Whole Foods and other high-priced alternatives like Farmer's Markets sell imagery of pretty, thin people carrying bountiful produce, but the icky reality is that, unless it is canned or frozen, most food purchased rots quickly.

It is nature at work. Rot caused by microorganisms spoils half of all food harvested. The strange good news is that because plants also volatile organic compounds into the environment, science can detect those and tackle plant disease faster, which will prevent food loss. 

A new paper via Hebrew University of Jerusalem details the success of a biological sensor for early detection of hidden disease in potato tubers, one of Israel’s chief export industries.  But the potatoes they use as stock are imported from Europe, where most modern scientific methods are banned. Which means they are more likely to carry disease that causes rot and significantly reduces the potato’s quality. A new sensor detects the disease and can be used to inhibit the rot from growing and spreading.

The sensor relies on smart bioengineering and optics. When the sensor is exposed to an infected potato, a bacterial compound within lights up—with the strength of the luminescence indicating the concentration and composition of the rot. The biosensor will help identify diseased potatoes that do not yet have any external indications, and keep them away from healthy tubers.

To form the bacteria panel, the team created a compound of four genetically-engineered bacteria that measure biological toxicity. In this study, the biological sensor detected disease before there was any visible trace, and caused the optical sensor to shine twice as brightly as did the sensors in non-infected potatoes. Their capabilities were also demonstrated in a previous study that used the sensors to detect toxicity among artificial sweeteners in sport supplements.

According to the researchers, early discovery of disease--before the potatoes are exported to foreign markets or replanted, offers a significant advantage to food growers. “The biological sensor can be used to quickly and economically identify hidden rot in potatoes, facilitate better post-harvest management, and reduce food wastage—particularly important given the current global food crisis,” says co-author Dr. Dorin Harpaz.