Tomato waste may prove fuel of the future

What if you could use fruits as a source of energy to power your gadgets? A team of scientists has found that rotten or damaged tomatoes could soon be rescued from the bin and used to generate electricity.

The team's pilot project involves a biological-based fuel cell that uses tomato waste left over from harvests in Florida.

Researcher Namita Shrestha from the South Dakota School of Mines and Technology said, "We have found that spoiled and damaged tomatoes left over from harvest can be a particularly powerful source of energy when used in a biological or microbial electrochemical cell. The process also helps purify the tomato-contaminated solid waste and associated waste water."

Tomatoes are a key crop in Florida, notes researcher Venkataramana Gadhamshetty, who's leading the project. He stresses that the project is important to the state because Florida generates 396,000 tons of tomato waste every year, but lacks a good treatment process.

The team developed a microbial electrochemical cell that can exploit tomato waste to generate electric current. Shrestha explained that microbial electrochemical cells use bacteria to break down and oxidize organic material in defective tomatoes.

According to calculations by Shrestha, there is theoretically enough tomato waste generated in Florida each year to meet Disney World's electricity demand for 90 days, using an optimized biological fuel cell.

"Our research question at this time is to investigate the fundamental electron transfer mechanisms and the interaction between the solid tomato waste and microbes," Gadhamshetty notes.

They plan to improve the cell by determining which of its parts - electrode, electricity-producing bacteria, biological film, wiring, are resisting the flow of electricity. Then they will tweak or replace that part.

The study is presented at the 251st National Meeting & Exposition of the American Chemical Society (ACS).