Food‐Safe Bioimpedance Monitoring of Table Grapes and Their Post‐Harvest Aging

ABSTRACT The integration of digital technologies into agriculture is reshaping post‐harvest monitoring, enabling sustainable, non‐destructive fruits and vegetables quality assessment methods. Electrochemical Impedance Spectroscopy (EIS) constitutes a powerful tool to evaluate physicochemical changes in fruits and their quality during ripening and rotting. However, its widespread application is limited by the use of non‐biodegradable, short‐term adhesive electrodes and low‐throughput, contact‐inconsistent setups. Here, we present an EIS platform combining edible adhesive electrodes and a food‐safe sensorized soft gripper for monitoring fruit without damage. The electrodes are fabricated from food‐derived materials such as zein and activated carbon (E153) and are key to allow safe and reproducible access to fruit bioimpedance. The soft gripper, coated with food‐contact safe conductive materials including gold foil (E175), polydimethylsiloxane, and activated carbon, allows reliable electrical probing. Table grapes were selected as a non‐climacteric study case crop to evaluate post‐harvest physiological changes under different storage temperatures. Our system enabled continuous monitoring over several days and detected significant impedance changes within the first 24 h, with refrigerated grapes showing a slower spectral variation with respect to those stored at room temperature. These findings demonstrate the potential of the proposed food‐compatible EIS platform for real‐time fruit quality monitoring in sustainable post‐harvest supply chains.