Measurement of Dielectric Properties of Microcrystalline Cellulose (MCC) and Anhydrous Lactose at Microwave Frequency

The complex dielectric properties of Microcrystalline Cellulose (MCC) and Anhydrous Lactose were measured using a resonance frequency microwave-based sensor. The fan graphs relating the dielectric properties and physical properties of the powder were established under different bulk densities and moisture content. After the anhydrous lactose powder is exposed to moisture, it is converted to Ą-monohydrate lactose which is detected as a shift in the curves of the fan graph over time indicating a lower free water content in the powder. Conversely, there is no chemical structural change in the MCC powder over time after the addition of moisture. The fan graphs from the dielectric properties measurement are used for the simultaneous estimation of the bulk densities and the free water content in MCC and anhydrous lactose.