是开发蛋白质、脂肪和碳水化合物食品成分在冷冻过程中的热性质的表达式。这些食品成分被认为是食品原料的组成部分。具体目标是：1)确定用于食品冷冻研究的代表基本食品成分的标准材料；2)构建这些材料的相图；3)建立每种测试材料的温度和未冷冻水分含量之间的关系；以及，4)建立这些材料在冻结过程中的热性能关系。第一项任务是确定以蛋白质、脂肪和碳水化合物为基础的测试材料，这些材料代表食物的基本成分。然后，通过差示扫描量热法实验确定这些材料的不同浓度的相变温度，从而绘制相图。热物性的表达式将基于从这些相图中形成的温度和水分之间的热力学关系。积木的概念代表了一种研究冷冻过程的新方法，它在扩大食品冷冻数学模型的实际应用方面具有巨大的潜力，这些数学模型需要了解食品的热性质。首先，这一概念的使用消除了提供不同食品的凝固点下降数据的需要，其次，它可以导致简化的热物性关系，这将促进复杂的多维冷冻模型的使用。

The objectives of this project are to develop expressions for the thermal properties of protein, fat, and carbohydrate food components during freezing. These food components are considered to be the building blocks of food materials. The specific objectives are to: 1) to identify standard materials for use in food freezing studies which represent the basic food components; 2) to construct phase diagrams for these materials; 3) to develop relationships between temperature and unfrozen moisture content for each test material; and, 4) to develop thermal property relationships for these materials during freezing. The first task is to identify protein, fat, and carbohydrate based test materials which represent the basic components of foods. Then, phase diagrams will be formulated from phase transition temperatures determined for different concentrations of these materials from differential scanning calorimetry experiments. The expressions for the thermal properties will be based on thermodynamic relationships between temperature and moisture content formulated from these phase diagrams. The building block concept represents a novel approach to the investigation of the freezing process, and it has great future potential for the expanded practical use of mathematical food freezing models which require knowledge of the thermal properties. First of all, use of this concept eliminates the need for freezing point depression data to be available for different food products, and secondly, it could result in simplified thermal property relationships which would facilitate the use of complex multi-dimensional freezing models.