The US-based Agricultural Research Services has devised a method of detecting fecal bacteria in fresh produce, which it claimed could reduce the chances of contamination to zero.
Yud-Ren Chen, an agricultural engineer with the Agricultural Research Service's Instrumentation and Sensing Laboratory in Beltsville, Maryland, is leading a group to develop "machine-vision" systems to detect contaminationthe human eye cannot see. The system is aimed at preventing Escherichia coli O157:H7 from tainting apple cider and juices made from apples and other fruits. This particular strain of E. coli infects people who drink contaminated, unpasteurised cider or juices.
Chen is starting with apples, but he expects the system to work with all fruits and fresh produce. His on-line system will eventually direct a camera to take three spectral images of each apple through different colour filters. A computer would then analyse the spectral images to detect the telltale signatures of fecal contamination or fly specks, as well as of fungi, rot or other diseases.
One of Chen's team members, biophysicist Moon Kim, brought his expertise in remote sensing of vegetation to ARS from the National Aeronautics and Space Administration. To detect fecal contamination, he is sensing photosynthetic pigments from plants, a turnaround from sensors aboard airplanes or satellites.
Apple packinghouses currently have automated ways of sorting for sizes and colours. When Chen's system is commercialised, it would likely be merged withthose sorting systems, as well as with others in the pipeline.
ARS is the US Department of Agriculture's chief scientific research agency.