One bad apple may not spoil the whole bunch, but when it comes to distributing food, a lot
of good goes out with the bad.Now, researchers from Princeton University and Microsoft Re
search have developed a fast and accurate way to determine fruit quality, piece by piece,
using high-frequency wireless technology. The new tool gives suppliers a way to sort fruit
based on fine-grained ripeness measurements. It promises to help cut food waste by optimi
zing distribution: good fruit picked from bad bunches, ripe fruit moved to the front of th
e line.Current methods to determine ripeness are either unreliable, overly broad, too time
-consuming or too expensive to implement at large scales, according to the new study, whic
h was presented earlier this week and won Best Paper at 2023 ACM MobiCom, the flagship con
ference on networking and mobile computing. “There is no systematic way of determining the
ripeness status of fruits and vegetables," said Yasaman Ghasempour, assistant professor o
f electrical and computer engineering at Princeton and one of the study’s principal invest
igators. “It is mostly random visual inspection, where you check one fruit out of the box
on distribution lines and estimate its quality through physical contact or color change."B
ut this kind of visual inspection leads to poor estimates much of the time, she said. Rath
er than rely on how the peel looks or how it feels to the touch, advanced wireless signals
can effectively peek under the surface of a piece of fruit and reveal richer information
about its quality.