Distillers Dried Grain Yields High-Fiber, High-Protein Flour

A flour made from distillers dried grains used in the flat bread being baked at the food science lab at South Dakota State University. The flour could be a solution to global hunger.
By PADMANABAN KRISHNAN | December 09, 2009
Sowmya Arra is known around the lab for her soft-spoken and friendly nature, but the South Dakota State University food science graduate student has big dreams. Arra's goal is to feed the world through a low-cost yet sustainable means using distillers dried grains (DDGs).

While that may seem like a tall order, Arra is well on the way to reaching her goal after winning the graduate research poster competition at the Institute for Food Technologists Conference in Anaheim, Calif. Competing against 50 other graduate students, Arra won a $1,000 cash award and certificate for her project, "Fortifying Chapathies, an Asian Whole Wheat Unleavened Flat Bread. Using Corn Distillers Dried Grains."

Since the competition in July, Arra's research has expanded to include naanoven-baked, leavened flat bread popular in Afghanistan, India and Pakistan and which tastes remarkably like pizza crust.
When choosing her thesis project, Arra, who is from India, said she wanted "to make a product that has all the nutrient values." She found that in food-grade, DDGs, which contain 40 percent dietary fiber and 36 percent protein.

"Due to economics and their culture, many people make their own bread," Arra explained. "Since they make flat bread, it only makes sense to provide a better flour ingredient, which has higher nutritional qualities."

Developing food products from DDGs has been a challenge I have faced as Arra's adviser since I came to SDSU in 1989. The food grade DDG is a product I have been working on at SDSU for the past 20 years and I envision limitless possibilities for the flour made from DDGs.

One case where bland is best
In order to blend with flour, the DDG flour has to be made aroma neutral, taste neutral and texture neutral. What needs to be created is in essence, a stealth ingredient that blends with the background and allows other ingredients to pick up the slack. This ingredient must also work in harmony with the food system.

So far, that food system can handle about 7 percent to 20 percent of the DDG flour in the traditional flour used in bread products. Adding any more of the DDG flour, particularly in yeast-leavened products, undermines the dough system. By replacing more then 20 percent of wheat flour with the DDG flour, one risks baking "hockey pucks" or "bricks," but flat breads are a different story. Mixed in at the right levels, the DDG flour will add significantly to the fiber and protein of tortillas, cookies, noodles and breads.

Next step belongs to industry
A variety of entities have invested in the research so far. At one time or another in the process, that funding has come from the U.S. Agricultural Research Service, the SDSU Agricultural Experiment Station, the South Dakota Wheat Commission and the South Dakota Corn Utilization Council.

At this point, the team has taken the DDG flour about as far as it can. The entrepreneur is the one who will have to run with it.

Finding those entrepreneurs in a down economy may prove to be difficult. One person who's on the lookout is Kurt Rosentrater, a biomass engineer with the Agricultural Research Service, whose mandate from USDA is to add value to DDGs. Rosentrater has worked collaboratively with SDSU for the past five years.

Closely associated with the research that resulted in Arra's master's thesis, Rosentrater said he has fielded calls from "dozens" of companies that are toying with the idea of pursuing the project. "It's got to be industry's investment," Rosentrater said. "So far, nobody's been willing to pull the trigger and take that leap."

Capturing what could be an international market will start first with the U.S. Food and Drug Administration. Rosentrater said that the FDA will need to ensure that the corn is food-grade from the kernel to the finished product. For some ethanol plants, that may mean the installation of new equipment.

Time may be right for DDG flour
The federal call for a significant increase in renewable fuels by 2022 will also mean an increase in the production of DDGs. According to Rosentrater, about 80 percent of DDGs is used as feed for beef and dairy animals with the rest going to feed swine and poultry.

"We have not hit a point where we've saturated that market," Rosentrater said, though he does note some interesting factors that may influence the market.

Rosentrater estimates ethanol plants are currently producing between 25 million metric tons and 30 million metric tons of DDGs and the new fuel standards may increase that output to as much as 40 million metric tons.

He said that about 20 percent of U.S. DDGs was exported internationally last year. "That's up considerably," Rosentrater said. "There are plenty of opportunities if the ethanol plants are interested."
This work has accomplished much to add value to an underutilized co-product. The research has always intended to get everything out of the corn, including the squeal.

At present, DDGs are sold at 8 to 10 cents per pound, $165 per ton, as livestock feed. Food ingredients are sold at about $2 to $3 per pound. Adding utility in the food industry will enhance DDGs' economic return to the producer.

We have demonstrated scientific, nutritional and technical merit, but we realize that it is the economic drivers that will permit food-grade DDGs to take wing. The world is hungry for novel protein, fiber and functional ingredients if the $21.8 billion nutraceutical ingredients market is any indication.

Far from just a "byproduct" of the ethanol-making process, DDG can account for 20 percent to 40 percent of an ethanol plant's income. Adding value to the dried distillers grain makes business sense while at the same time helping to alleviate world hunger. EP

Padmanaban (Padu) Krishnan is a food scientist South Dakota State University. Reach him at padmanaban.krishnan@sdstate.edu.