30E-18 |
The effects of whey proteins and transglutaminase(TG) on the fundamental rheological properties of wheat flour dough |
M. C. TULBEK, Department of Cereal and Food Sciences, North Dakota State University, P.O. Box 5728, Fargo, ND 58105 and J. G. Schwarz. Whey proteins find limited use as functional ingredients during bread making. Due to the high amount of lysine, whey proteins could be used to improve the functional properties of baked goods in conjunction with transglutaminase (TG). TG enzyme is able to cross-link lysine and glutamine amino acids of whey proteins and wheat proteins. The objectives of this study were i-) To determine the combined effects of whey proteins and TG enzyme on the fundamental dough properties of wheat flour dough samples and ii-) To improve the mixing and rheological behaviors of medium quality wheat flour. TG enzyme was added to medium gluten strength wheat flour fortified with whey protein concentrate (WPC) 34 (34% protein), WPC 65 (65% protein) and whey protein isolate (WPI) (88% protein) samples at 4, 6 and 8% concentrations. Mixograph, extensigraph, and dynamic oscillatory measurements were conducted. Overall dough structure was determined with plots of the complex modulus (G*) for dynamic oscillatory analysis. Mixograph data showed significantly longer mixing times at 8% whey protein concentration (P<0.05) when TG enzyme was added. Mixograph peak height values decreased with increasing whey protein concentration. In terms of extensigraph data, TG enzyme caused lower maximum resistance values for WPC65 and WPC34 samples, compared to the controls. However a significant increase in maximum resistance was observed with WPI samples and TG enzyme. Dynamic rheological analysis demonstrated that TG enzyme combined with all whey protein samples, increased the complex modulus (G*) value indicating stronger dough properties. The fundamental rheological properties of the whey protein fortified wheat flour samples were affected by the addition of TG enzyme. In the presence of TG, WPI samples improved the overall rheological properties of the dough.
Session 30E, Food Engineering: Rheology and texture
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