Novel dough formulation leads to soy-based bread.

Soy products are consumed regularly--at least once a week--by 28% of Americans. With soy-based foods such as soy burgers, soymilk, and soy protein bars increasing in popularity, we are expanding our consumption of many different soy products across the board. Many of us have come to realize that soybean oil (vegetable oil) along with olive oil are the healthiest among cooking oils. In addition, there are indications that eating soy-based foods may play a role in reducing obesity.

In the past, a musty, "beany" taste has kept consumers from liking soy-based breads. But USDA-ARS scientists have come up with a new dough formulation that may change their minds. The bread-making research is part of an effort to develop new, value-added uses for corn, soybeans, wheat and other crops at the ARS National Center for Agricultural Utilization Research. There, investigators determined how to use soy flour to enrich the protein content of bread while minimizing its beany aftertaste, a feat that's eluded technologists since the 1970s.

The scientists prepared dough formulations containing five different ratios of defatted soy flour, whole and white-wheat flour. They added different amounts of ascorbic acid, sugar, salt, milk, water and vegetable shortening to the doughs as well as active dry yeast to leaven them.

After baking the bread, the researchers analyzed the taste and texture, observing that the yeast, extra sugar and ascorbic acid significantly reduced the soy's beany aftertaste. The three ingredients also enabled the investigators to produce loaves containing 30% to 40% soy flour and 112 grams to 127 grams of protein, compared to 65 grams found in all-wheat bread.

Trained panelists at Kansas State University's Sensory Analysis Center, who evaluated the breads, found them comparable to all-wheat bread. Although the soy-based breads were slightly more dense, health-conscious consumers aren't likely to find the texture much different than that found in multi-grain and other specialty breads, we're told.

Besides grocery store shelves, the soy-wheat bread could prove especially welcome at local food assistance programs. Costing about 50 cents a loaf, the bread meets the recommended daily values of protein, fat and carbohydrates. Plus, it is high in total dietary fiber and such heart-healthy compounds as isoflavones. The bread is easily prepared with standard bread-processing equipment.

Researchers recently published the soy bread work in the Journal of Food Science, 68(6), pp. 2141-2145. They did not patent the process, so it is available for anyone to use. The concept should appeal to many interested in the health benefits of soy.

Further information. Randal Shogren, USDA-ARS National Center for Agricultural Utilization Research, Plant Polymer Research, Room 2110A, 1815 N. University St., Peoria, IL 61604; phone: [phone]; fax: [phone]; email: [e-mail].