A Study On The Dielectric Properties And The Application Of Vegetables

Dielectric property is the corresponding reaction of the charge of biology molecular to the external electric field. Studying the dielectric property of food is in favor of analyse and control its quality as well as to apply it to processing food. This technology is widely adopted and has its unique advantage in storage, electric processing, quality inspecting and grading. Inspection by using the electric physical property provides a major method to the automation and precision control of food processing. Now, the research at home is just kick-off, and the depth and width is far behind that of the world, especially the dielectric property research of vegetables.The possibility to control the conditions of process non-destructively with lower cost was put forward. We also get the optimization method of operating condition of dried foods for quality inspecting by using dielectric property. A new technique for nondestructive inspecting internal quality of the vegetable, deep-fat frying and drying process of the vegetable online based on the dielectric property at low frequency range is put forward for the first time. This technique would be beneficial for food science and food industry.According to the major factors affecting the dielectric property, parallel plate electrodes is adopted to determine the capacitance and moisture content of 20 kinds of food material, and the DES100 is used to test the electric property of the slice of vegetables. The result shows that the physical and chemical property both have an impact on the dielectric property as well as the testing condition. The relation is that the dielectric constant increases with the temperature going up, and decreases with the frequency rising. The result of the self-made electrode system is reliable. When the testing condition is fixed, the moisture content is the key factor affecting the dielectric property, the dielectric constant drops with the moisture decrease and there is a linear relationship between them. The same material can be described with the same fix mark equation, and the corn food is Y=51.708X— 49.531 (X, the dielectric property, Y, the moisture content) .There is no fixed mark equation suitable for various kinds of fruits and vegetables due to their different texture. There is a fixed mark equation between dielectric constant and moisture content suitable for the same kind of vegetable. The method of calculating the moisture content according to the capacitance of food material, without damaging the food texture online is feasible in theory.Study on relationship between dielectric properties and quality inspection of...