A Low-Cost Instrument for Estimating the Starch Content of Cassava Roots Based on the Measurement of RF Return Loss

The problem of simply and reliably estimating starch content of cassava roots in the field is addressed by the development of a low cost test instrument that measures return loss at radio frequencies using a coaxial probe. A clear relationship between starch content of cassava roots and the measured return loss of root samples at a specific frequency of 30 MHz is first verified experimentally. A prototype test instrument is then designed with goals of portability, low cost and simplicity of use. The test instrument displays starch content in 5 categories, from “low” to “high” using an array of 5 LEDs. The performance of the test instrument is experimentally verified in the field and a reliable correlation between cassava root starch content and LED indication is demonstrated.