Effect of fruit ripeness on electrical impedance spectrum parameters

This study aimed to reveal the mechanisms underlying changes in the electrical parameters of fruit during ripening. Plums and blueberries were selected as research objects, and their electrical parameters, firmness, water state, and microstructure with different maturities were measured. The observed relationships between fruit ripeness and electrical parameters were as follows: as fruit ripeness increased, the cell structure loosened, the number of gaps increased, membrane permeability increased, the distribution of free water became more scattered, and firmness gradually decreased. These factors led to increased cell fluid fluidity, shorter current flow paths, and lower impedance values. This study reveals the changes in various physiological indicators and electrical parameters of fruits during ripening and provides theoretical support for detecting fruit maturity using electrical parameters. These results are significant for the detection and grading of fruit maturity, extending the fruit preservation period, and developing rational fruit storage strategies. • Mechanism between electrical parameters and maturity is proposed. • Maturity is negatively correlated with impedance and Re. • Maturity affects the degree of dispersion of free water.