介电特性与食品原料的新鲜度及腐烂程度间存在密切关系，相对介电常数在适当的频率范围内, 对一些食品的腐烂程度有较好的相关性, 可以用于评价食品的内部品质。介电特性与水分含量变化规律具有相关性，电容值的变化趋势与水分的变化相同，两者存在极显著的线性相关性。

There is a close correlation between the dielectric properties and the freshness of food materials within suitable frequency range and thus the dielectric properties can be used to evaluate the quality of the foods. The purpose is to acquire the correlation of dielectric properties and moisture content for the automatic and nondestructive monitoring of agricultural products．