They might be called a blessing or a curse -- tannins, which are present in certain sorghums, contain health-promoting antioxidant properties, but also provide a bitter taste and decreased protein digestibility.
To better understand tannins, their role in sorghum and how they can be altered to improve sorghum's use as food and feed, a team of scientists led by Kansas State University and U.S. Department of Agriculture researchers, has cloned the tannin gene in sorghum.
Tannins' high antioxidant, anti-inflammatory and UV-protective functions promote human health, plus recent studies show they can be a tool in fighting obesity because they reduce digestibility, said Jianming Yu, associate professor of agronomy at Kansas State University. Tannins in sorghum also provide a natural chemical defense against bird predation and bacterial and fungal attack in the field.
On the other hand, tannins provide a bitter taste to some foods and decrease protein digestibility and feed efficiency in humans and livestock.
The team was led by Yu, along with Tesfaye Tesso, Kansas State University sorghum breeder and associate professor of agronomy and Scott Bean, scientist with the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) and adjunct faculty in the university's Department of Agronomy.
The researchers' study, "Presence of tannins in sorghum grains is conditioned by different natural alleles of Tannin1" was published in the June 26 issue of the Proceedings of the National Academy of Sciences of the United States of America (PNAS).
Sorghum is an old-world cereal grass that serves as a dietary staple for more than 500 million people in more than 30 countries, Yu said. In 2011, the United States was the No. 1 exporter of sorghum on the world market and the No. 2 producer (behind Nigeria), according to the U.S. Department of Agriculture. In 2011, Kansas produced 110.0 million bushels – 51 percent of the total U.S. crop. Sorghum production in the U.S., primarily for the feed industry, uses non-tannin sorghum hybrids.
Unlike many plants which employ C3 photosynthesis that uses water, carbon dioxide and solar energy to synthesize sugars, sorghum, which performs a modified form called C4 photosynthesis, has adapted to hot environments.
"One key reason to study tannins is to untangle their relationship with cold tolerance, a key agronomic trait to improve sorghum. The work is ongoing," said sorghum breeder Tesso. An earlier screening work found that a high proportion of cold tolerant sorghum lines contain tannins.
"Several other factors make tannins an important research subject," said Bean, noting their antioxidant capacity and relevant health benefits, their natural occurrence in some cereal crops, and their role in sorghum production. "Knowledge of tannins in biosynthesis pathways can be used to generate lines that produce high-content tannins in sorghum and other cereals to promote health through their unique nutritional properties."
This study, like many studies in recent years, benefits from work done several years ago on Arabidopsis, which are small flowering plants related to cabbage and mustard, said Yuye Wu, the first author and Kansas State University research associate of agronomy. "Many genes have been identified in Arabidopsis, through the mutational approach, but there is still much to be learned about the genetic control of tannins in cereal crops."
"This kind of genetic research in crops, coupled with nutritional and medical research, could open the possibility of producing different levels and combinations of phenolic compounds to promote human health," Yu said. What the researchers learn about tannins in sorghum will be beneficial to the future study of tannins in other plants, including some fruits, vegetables and a few other grains such as finger millets and barley.
Other researchers involved in the study were Mitch Tuinstra, Purdue University; Ming Li Wang, USDA-ARS, Griffin, Georgia; and Guihua Bai, USDA-ARS and adjunct professor of agronomy at Kansas State University.
The project was supported by USDA National Institute of Food and Agriculture, Department of Energy Plant Feedstock Genomics Program, National Science Foundation Plant Genome Research Program, USDA Agricultural Research Service, and the National Sorghum Checkoff program.
Jianming Yu | EurekAlert!
Researchers simplify tiny structures' construction drip by drip
12.11.2018 | Princeton University, Engineering School
Mandibular movement monitoring may help improve oral sleep apnea devices
06.11.2018 | Elsevier
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
19.11.2018 | Event News
09.11.2018 | Event News
06.11.2018 | Event News
19.11.2018 | Materials Sciences
19.11.2018 | Information Technology
19.11.2018 | Life Sciences