Wang conducts research for the Arkansas Agricultural Experiment Station, the research arm of the U of A System Division of Agriculture. Her collaborators on the research include Annegret Jannasch, a doctoral student in the Dale Bumpers College of Agricultural, Food and Life Sciences, who works under the direction of Wang; Anna McClung, a recently retired research geneticist at the Dale Bumpers National Rice Research Center; Sun-Ok Lee, associate professor of nutrition for the experiment station; post-doctoral researcher Zeina Alraawi; and Suresh Thallapuranam, Cooper Chair of Bioinformatics Research and professor of biochemistry.
Wang, Jannasch and Lee work in the Food Science Department in the Bumpers College. Thallapuranam is joining the team from the Chemistry and Biochemistry Department in the Fulbright College of Arts and Sciences.
McClung provides the researchers with pigmented waxy rice samples.
"We propose that pigmented waxy rice can function like chemically modified starches but without the use of chemicals, so it will be a clean label ingredient," Wang said.
"Clean label" is not a scientific term, but the food industry, academics and consumers define the phenomenon as choosing foods with easy-to-recognize ingredients and no artificial ingredients or synthetic chemicals, according to the Institute of Food Technologists.
CONSUMER PERCEPTION
In recent years, consumers have raised concerns about ingredients used in food production, Wang noted. Some consumers aim to consume only minimally processed food.
The idea of minimal processing varies from person to person, Wang said. Some consumers prefer wheat flour, but others might consider wheat flour too processed and consume whole wheat flour instead.
"A lot of processed food is really for preservation or convenience," Wang said. Food products such as ham, pickles and TV dinners, for example, are processed to help simplify food preparation for the consumer and to extend shelf life.
Wang's research may alleviate these concerns related to modified starch.
Many foods contain modified starch, which is chemically altered to improve processing and storage stability, Wang said. Starches function as thickening agents to improve the texture and consistency of food products.
The inspiration for this project came from Wang's recent research that explored the possibility of utilizing the interactions among polyphenols, protein and starch in pigmented waxy rice to increase satiation, the feeling of fullness. In that original project, Wang found that the pigmented waxy rice's unique interactions between polyphenols and proteins allow starch to swell more in an acidic condition that simulates gastric environments.
"Starch, when it swells, is like a balloon — it becomes bigger and bigger," Wang said. During food processing, "the temperature, the shear, the high acidity will completely break down the balloon. You want the balloon to swell more — that is how you create the viscosity — but you don't want it to swell too much. The polyphenol-protein interactions help to maintain the starch structure so it will stay at that stage.
"That is why you can use starch to thicken any soup because the starch can swell more than 10 times its volume, but once it gets to that stage, it becomes very fragile," she said.
Outside of consumer perception, Wang said that applying this pigmented waxy rice, as opposed to using modified starch, could provide additional environmental and health benefits.
With any chemical modification comes a residue, Wang said, so using a naturally occurring starch with these properties eliminates that concern. Polyphenols are present in many berries and vegetables, and a high amount of polyphenols are known to have anti-oxidant, anti-inflammatory and antidiabetic properties.
A THREE-PHASE APPROACH
The research will take place in three phases. Wang and her team have finished the first phase, which evaluated pigmented waxy rice samples and their contents and compositions of proteins, starch and polyphenols. A research article titled "Elucidating the effect of polyphenol-protein interactions on rheological properties of purple waxy rice" was published in the Journal of Cereal Science this month.
The next phase will determine the nature of the polyphenol-protein interactions in pigmented waxy rice. Interactions between polyphenols and proteins involve chemical bonds linking two molecules, and it is important because a strong bond helps maintain granule integrity under high shear, temperature and acidic conditions, Wang said.
Finally, the researchers will apply thermal processing conditions to alter the extent of polyphenol-protein interactions so the resulting products will produce a wide range of viscosities for different applications.
"We really want to see the possibility of commercializing the resulting technology," Wang said. "We want to see if any companies are interested and work with them."
Companies using this to make cereals, pudding or pasta is something that Wang hopes to see.
Wang will share an update on this research at the USDA-NIFA project director meeting in Amherst, Massachusetts, on June 17-18.
Source : uark.edu