The current falling number test, developed almost 70 years ago, is slow, expensive, exhibits high variability and most importantly, does not assess alpha-amylase levels directly. The technology is poorly utilized because it requires large, specialized equipment, laboratory conditions and experienced operators. The process requires taking a wheat meal sample, mixing it with water, then putting that mixture on a falling number instrument that heats water to boiling.
“You essentially make a gravy or slurry,” said Dr. Amber Hauvermale, a research assistant professor in WSU’s Department of Crop and Soil Sciences and lead on the grant. “Then you drop a plunger into the gravy and count, in seconds, how long it takes for the plunger to fall to the bottom. That number is the falling number. Samples with high levels of alpha-amylase, which is bad for baking, have much lower falling numbers.”
In the wheat industry, prices are discounted when falling numbers go below 300 seconds. In 2016 alone, low falling numbers cost the grain industry over $30 million.
“Low falling number events were once seen every 10 years or so, but now they are happening more regularly, with some regions seeing events every two to four years,” Hauvermale said.
Due to expense and logistics, most grain elevators don’t have a falling number testing system on hand. That means wheat is mixed at the elevators, and problems are found much further down the supply chain. Containers with wheat combined from many growers may get hit with a bad test result, reducing everyone’s profits.
“We need a better test that can be used in real time at elevators to help separate loads of wheat that have low falling numbers,” Hauvermale said. “That reduces grower discounts, ensures customers get the best quality grain available and consumers get high-quality end products like cakes and bread.”
To develop the tests at an industrial scale, the research team is working with EnviroLogix, a company specializing in rapid tests for the grain industry.
In addition to developing new rapid tests, the grant also includes two other important components to help growers manage alpha-amylase. The first is developing an early warning system to alert grain handlers to weather patterns likely to cause spikes in alpha-amylase. The second is conducting research for a better understanding of the genetic regulation of alpha-amylase. This will provide breeders with tools for breeding wheat varieties that are less susceptible to low falling numbers.