Changes Of Microstructure And Dielectric Properties Of Banana Chips During Microwave Freeze Drying

摘要

This experimental study investigated the dynamic changes of microstructure and dielectric properties during microwave freeze drying of banana chips. The measurements were made at a microwave power setting of 2W/g at the highest drying temperature of 55 °C.A network analyzer and a light microscope were used to determine the dielectric properties and structure, respectively. The dielectric properties, ε′ and ε′′, and the size of individual cells get smaller as the drying process continues; this occurs especially significantly during the initial 3 – 4 h of drying. The trend of dielectric properties and microstructure of samples during drying can be used to provide a precise indication of the drying stage during microwave freeze drying.