Low-phytate wheats may improve nutrition, offer better dough-mixing qualities.

Newly developed lines of wheat--with one-third less phytate than current varieties and up to three times more phosphorus in the flour made from the wheat--are being developed by breeders. They promise to offer better nutrition, both as feed for livestock and in breads and other wheat-based foods for consumers.

USDA-ARS plant geneticists and colleagues at the University of Idaho Research and Extension Center, Aberdeen, ID, have studied the effects of low-phytate wheat lines on the baking qualities of the flour made from them. They found no adverse impact on hard wheat, but some ill effects on soft wheat.

Phytate contains phosphorus in a less digestible form, which creates less nutrition for people and animals, and much more polluting phosphorus excretions from livestock. Low phytate levels help people absorb not only more phosphorus, but also zinc, manganese and iron from whole-grain products, thus increasing their nutritional benefits. These and other minerals are naturally present in wheat kernels.

The ARS-University of Idaho study showed that low-phytate hard wheats might have better dough-mixing qualities for bread making. However, scientists need to conduct additional tests to confirm the effects of low phytate on soft wheat, which appeared to increase the flour's ability to absorb water. The researchers undertook their tests on two classes of hard wheat and a premium class of soft wheat.

The scientists also tested the agronomic performance of low-phytate wheats grown for two seasons in field studies. The lines sometimes had lower yields and smaller kernels. The inconsistent yields suggested the problem was minor, with enough genetic variation to solve through plant breeding.

The scientists tell us that they are not so much concerned about the need for additional tests, but rather have a desire to have their finding confirmed by other scientists or by themselves. The current results were unexpected--pleasant but still unexpected. The researchers conducted enough trials to believe that their findings have merit and should be investigated further.

Giving too much phosphorus to wheat and barley plants increases the amount stored as phytate, rather than as more digestible forms of phosphorus. Not only is the phosphorus in low-phytate grain crops more digestible, but low-phytate rice grains with less phytic acid could mean improved nutrition for the world's malnourished. The human body rarely lacks phosphorus, but people in developing nations with primarily grain-based diets sometimes have mineral deficiencies.

Further information. Edward Souza, USDA-ARS Soft Wheat Quality Research, The Ohio State University, Williams Hall, 1680 Madison Ave., Wooster, OH 44691; phone: 330-263-3891; fax: 330-263-2561; email: souza.6@osu.edu.