A New Hope
by Laurie Gorton, Baking & Snack
Resilient, moist crumb in a gluten-free bread? Sure, if you make it with sorghum flour, as Sarah Boswell, a PhD candidate at Texas A&M University, did to demonstrate this application to attendees at the United Sorghum Checkoff Program (USCP) seminar in early June. Held at the facility of its co-sponsor, AIB International, Manhattan, KS, the seminar dug into sorghum’s scientific, nutritional, functional and technical properties.
Sorghum, a cereal grain better known in the US as an animal feed, can be a valuable means for improving healthand-wellness benefits when used in human foods, according to seminar speakers. Research found positive in-vivo connections between the antioxidants in red and black sorghum bran and reduction of the risk of certain cancers, according to scientists at Texas A&M University, College Station, TX, while prebiotic effects were noted by researchers at University of Nebraska (UNL), Lincoln, NE. Experts from Kansas State University (KSU), Manhattan, and the Center for Grain and Animal Health Research (CGAHR), also located at Manhattan and part of the Agricultural Research Service of the US Department of Agriculture, reported on the functionality and digestibility of sorghum starches and proteins. (A database detailing sorghum research is available at USCP’s Web site, www.sorghumcheckoff.com.)
Sorghum, a drought-tolerant cereal grain, grows primarily in Kansas, Texas, Nebraska, Oklahoma and South Dakota. Africa is the world’s largest producer of sorghum, but the US ranks No. 3, just behind India and just ahead of Mexico. Sorghum comes in white, yellow, brown (red) and black colors, and its storage protein, kafirin, is gluten-free. All USproduced commercial sorghum of any color has no tannins and is non-GMO. Specialty sorghums with high antioxidants do have tannins and are usually dark in color. All colored sorghums, including those commercially grown, are very high in polyphenols such as those found in colored fruits.
The US is one of the few sorghum-producing countries where food uses are minor, at best. Globally, its primary use is for human foods. These applications include thick porridges, popped sorghum, fermented and unfermented flatbreads, cooked and served as a whole grain, malted into both alcoholic and non-alcoholic beverages, hard cookies, tortillas and, in some cases, extruded commercial products.
The really exciting health-and-wellness news is coming out of Texas A&M, where sorghum’s cancer-fighting antioxidant properties are being studied in-vivo with rats. Nancy Turner, PhD, associate professor of nutrition at Texas A&M, 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 observed that the effect was to speed up the generation of epithelial cells and their subsequent shedding into the fecal stream. “Humans 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.
“It often surprises people that the antioxidant levels of the tannin sorghums, measured in ORAC, far exceed any fruit sources,” said Lloyd Rooney, PhD, Texas A&M Regents professor and faculty fellow. “The grain is a treasure trove of bioactive compounds.”
“Sorghum tannins have a unique structure,” observed Joseph Awika, PhD, assistant professor of food science and technology at Texas A&M. He said that while current food use of sorghum is relatively limited in the US, the grain has huge potential.
Tim Carr, professor of nutrition and health sciences at UNL, and two of the department’s doctoral candidates discussed health benefits from the lipids in sorghum, which include potential for lowering “bad” cholesterol levels. CGAHR’s Scott Bean, PhD, and Jeff Wilson, PhD, examined the functionality and digestibility of sorghum starch and proteins, while Yong-cheng Shi, PhD, Mark Haub, PhD, and Fadi Aramouni, PhD, all of KSU, 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 KSU graduate student, detailed how a “master mix” made with sorghum flour can facilitate preparation of gluten-free and whole-grain foods. Brook Carson, technical product manager at ADM Milling, Overland Park, KS, covered applications of sorghum in gluten-free foods. Brian Strouts, head of experimental baking at AIB International, directed a handson session allowing attendees to make gluten-free chocolate-chip cookies with sorghum flour and other glutenreplacement ingredients.
Throughout the 2-day meeting, the 60-plus seminar participants sampled an ample supply of sorghum-containing baked foods including cookies, muffi ns, breakfast cereals and breads prepared by the Nebraska Sorghum Board and graduate students at Texas A&M. Many were gluten-free products.
Consumers usually compare glutenfree products to mainstream standards, according to Ms. Carson. “McDonald’s doesn’t have a [gluten-free hamburger meal] because they feel they can’t get a good gluten-free bun,” she stated, although she noted Burger King is offering a “gluten sensitive menu.”
Sorghum is, by nature, gluten-free. More economically priced than specialty starches and competitive with other flours in cost, sorghum flour made from white sorghum provides neutral flavor and color and can be considered an “ancient grain” suitable for multi- and whole-grain products. ADM Milling is a commercial producer of white sorghum flour, milling it at the company’s Plainview, TX, facility.
By the way, Ms. Boswell, a lifelong celiac, is not done with her development of the gluten-free bread. “I want to look at improving the flavor profile,” she told Baking & Snack. She and her classmates plan to enter the sorghumbased bread in the Institute of Food Technologists Student Association’s new product competition at IFT’s annual meeting later this month.