|Seabourn, Bradford - Brad|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2008
Publication Date: 7/1/2008
Citation: Seabourn, B.W., Xie, F., Chung, O.K. 2008. Rapid determination of dough optimum mixing time for early generation breeding lines using FT-HATR infrared spectroscopy. Crop Science. 48:1575-1578. Interpretive Summary: More objective methods for measuring the development of wheat flour/water (dough) systems, preferably methods based on the chemical characteristics of dough component interaction(s), have long been desired by cereal chemists. The mixograph and farinograph are traditional methods that have been used to determine the mixing characteristics of dough for many years, but these devices are subjective and labor-intensive. Wheat breeders have also used the mixograph in their laboratories for screening early generation breeding lines for end-use quality characteristics. Yet, in the breeding laboratory, where thousands of samples are concerned, the labor involved in the traditional methods is even more of an issue. The use of infrared spectroscopy in biological applications, particularly in the characterization of proteins, has seen an unprecedented increase in recent years. The purpose of this study was to use infrared spectroscopy to measure the changes in protein structure that occur very early in the dough mixing process, and use this information as a predictive tool independent of the traditional devices used to measure mixing quality. Results showed that it was feasible to predict optimum mix time of a dough system after as little as one minute of flour hydration and mixing, and based solely on changes in protein structure observed in the infrared spectra of the sample. This technique shows promise as the basis for development of less expensive instrumentation that would provide rapid and accurate assessment of end-use quality characteristics of dough in the breeding laboratory.
Technical Abstract: The traditional method in the U.S. for screening hard winter wheat breeding lines is based upon the optimum mixing time (MT), an important rheological property of a wheat flour-water (dough) system typically obtained from the mixograph. This method is time-consuming and requires some degree of subjective interpretation, especially with regard to mixing tolerance. The purpose of this study was to investigate the potential of FT-HATR spectroscopy to objectively predict optimum MT in doughs from a short-duration mixing cycle (1 min). Hard winter wheat flours with varying protein contents and MT were scanned in the amide III region of the mid-infrared by FT-HATR immediately after being mixed 1 min with a mixograph. The ratio of the band areas at 1336 cm-1 (alpha-helix) and 1242 cm-1 (beta-sheet) was highly correlated to optimum MT as determined by the mixograph (R2 = 0.81). Results from this study indicate that optimum MT could be predicted early in the mixing process based upon changes in the secondary structure of the dough protein. This method could provide the basis for new technology to rapidly and accurately screen wheat samples in early generation breeding lines, thus saving considerable time and expense in the development of new cultivars.