Capacitive Impedance Analysis for Non-Contact Assessment of Fruit Quality and Ripening

This article presents a comprehensive examination of the development of a non-contact measuring technique for determining fruit quality, with a particular focus on the impact of ambient temperature. Capacitance measurements were performed on banana and soap samples, and the behavior of series capacitance
$(C_{s})$
was analyzed across the 5–200 kHz frequency range. The data analysis revealed consistent trends in
$C_{s}$
, indicating that it is appropriate for future investigation. In addition, to improve data accuracy, compensation techniques were used to address the impact of temperature on the proposed method. To obtain compensated capacitance data, the remaining measurements were fitted with linear fitting coefficients determined from the first 18 hours of data. Both the banana and soap samples showed distinct trends when normalized and fitted data were compared. The banana's capacitance reduced by 6.76 % on the first day of testing and by a further 3.38 % on the last day, demonstrating the effect of aging on its biological tissues. The soap reference sample, however, showed constant capacitance behavior over time. These results highlight the significance of sample-specific analysis and temperature compensation in the capacitive measurement of fruit quality evaluation. The study offers useful details on non-contact measuring techniques for industrial applications and provides an outline for future studies to improve methods for evaluating fruit quality and advance industrial procedures.