The team at USDA-ARS developed the soft durum variety by altering the gene chromosomes in the kernel through non-GMO methods.
USDA-ARS director Dr. Craig Morris said the work took a number of years.
“It’s by no means a trivial lab exercise,” he told attendees at the AACCI’s annual meeting in Providence, Rhode Island earlier this month. “…Wheat is as genetically diverse as all of us sitting in this room and we need to take that genetic variation into mind.”
The reason durum wheat was so hard, he said, was because the grain lacked puroindolines – molecular genes that heavily influenced texture and hardness in wheat grains.
“I asked myself, can we repair this? Can we go back and make the durum soft as it perhaps should have been originally? The answer is absolutely yes.”
Morris and his team moved the puroindolines – located on small chromosomes in wheat – into hard durum wheat. “And low and behold we have a soft endosperm,” he said.
Soft wheat, loose starch
Morris said the softness of wheat kernels had a “profound influence” on the milling and baking quality of grains.
The texture and size of flour milled was different, he said, but it could still be milled through regular hard durum mills.
“The hallmark of soft wheat is that the starch granules are fairly loose in the endosperm matrix,” he explained.
That transpired, in some cases, to better baking, he said. For cookies – the soft durum gave better baking rise and for pancakes and chapattis it carried through a warm, yellow color – typically appreciated in pasta and spaghetti.
The USDA-ARS team also ran tests on 100 g bread loaves but found the soft grain didn’t bake the same quality product compared to its hard spring wheat counterpart.
Future research into gluten strengthening
The team was therefore currently working on further research, Morris said – looking at moving glutenin genes into the soft durum grain. This, he said, should improve dough and gluten strength when baking.
“We’re actually trying to put more oomph into soft durum to see how much we can ramp up the gluten strength.”