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Film Extrusion of Crambe abyssinica/Wheat Gluten Blends
Published on: January 17, 2017
Physical properties, molecular structures, and protein quality of texturized whey protein isolate: effect of
Phoebe X Qi1, Charles I Onwulata
1Dairy and Functional Foods Research Unit, Eastern Regional Research Center, Agricultural Research Service, US Department of Agriculture, Wyndmoor, Pennsylvania 19038, United States. Phoebe.Qi@ars.usda.gov
Abstract:
Although extrusion technology has contributed much to increasing the effective utilization of whey, the effect of extrusion conditions on the functional properties of the proteins is not well understood. In this work, the impact of extrusion temperature on the physical and chemical properties, molecular structures, and protein quality of texturized whey protein isolate (WPI) was investigated at a constant moisture content and compared with WPI treated with simple heat only. The Bradford assay methods, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and reversed-phase high-performance liquid chromatography techniques were used to determine protein solubility and to analyze compositional changes in the two major whey proteins, α-lactalbumin and β-lactoglobulin. Circular dichroism and intrinsic tryptophan fluorescence spectroscopic techniques were applied to study the secondary and tertiary structures of the proteins. This study demonstrated that extrusion temperature is a critical but not the sole determining factor in affecting the functional properties of extruded WPI.
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