Inulin, brown sorghum bran, flaxseed improve gluten-free bread.

Gluten-free breads often are of poor quality and are low in health-promoting compounds such as dietary fiber, antioxidants and omega-3 fatty acids. Inulin, brown sorghum bran and flax are good sources of these compounds. People with a very severe genetic intolerance to gluten have celiac disease. Our growing awareness of celiac disease will result in an increased diagnosis rate of the illness and more demand for better-quality gluten-free breads.

Scientists at Texas A&M University wanted to improve the quality and nutritional content of gluten-free bread by substituting inulin, brown sorghum bran and flaxseed for a percentage of the composite flour in the bread. While adding dietary fiber to wheat-based breads generally decreases their quality, the researchers show that additional dietary fiber can improve both the nutritional content and quality of gluten-free breads.

In experiments, the researchers substituted inulin, brown sorghum bran and flaxseed in bread individually at 5% and 10% concentrations and in 50-50 combinations. A control bread contained no inulin, sorghum bran or flax. A gluten-free batter was mixed with a stand mixer, scaled into pans, proofed and baked with steam. The composite flour was composed of 30% sorghum flour, 30% tapioca flour, 30% cornstarch and 10% potato starch. The flour also included water, eggs, margarine, sugar, honey, non-fat dry milk, yeast, xanthan gum, gelatin, salt and vinegar.

Investigators evaluated the bread based on its specific volume, crumb firmness, color, moisture, flavor and nutritional content. At 10% substitution levels, inulin increased specific volume and decreased crumb firmness over all of the treatments and the control. The addition of 2.5% flax and 2.5% sorghum bran to the 10% inulin formula did not significantly reduce specific volume or increase crumb firmness.

This formula provided more than 6 g of dietary fiber per 56 g-slice, as well as 323 mg of omega-3 fatty acids and 2113 [micro]g of antioxidant activity. While high doses of inulin may cause gastrointestinal discomfort, the amount in a slice of bread in this research was well-tolerated.

Further information. Lloyd W. Rooney, Department of Soil and Crop Sciences, Texas A&M University, 370 Olsen Blvd., Heep Center, Room 429, College Station, TX 77843; phone: [phone]; email: [e-mail].