SensNews June 2020

Sensor100 2020 24 The LastWord A few years ago,The LastWord was a regular feature of Sensor100 which included bizarre, off-topic and other amusing items which didn't fit anywhere else. The pandemic lockdown provides an opportunity to re-introduce this feature from time to time. New Electronic Nose Sniffs Out Perfectly Ripe Peaches for Harvest To help with harvesting, scientists have been developing electronic noses for sniffing out the ripest and most succulent peaches. In a recent study, one such e-nose exceeds 98 percent accuracy. Sergio Luiz Stevan Jr. and colleagues at Federal University of Technolo- gy - Paraná and State University of Ponta Grossa, in Brazil, developed the new e-nose system. Stevan notes that even within a single, large orchard, fruit on one tree may ripen at different times than fruit on another tree, thanks to mi- croclimates of varying ventilation, rain, soil, and other factors. Farm- ers can inspect the fruit and make their best guess at the prime time to harvest, but risk losing money if they choose incorrectly. The e-nose system created by his team has a set of gas sensors sensitive to particular VOCs. The measurements are digitized and pre-processed in a microcontroller. Next, a pattern recognition algorithm is used to classify each unique combination of VOC mol- ecules associated with three stages of peach ripening (immature, ripe, over-ripe). The data is stored internally on an SD memory card and transmitted via Bluetooth or USB to a computer for analysis. IEEE Spectrum 1 2 June