Rheological and surface properties of hydrocolloids in solution

Gums are water soluble polymers that serve as invaluable ingredients in a myriad of food applications. Gums have been extensively used in the beverage industry. Although, beverage systems are unique and do not follow the same rheological behavior as semi-solid systems. Thus, three connected studies were performed to characterize gums in dilute solutions.; The first study investigated the rheological properties of 12 gum solutions at concentrations of 0.05, 0.1, and 0.5% using an oscillatory capillary viscoelasticity analyzer. Elastic yield stress was measured at 0.5%. Konjac exhibited the highest viscosity and elasticity among all gums at 0.5% and 50 s −1. Pectin, gum arabic and methylcellulose exhibited the least viscosity and no elasticity. Konjac exhibited the greatest elastic yield stress, whereas microcrystallinecellulose had the least.; The second study investigated rheological and surface properties of solutions with added ι-carrageenan (IC) (0.05, 0.1, and 0.5%) or gum arabic (GA) (0.5, 1, and 5%) in combination with 4% deamidated wheat protein (DWP) or 4% whey protein concentrate (WPC). Addition of IC to DWP increased the viscosity and elasticity, but there was no effect of added GA to the DWP. Addition of IC to WPC increased the viscosity and elasticity. Addition of 5% GA increased the viscosity of the WPC. Adding IC to DWP or WPC increased all surface properties (except surface and interfacial tensions of IC-WPC solution). Addition of GA to DWP increased the surface tension, decreased the interfacial tension and emulsion activity index (EAI) (except at 5% GA), whereas adding GA to WPC increased the interfacial tension, EAI, and emulsion stability index.; The third study applied the fundamental behavior of gums and proteins in solution to develop a wheat protein beverage (WPB). A commercial beverage was used as a reference. One hundred and ten untrained panelists participated in the preference test. The sensory evaluation results showed that the mean values for the mouthfeel, flavor, and overall liking attributes for the WPB was 20.96, 8.08, and 14.60%, respectively, lower than the reference.