Hard Oats Stand the Test

Plant breeders can identify oat varieties that turn out a good measure of nutritious oatmeal with an instrument that Agricultural Research Service scientists invented several years for a different purpose: to classify wheat as hard or soft.

Called a single kernel hardness analyzer, the instrument reveals whether oats are hard or soft. If the oats are hard, they can be dehulled with less likelihood their insides--known as groats--will break in the process, according to findings by scientists at the ARS Cereal Crops Research Laboratory in Fargo, N.D.

Fewer broken groats mean more and bigger flakes of rolled oats and fewer siftings channeled into less valuable animal feed.

The single kernel hardness analyzer was invented at ARS' U.S. Grain Marketing and Production Research Center in Manhattan, Kan. ARS patented (#5,005,774) the invention in 1991.

The analyzer was one of three hardness instruments that the Fargo scientists used for their oat study. It weighs one kernel at a time, then crushes it to gather measurements of moisture, hardness and size.

In recent experiments with six genetically diverse oat cultivars, the scientists first dehulled identical samples using a high-pressure air stream that blows kernels against a corrugated metal wall. Then they tested hardness of each sample and found that the harder kernels generated fewer broken groats. Also, when moisture levels remained above 8 percent during dehulling, fewer groats broke during dehulling.

In addition, the scientists found that the oat cultivars that produced fewer numbers of broken groats also had higher levels of beta-glucan. Beta-glucan has been shown to decrease blood serum cholesterol levels.

Next the scientists will confirm whether the relationship between hardness and beta glucan content holds true with more oat varieties grown in diverse environments. If so, plant breeders could more easily breed the two traits at the same time.

Scientific contact: Douglas C. Doehlert, ARS Cereal Crops Research, Fargo, N.D., phone (701) 239-1413, fax (701) 239-1377, doehlert@plains.nodak.edu.