15A-1 |
The effects of whey proteins on fundamental dough rheology and white pan bread quality |
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 during the baking of bread products. They can be significant functional ingredients, improving crust color, crumb structure and flavor development in bread products, as well as improve the nutritional value. In terms of dough rheology, an increase in the dough mixing properties was reported when whey proteins were added to bread formulations. The objectives of this study were to determine the rheological dough properties of wheat flours with increased concentration of whey proteins and to determine the effect on staling properties of white pan breads. Whey protein concentrate (WPC) 34 (34% protein), WPC 65 (65% protein) and whey protein isolate (WPI) (88% protein) samples were mixed with flour at 4, 6 and 8% concentrations to determine mixograph and farinograph results. A conventional straight-dough bread making method (2 hr. fermentation) was applied. Bread quality indicators determined include crust and crumb color, loaf volume and texture parameters. The addition of whey proteins significantly decreased the water absorption value (P<0.01). A significant increase (P<0.01) in dough strength was observed for all whey protein samples. WPC65 addition showed the highest peak time, whereas WPC34 showed the highest stability value. All 4% whey protein supplements resulted in better bread quality than 6% and 8% levels. In terms of 4th day crumb firmness, 4% WPC65 and WPI samples gave lower firmness scores. Significant correlations were observed between crumb firmness and mixograph peak time (+0.78) (P<0.01), farinograph water absorption (-0.67) (P<0.01) and farinograph stability (+0.74) (P<0.01) values. WPI isolates gave the best crust color values within the samples. The 4% addition of whey proteins showed superior bread quality compared to the control samples. Considering the functional properties such as enhanced nutritional quality and improved color, whey proteins could be used as valuable ingredients for white pan bread making.
Session 15A, Dairy Foods
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