Low-Cost Bio-Impedance Analysis System for the Evaluation of Fruit Ripeness

Novel non-destructive sensing techniques for fast and reliable fruit quality assessment are strongly needed to meet both production and consumer demands. In this direction, Electrical Impedance Spectroscopy (EIS) has shown a great potential in correlating the electrical parameters of fruits with their quality attributes. In this paper, the effect of aging on 9 bananas during a 12 days period was studied using a microcontroller-based EIS system. The bio-impedance was measured in the 100 Hz - 85 kHz frequency range and then correlated to the image analysis of the color evolution of such fruits. The results showed a good potential in monitoring the ripening process of bananas, with a good correlation of the low frequency points with the impedance evolution. Finally, both the impedance and the image analysis indicated the presence of a turning point in the ripening process.