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Pasting and extrusion properties of mixed carbohydrates and whey protein isolate matrices

Charles I. Onwulata, Michael H. Tunick, Audrey E. Thomas-Gahring
Journal of food processing and preservation 2014 v.38 no.4 pp. 1577-1591
barley, corn starch, extrusion, foods, gels, hardness, mixing, pastes, pasting properties, peas, protein sources, starch, texture, texturization, viscoelasticity, viscosity, water content, whey, whey protein isolate
Mixed systems of whey protein isolate (WPI) or texturized WPI (tWPI) and different starches may form weak or strong gel pastes or rigid matrices depending on interactions. The paste viscoelasticity of starches from amioca, barley, corn starch, Hylon VII, plantain, and pea starch, mixed with whey protein isolate or textured WPI at the concentrations of 75/25, 50/50, or 25/75 wt% was determined using a Rapid Visco-Analyzer (RVA). Peak paste ranged from plantain (5.33 Pa.s), amioca (4.14 Pa.s), corn starch (3.65 Pa.s), barley (2.61 Pa.s), Hylon VII and pea starch (0.10 Pa.s). The presence of whey proteins reduced paste viscosity and extrusion expansion, but reduced hardness and improved fracturability. Moisture content was a stronger determinant of paste properties and of the denatured state of the whey protein isolate.