Faster, more comprehensive produce inspection in the works

Scientists with the U.S. Department of Agriculture have developed an optical scanning system to detect contaminants and defects on produce in warehouses across the country. Biophysicist Moon Kim and other researchers published preliminary findings in 2008 and recently received a patent on the updated design.

The system, which uses a camera and two types of light, could become commercially available within the next few years. I spoke with Kim last week. Below are excerpts from our interview.

How does the system work?

This is a light scan imaging system. Light scan [is like the technology used] in a scanner. Our system takes images of agricultural produce moving on a conveyor belt. It captures a line-by-line scan and creates an image. It's taking the light scans at multiple wavelengths. We capture near infrared reflected images, which is reflected light from a near infrared light source. We also take fluorescent images at multiple wavelengths. We combine all that -- and we can accomplish multiple inspection tasks. We're interested in [detecting] animal fecal matter, which is a major source of pathogens.

This improves the detection of contaminants on produce?

Right. And also defects. If produce has cuts or defects, that's the area where pathogens or microbial bugs will attach.

How did you update the previous technology?

One system does it all. Instead of having multiple detection systems, we combine all that into a single light scan imaging device. Our industry uses [imaging] for inspection purposes, but usually that technology is limited to physical sizes or coloration of produce. We are one of the leading research institutes working on the safety issues.

Will the device be used throughout the country?

That's our ultimate goal. This is at the research and development phase, but we have made significant progress. Initially, we tested with round foods, like apples, moving on a conveyor. But it only looked at the top half of it -- a 180-degree view. In order for it to be a thorough inspection system, it has to look at the whole surface. Right now, we're working on a system that will allow us to get the whole surface around fruits and leafy greens.

How fast does the system work?

The speed depends on how industry processes their produce. Also, it's a function of our imaging capabilities. Right now, our goal is about three to four apples per second on a conveyor -- whole-surface inspection. Leafy greens are usually [processed at] 10 feet per second. That's a bit too fast for current technologies, so we are aiming for a conveyor speed of about five feet per second.

Photo, top: Moon Kim with imaging system

Photo, bottom: Schematic illustration of the imaging system

This post was originally published on Smartplanet.com