Measurements and Analyses of Changes in Thermo-physical Properties and Process of Heat Transfer for Foods during Cooking

为了简化食品制备过程中的结构和操作复杂性，尝试用模型系统定量分析食品在烹饪过程中的传热动力学。本研究的具体内容可以概括如下：1.考虑到水分含量对食品传热的影响，尝试建立了一系列食品加热模型。新制备的模型是浓缩的分散体系之一，其由悬浮在水和玉米油的任选混合物中的小麦粉和可可粉的等效混合物组成，而模型中的水分能够在约7至50重量%之间变化，而在加热期间没有任何模制形状的失效。通过测量，明确了模型的热扩散率与水分之间的相关性.为了检测热通量al，提供了用于模拟各种烹饪的加热装置的组件 ...更多信息 通过一维轴在食品材料中从热传递介质。所提供的加热装置可以在诸如锅加热、蒸、煮、飞或烘烤的过程中在沿着加热介质的一维轴的食物中的0 mm、1 mm、3 mm和5 mm的不同位置处以合理的再现性跟随温度的升高。研究发现，在不同加热方式下，模型内部不同位置的温升和一些实际食品的温升可以用一个指数函数来概括，该指数函数是由热通量的延迟现象推导出来的.对应于延迟时间的新推导的方程的时间常数取决于从加热介质的距离为每个样品进行测试，而实验获得的时间常数的值是深切关注的每个样品在内部位置的热扩散率。这一结果表明，如果能够使用该指数函数在更实际的情况下确认上述相关性，则可以确定估计烹饪过程中食物材料内部温度的变化。少

An attempt was made to analyze quantitatively the kinetics of heat transfers of foods in cooking procedure using model systems so as to simplify the constitutional and operational complexities occurring during food preparations. The details of this study can be summarized, as follows :1. It was tried to prepare a series of food models for heating in view of the moisture content, which may play a significant role in the heat transfer of foods. The newly prepared models were one of the concentrated disperse systems consisting of an equivalent mixture of wheat flour and cocoa powder suspended in the optional mixtures of water and corn oil, while the moisture in the models was able to vary from ca.7 to 50 wt % without any failure of molded shape during heating. The measurements were made to clarify the correlation between the thermal diffusivity and moisture of the models.2. An assembly of the heating device for modeling a variety of cooking was provided in order to detect the heat flux al … More ong by the one-dimensional axis in food materials from the beat transfer media. The heating device provided could follow the increasing temperature with reasonable reproducibility at the different locations of 0 mm, 1 mm, 3 mm and 5 mm along by the one-dimensional axis in the foods from the heating media during the procedure such as pan heating, steaming, boiling, flying, or baking.3. It was found out that the increasing temperature at the different inside-locations of the models and some practical foods during the various types of heating could be generalized by an exponential function, which was derived from the retardation phenomenon of thermal flux.4. The time constant corresponding to the retardation time of the newly derived equation depends on the distance from the heating medium for each sample to be tested, while the value for the time constant obtained experimentally is deeply concerned with the thermal diffusivity of each sample at an inside-location. This result suggests that if the above correlation can be confirmed with more practical cases using this exponential function, it will be sure to estimate changes in the inside temperature of food materials during cooking. Less