The nondestructive aspect of single-seed NIR analyzers makes it an attractive device for breeders, according to Dirk Maier, professor and head, department of grain science and industry at Kansas State University.
“When wheat breeders are iterating their varieties, they have very small samples before it goes into production, which is a multiple year cycle,” Maier says. “You don’t want to destroy the kernels within that miniscule sample to do quality analysis so you can preserve the seed for the next generation. If you can run a small sample through this single-kernel NIR, then you can get some quality measurements without destroying the kernel and go on doing the propagation work, saving time, money and the relatively small amount of seed that’s available in those early generations.”
Hurburgh adds to that point: “Generally, when you start to develop a corn hybrid or a soybean variety, your basic stock might fit in a Dixie cup. You’d like that Dixie cup to remain pretty pure. This instrument isn’t going to clean up a truckload, but it’ll clean up a coffee cup.”
Using single-seed analyzers to identify foundation seed in fewer iterations helps bring new varieties to market more quickly.
“This [instrument] is an enabling technology to accelerate plant breeding for whatever aspects the instrument is calibrated — moisture, protein or oil” says Hurburgh. “By isolating seeds that may have what you’re looking for at an early developmental level, you can accelerate the ability to develop higher-quality material. It won’t do it by itself, but it will make the process easier and less expensive.”
Armstrong is currently working with soybean breeders to create a high-oil, high-protein variety; the team uses his single-seed NIR analyzer to sort soybeans that have both the qualities they’re looking for. Those seeds may be genetically different from the rest of the crop, and will be planted to create the next generation of this new optimal-quality variety.
Today, single-seed analyzers improve grain quality through genetics and plant breeding, but there is potential for other applications, including variability and toxin testing.
Different quality attributes can affect how a feedstock should be processed to achieve the desired end product. At an ethanol facility, for example, there may be a wide variability in the starch content of a bulk sample of corn. Armstrong says a processor could use a single-seed analyzer to measure starch variability, allowing the plant to modify its process based on the measurements.
“There are similar theories along the lines of soybean oil extraction,” says Armstrong. “The variability of oil within the beans may affect some of the processes, so rather than looking just at the average oil, you could measure the variability of oil to provide a better indicator of how you can maximize the extraction process.”
The main barrier to using single-kernel analyzers at commercial facilities today is speed. The throughput for wheat on Pearson’s analyzer is about 200 kernels/second, or 20 to 25 kilograms/hour. Armstrong’s NIR analyzers measure a mere three kernels/second. Although it is possible to run parallel systems and double or triple the throughput, the current speed for an individual instrument is not ideal for millers or commercial processors. But over time, as the technology improves, the variability of specific seed components may become routinely measured.
Single-seed analyzers may one day be able to detect mold and toxins, but some voice uncertainty because their presence is measured in the parts/million or even billion.
“That’s probably below the resolution of the instrument, so it may take two to three generations of improvement on the technology before that’s possible,” Hurburgh says. “We’ll probably get there, but it’s a little bit of a stretch simply because the toxins are at very low levels.”
Although toxin presence within a single kernel would be difficult to detect by NIR, it is capable of detecting mold damage and segregating damaged kernels from healthy kernels.