It’s all about mirrors | Two optical technologies sort out problems in plants and animals
PINAWA, Man. — A new infrared device uses mirrors to identify a wide range of harmful bacteria in plants and animals.
Another new optical invention is designed to identify and delete fusarium and ergot kernels from grain shipments.
Both inventions may have far-reaching health and economic implications for identifying and isolating bacteria that downgrade or endanger agricultural products.
Both technologies are the product of Winnipeg-born physicist, David Prystupa, working in a small, rented basement lab at the Atomic Energy of Canada facility near Pinawa.
Prystupa is president and chief scientific officer of Spectrum Agricultural, a research and development company he formed to explore new ways to use optical technology to improve the quality, safety economics of food production.
Prystupa is a one-man band of scientific innovation. Not only does he run the business side of things by himself while nudging at the leading edge of physics and optics, but he also does his own machining, builds his own prototypes, organizes field demonstrations and changes burned out light bulbs.
Graduate students still perform many of his research’s replicated trials.
Prystupa works on nearly 20 projects dealing with optical detection within the food and agriculture industry.
Two of the projects are almost ready for commercialization.
Prystupa feels that one of them, infrared bacteria detection, will have a large impact on overall global human health and the long-term economic challenge to farmers feeding an increasing population.
In scientific circles it’s known as single bacterium spectroscopy (SBS), but within the confines of his lab he jokingly calls it the chicken machine because it’s his first working version of the new technology and it just happens to be intended to find bone fragments in processed chicken products.
The object of SBS is to achieve immediate sensitivity to a previously identified, unwanted single cell within a tissue sample.
Prystupa’s system eliminates the need for conventional, time-wasting cultural methods that take hours or days and goes far beyond detecting bone fragments.
It means municipal hospitals, grocery stores, vet clinics, food processing plants, bakeries, grain elevators or even a school nurse could identify and confirm the presence of a specific bacteria or foreign substance in a tissue sample within a matter of minutes.
“It’s an optical system I designed to inspect food samples at the production line rate of 200 birds per minute,” he said.
“It isolates any defects or bone fragments down to one-third of one millimetre. The frequency of these defects is only one in one million, but when they come down the line, the chicken machine finds all of them.
From industry’s point of view, it eliminates having to deal with the lawyers for the family of the deceased. For the consumer, of course, it will eliminate the fear of these incidents happening in the first place.”
The commercialized product will be a hand-held gun that an inspector can aim at or press against food coming down the production line.
Prystupa said he is ready to find a partner to bring the product to market, adding he has already demonstrated that it works through typical plastics used in food wrapping.
The device carefully aims a narrow infrared beam at a tissue sample mounted on a polished aluminum mirror in the centre of an arrangement of more mirrors.
The target mirror in the centre, plus all surrounding mirrors, are capable of minute adjustments so the infrared beam will pass through the same tiny target point in a cell three times, thus pushing more useful data through the detector and on to analytical processors.
A single infrared pass through a target cell will not yield enough information with many types of animal and plant bacterial diseases.
Prystupa said his arrangement of six mirrors gives the detector three hits, which provides enough data for the program to make decisive judgments.
More mirrors can be added for more advanced readings.
“This same technology on a larger scale will process 25,000 individual cells at one time in the mid-IR range.”
The accumulation data can have a tremendous impact on worldwide food production and food integrity.
The other device, which Prystupa calls the grain machine, is engineered to optically check every grain kernel in a lot, even large volume shipments loaded on trains and ships. The official name of the machine is K-max.
The discovery of an abnormal kernel triggers an electronic pulse that causes a small aluminum leg to remove the kernel from the main grain flow and put it into a separate cull bin.
Each leg is capable of ejecting 100 infected kernels per second.
In his early tests, Prystupa re-ported to Agriculture Canada’s Cereal Research Centre in Winnipeg and the Canadian Grain Commission that the new technology did a good job of identifying diseased kernels.
“The reaction I got from them was that maybe I just got lucky,” he said.
“So they gave me 27 wheat cultivars to test and we got the same positive identification results, enough to satisfy their scientific requirements.”
Unlike high-cost, high-tech colour separators, Prystupa’s grain machine depends on readily available, off-the-shelf light sensors that cost less than $1 each. These inexpensive sensors are arranged on a circuit board so they can identify diseased grain kernels passing in front of them.
It might seem that such highly singulated technology is only for seed growers and dealers processing small grain quantities for special contract, but Prystupa said it is actually a high volume machine.
Conventional colour sorters handle 100 kernels per second, but Prystupa’s first working prototype handles 120 kernels or more per second.
“We have run experiments as high as 20,000 kernels of wheat per second with this optical system, but that’s in a controlled lab setting,” he said. “Theoretically, the optics themselves can do a billion kernels per second, but there’s no way to ever handle singulated grain that quickly. In reality, I think we can get up to 2,000 kernels per second once we figure out how to handle that volume. Keep in mind this should not be confused with color sorting technology. This is a totally different process.”
In its basic low-cost form, the grain machine can identify and remove 93.5 percent of fusarium tainted wheat kernels. The basic apparatus employs 32 light sensors costing 97 cents each.
The machine’s fusarium sensitivity can be improved to 95 percent without sacrificing good grain by fitting it with more sensitive infrared sensors that cost $27 each.
However, even with the more expensive infrared sensors, five percent of the tainted kernels still end up in the clean bin.
Prystupa said it’s difficult to justify spending the extra money for a gain of only one and a half percent.
The device can be improved to 100 percent without spending extra money, but trade-offs in speed and efficiency have to be made.
Five-year averages from the grain commission show that four million tonnes of wheat a year lose one or more grades because of fusarium, he said.
Most of that grain drops from No. 1 to No. 2 or No. 3. The grain can regain $10 to $12 per tonne in value when fusarium is removed.
Fusarium can be removed at a cost of $5 per tonne, putting $5 to $7 back into the sellers’ pockets.
One of Prystupa’s grain machines is now a working prototype, mounted on a trailer and ready to analyze 400,000 bushels of fusarium and ergot tainted durum, spring or winter wheat this year.
“I need B-trains of (feed) grain, lots of them,” said Prystupa, who is seeking farmers’ grain for testing.
“The prototype runs at one tonne per hour and it’s ready to go right now. When we build mobile commercial truck units or trailer units, they’ll run at 18 tonnes per hour.”
He said the technology will work in the same way to remove stained and otherwise unsuitable barley from a malt sample.
For full-scale elevator operations, 100 pound grain machines the size of his prototype will be stacked five or six high to meet the throughput requirements.
He is building enough of these individual units to equip a small number of elevators if the demand is there. They can also be mounted for mobile cleaning units.
Prystupa said traditional sorting methods with screens and gravity are 40 percent effective. High-end optical devices that measure colour are more than 90 percent effective, but their $400,000 price tag is a major hurdle.
Prystupa thinks his grain machine should sell for about half the price of the high-end optical sorter.
For more information, contact David Prystupa at 204-753-8229 or 204-753-2311 #62546 or visit www.spcsci.ca.