Determination of permittivity values using microwave dielectric spectroscopy for assessing Apple and purple sweet potato quality parameters

Abstract

ABSTRACT A technique of microwave dielectric spectroscopy that allows us to determine the permittivity values of food is the open-ended coaxial probe. For this purpose, the measurement instruments that were used to determine the permittivity were a Vector Network Analyzer (VNA) at frequencies from 10 MHz to 3 GHz and a built in-house open-ended coaxial probe. In this work, the permittivity of a hundred and forty apples and eighty purple sweet potatoes were measured. The apple and purple sweet potato dielectric properties were correlated with their physicochemical properties to get to know if the quality parameters can be predicted from the permittivity. According to the data obtained, the correlation of the apples shows better results than the correlation of the purple sweet potatoes. These values mean that it is more likely to predict the physicochemical characteristic of the apple than the purple sweet potatoes.