NONDESTRUCTIVE MICROWAVE MEASUREMENT OF MOISTURE-CONTENT AND MASS OF SINGLE PEANUT KERNELS

Principles for determining moisture content and mass of individual peanut kernels by microwave resonator measurements are discussed, and data are presented showing the application of these principles. By measuring the shift in the resonant frequency and the change in the cavity transmission characteristics when a peanut is inserted into the cavity, it is possible to obtain the moisture content of the kernel independent of its mass and apparently independent of peanut type, as far as Runner and Virginia market types are concerned. It is also possible to determine the kernel mass independent of kernel shape simultaneously with the moisture determination. Moisture contents in the range from 4 to 14%, wet basis, were determined with an uncertainty of 0.9% moisture, and the uncertainty in the mass determination was less than 0.05 g.