Research Puts Soybeans Under Pressure
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| Stephanie Jung did her doctoral research in France on high-pressure processing, then worked in other areas before returning to her "first love" at Iowa State. |
Three lab coats hang in Stephanie Jung's office at Iowa State's Food Sciences Building. The one for regular lab work is a pristine white. She wears the other two, sporting brown blotches and stains, to work on her research subject: high hydrostatic pressure processing (HHPP).
The processors use tanks of water at high pressure to eliminate microbes, making food safer and longer lasting. Jung's experiments use pressure as high as 900 megapascals – 90 times that generated by a typical pressure washer. But as the coats show, equipment doesn't always cooperate.
"I've learned a lot about tubing and piping," said Jung, an assistant professor of food science and human nutrition.
Jung, an affiliate of the Center for Crops Utilization Research, studies how HHPP affects food components like proteins and enzymes. HHPP is used to preserve meats, seafood and other foods, but little is known about how it affects some nutrients.
HHPP could be useful for soybeans, which must be thermally processed to inactivate trypsin inhibitor, which limits soy nutrition, and lipoxygenase, an enzyme responsible for undesirable flavor change. But thermal processing also cuts available soy protein and beneficial chemicals.
Jung is testing whether HHPP can make soy products with inactivated enzymes and more protein, plant chemicals and vitamins. She's also experimenting with HHPP parameters, like pressure level, duration and temperature.
"What is unique with the equipment at Iowa State is we can study the impact of rate of pressurization and depressurization," Jung said.
A native of France, Jung also is studying enzymes to improve soy-based industrial products. She and center director Lawrence Johnson are researching ways to use water and enzymes to separate soy oil and eliminate the use of hexane, a flammable, pollution-prone chemical.
