Heat transfer analysis depending on electrical conductivities of tofu coagulation process during ohmic heating
Ohmic heating has been increasingly used in food processing in recent years because of its ability to heat food quickly and uniformly. As a method of heating by internal heat source, the heating rate is affected by many factors, such as food ingredients, internal temperature, the supply voltage, and power frequency. As a possible application of ohmic heating, the heating process of Tofu producing was studied. Tofu is produced by heating soy milk containing a coagulating agent. In this study, mixture of soymilk and MgCl2 was selected as the sample. During ohmic heating of tofu, the electrical conductivity changes as the concentration of MgCl2, supplied voltage and power frequency changes. The electrical conductivity of the sample was increased along with the concentration of MgCl2 and the power frequency, however, no significant changes in electrical conductivity took place during coagulation process. We also analyzed the temperature distribution using the heat transfer equation involving the internal heat generation owing to ohmic heating. In this calculation, the internal heat generation was related with the electrical conductivity of the sample and the supplied voltage. Results showed good agreement between the simulation and experimental results, and it shows that the temperature prediction method is possible to use the analysis of ohmic heating.
Ohmic heating tofu electrical conductivity temperature distribution
Wenchuan Yang Mika Fukuoka Noboru Sakai
Department of Food Science and Technology Tokyo University of Marine Science and Technology 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
国际会议
The Ninth Asian Thermophysical Properties Conference(第九届亚洲热物理性能会议 ATPC 2010)
北京
英文
445-449
2010-10-19（万方平台首次上网日期，不代表论文的发表时间）