Nondestructive Determination of the Maturity of the Durian Fruit in the Frequency Domain Using the Change in the Natural Frequency

This paper proposes a nondestructive technique to determine the stages of maturity of durian fruits. The presented methodology utilizes the electromagnetic scattering properties from the fruits over time for identification of the stage of maturity using its natural frequencies. Both simulation and experimental results show that the natural frequencies in the scattering responses change with the maturity of the durian fruit. Particularly, the change in the fundamental resonant frequency is used as a possible identification criterion for characterization of the stage of maturity. This is because the dielectric constant of the core of the fruit changes with its degree of maturity. In addition, the experimental results indicate that the variation of the dominant resonant frequency of durian fruits varies at different stages of maturity and this has the potential to be applied as a criterion to identify the stages of maturity.