Sorghum can give antioxidant, gluten-free benefits
June 4, 2010
by Laurie Gorton
Manhattan, Kas. — Sorghum, a cereal grain better known as an animal feed, can be a valuable means for improving health-and-wellness benefits when used in human foods, according to scientists addressing “Sorghum: A whole grain and gluten-free solution,” a seminar jointly sponsored by the United Sorghum Checkoff Program and AIB International.
Describing in-vivo studies with rats, Nancy Turner, Ph.D., associate professor of nutrition at Texas A&M University, College Station, Texas, noted that bioactive compounds may not need to be absorbed to be effective. “Binding to colon cells may have the desired effect alone,” she said. Her research found a reduction in aberrant formations when feeding the bran of brown and black sorghum to rats. She noted that the effect was to speed up the generation of epithelial cells and their subsequent shedding into the fecal stream. “In humans you turn over epithelial cells every three days,” she said. The in-vivo studies also showed an increase in the activity of endogenous protective enzymes in the gut. Similar studies done during the 1980s with wheat bran failed to find such protective effects. She plans to do follow-up studies to isolate the compounds involved and determine the effect of varying doses of these.
Sorghum, a drought-tolerant cereal grain, grows in Kansas, Texas, Nebraska, Oklahoma and South Dakota primarily. Africa is the world’s largest producer of sorghum, but the US ranks No. 3, just behind India and just ahead of Mexico. All sorghum produced in the US is non-GMO and its storage protein, kafirin, is gluten-free. It comes in white, yellow, brown (red) and black forms. The colored varieties contain tannin and their brans are the highest in antioxidant content.
“It often surprises people that the antioxidant levels of the tannin sorghums, measured in ORAC, far exceed any fruit sources,” said Lloyd Rooney, Ph.D., Regents professor and faculty fellow, Department of Soil and Crop Sciences, Texas A&M. “The grain is a treasure trove of bioactive compounds.”
“Sorghum tannins have a unique structure,” observed Joseph Awika, Ph.D., assistant professor of food science and technology, Texas A&M. He observed that although current food use of sorghum is relatively limited in the US, the grain has huge potential.
Tim Carr, professor of nutrition and health sciences, University of Nebraska at Lincoln, and two of the department’s doctoral candidates discussed health benefits from the lipids in sorghum, which include potential for lowering “bad” cholesterol levels. Scott Bean, Ph.D., and Jeff Wilson, Ph.D., from the Center for Grain and Animal Health Research (CGAHR) of the U.S. Department of Agriculture’s Agricultural Research Service, Manhattan, KS, examined the functionality and digestibility of sorghum starch and proteins, while Yong-cheng Shi, Ph.D., Mark Haub, Ph.D., and Fadi Aramouni, Ph.D., all of Kansas State University, Manhattan, Kas., covered resistant starch, glycemic index testing, milling and flour quality matters involving sorghum.
On the second day, the program turned to the practicalities of making baked foods with sorghum flour. Sue Ruan, a Kansas State University graduate student, detailed how a “master mix” made with sorghum can facilitate preparation of gluten-free and whole grain foods. Brook Carson, technical product manager at ADM Milling, Shawnee Mission, Kas., covered applications of sorghum in gluten-free foods. Brian Strouts, head of experimental baking at AIB International, directed a hands-on session allowing attendees to make gluten-free chocolate-chip cookies with sorghum flour and other gluten-replacement ingredients.
Throughout the two-day meeting, the 60-plus seminar participants sampled an ample supply of sorghum-containing baked foods including cookies, muffins, breakfast cereals and breads prepared by the Nebraska Sorghum Board and graduate students at Texas A&M. Many were gluten-free products.