Electricity generation from defective tomatoes

•Defective tomatoes generate electricity.•Redox-active species in culled tomatoes enhance their oxidation.•Peel and seed in culled tomatoes impedes their oxidation.•The study compares oxidation behavior of solid culls with pure substrates.

The United States faces a significant burden in treating 0.61 billion kg of defective tomatoes (culls) every year. We present a proof-of-concept for generating electricity from culled tomatoes in microbial-electrochemical systems (MESs). This study delineates impedance behavior of the culled tomatoes in MESs and compares its impedance spectra with that of soluble substrates (dextrose, acetate, and wastewater). A series of AC and DC diagnostic tests have revealed the superior performance of the culled tomatoes compared to the pure substrates. Cyclic voltammetry results have indicated the active role of indigenous, diffusible redox-active pigments in the culled tomatoes on overall electricity production. Electrochemical impedance spectroscopy results have elucidated the role of peel and seed on the oxidation behavior of the culled tomatoes.

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