Putting Kernels to the Test

K-State Wheat Quality Lab boosts milling and baking quality of up-and-coming varieties 1,000 grams at a time.

The journey from a potential genetic cross to the latest released wheat variety requires years of testing by public and private wheat breeders. They keep their eye on every aspect of agronomic performance from disease resistance to standability. Equally important is the partnership between wheat breeders and the Wheat Quality Lab at Kansas State University. Researchers at the lab help streamline the wheat breeding process by ensuring only lines with acceptable or superior milling and baking performance become the varieties Kansas wheat producers eventually plant and harvest. 

“Agronomic performance and end-use quality are both critically important when selecting wheat varieties for commercial production,” said Aaron Harries, Kansas Wheat vice president of research and operations. “Supported by the two-penny-per-bushel wheat checkoff, the Kansas Wheat Quality Lab provides breeders, researchers and producers with the information they need to select which wheat lines to advance and which varieties to grow.”

Breeders like Guorong Zhang, K-State wheat breeder based at the K-State Agricultural Research Center in Hays, create about 800 new experimental lines each year - the critical step in a decade-long research process.  However, not all of these lines have acceptable flour and baking qualities. Early sorting of which lines do or do not meet those standards saves time and cost for further testing down the road. 

“Quality is an important trait for breeders; we don’t want to release a variety with poor quality,” Zhang said. “Thanks to the lab, they can evaluate all our advanced breeding lines. Based on the lab testing, we can see the lines with poor quality, and we will not continue those lines.”

The Kansas Wheat Quality Lab annually tests 350 to 400 advanced lines from the K-State wheat breeding programs. It takes until year five in the breeding program to have enough seed to run preliminary quality tests like protein content and mixograph. But, as lines go through more field testing, more seeds are harvested from each line, allowing for more extensive quality evaluations. 

“Breeders can select for factors that determine agronomic performance, but milling and baking performance has to be tested in the lab,” said Yonghui Li, director of the Wheat Quality Lab. “These tests require specialized equipment along with training and experience to determine milling and baking quality.”

A sample consists of 1,000 grams of wheat. The lab first looks at the sample using near-infrared (NIR) spectroscopy technology. These tests allow researchers to examine protein quantity and test the moisture content of the grain. 

Researchers then temper the grain - or add a little bit of water to help make the milling process easier. Then, the sample is milled to separate the bran - the external coating of the wheat kernel - from the endosperm - the white part of the wheat kernel that becomes white flour. This resulting flour sample is tested too - looking at color and how much flour can be produced from the sample - the higher the amount, the better for millers. 

The testing then progresses to looking at protein quantity and quality and dough properties. Tests like the mixograph and farinograph determine dough-mixing properties like water absorbance, mixing stability and more. 

The final step is to take the flour, add water, yeast, sugar and salt and bake a pup loaf of bread, following standard protocols. Researchers then examine the quality of that bread - from the volume of the loaf to the crumb. 

The combined results of these tests are given back to K-State wheat breeders, who use the information to help determine which lines to advance in their breeding programs. The milling and baking tests are repeated each year as lines are in the advanced stages of the program, meaning by the time a variety is released, breeders have four to five years of quality data available. 

In addition to experimental lines, the lab tests 30 to 40 samples each year as a final evaluation before they are released by public and private wheat breeders throughout the Great Plains. The results are submitted back to the Wheat Quality Council, which compiles the results into an annual report. 

The main funding for the lab’s operations - necessary equipment maintenance along with a full-time staff member and a team of undergraduate student workers - comes from the Kansas wheat checkoff. In turn, the lab helps support the reputation of Kansas wheat as having high-quality wheat, creating more opportunities in domestic and international markets. 

“With those checkoff dollars, we can evaluate quality each year and work with our breeders to create those best-performing varieties for Kansas,” Li said. “In turn, when producers choose varieties with better end-use quality, it improves the overall quality and marketability of Kansas wheat.” 

Learn more about the K-State Wheat Quality Lab at https://www.grains.k-state.edu/facilities/wheatqualitylab/. 

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Written by Julia Debes for Kansas Wheat