A scientific first can be claimed by Kansas State University's David Wetzel, professor of grain science and industry, and Yong-Cheng Shi, associate professor in grain science and industry, and their colleague John Reffner, professor of chemistry at John Jay College, City University of New York.
The trio was able to apply microscopic chemical imaging to single modified starch granules. Starch manufacturers can use this to determine if the modifying agent used in the production process is uniformly distributed across individual modified starch granules.
Mark Boatwright, K-State graduate research assistant in grain science and industry, Runnells, Iowa, assisted with data processing for the study.
Wetzel said the techniques developed in the study can be used in industry, not only for food -— the largest industry for starch — but also for papermaking, corrugated board adhesives, clothing/laundry starch, body powder and as a viscosity adjuster for drilling fluid used in oil exploration, among other uses.
"From the industrial standpoint, modified starch is big business. It's modified to provide emulsifying properties to suit a particular use," Wetzel said.
"Now, we can basically show that anyone dealing with starch or any other particle of material that's microscopic in size and that suspects chemical heterogeneity can follow the same lead and use the same technique to check," Wetzel said.
Isolating the modification within an individual granule was no easy feat, as a single modified starch granule has a diameter of 15 microns — or one-fifth the width of a human hair. A normal human hair measures 80 microns wide. A micron is one-millionth of a meter.
To analyze the single granule at that size, the researchers traveled to the National Synchrotron Light Source at Brookhaven National Laboratory in Upton, N.Y., to use the facility's advanced synchrotron infrared microscope. The synchrotron microscope uses extremely bright light that has no thermal noise. It is narrowly focused like a laser but contains a continuum of wavelengths.
"We used this high technology to accomplish this supposedly impossible task," Wetzel said. "But, as it turns out, this task was achievable.
"Either nobody else has been successful, has thought of it or has been crazy enough to attempt this," Wetzel said with a laugh. "We were the first."
The results were reported in the March 2010 edition of the journal Applied Spectroscopy, "Synchrotron Infrared Confocal Microspectroscopical Detection of Heterogeneity Within Chemically Modified Single Starch Granules."
Wetzel has recently pursued this work further, using the Wisconsin synchrotron instrumentation.
Wetzel has been a guest lecturer at synchrotrons in Germany, Canada and Taiwan on the subject of studying biological material with synchrotron radiation.
The study was possible through the cooperation with National Synchrotron Light Source, operated by the U.S. Department of Energy, as a user facility.
Source: Brookhaven National Laboratory
