title: Effect of gum tragacanth exuded by three Iranian Astragalus on mixed milk protein system during acid gelation.
abstract: The effects of various concentrations of three species of gum tragacanth on the gelation process, microstructure and viscoelastic properties of milk protein mixed gels acidified at 37°C by glucono-δ-lactone (GDL) were investigated using dynamic rheometry and microscopy. According to rheological measurements, the addition of gum tragacanth in the range of 0.05-0.2% (w/w) into milk protein dispersions led to a weaker structure for the milk protein network, compared to the control sample. This weakening effect could be eliminated by adding 0.3% (w/w) gum tragacanth exudates from A. gossypinus; the compositional features of gum tragacanth may have been responsible for the improved protein-protein interactions, greater structural strength and reduced gelation time onset. It was determined by scanning electron microscopy that the addition of gum tragacanth at a low concentration caused the density of the matrix to increase, while an open structure was observed in the presence of a higher gum concentration.
authors.affiliation: Department of Food Science and Technology, National Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, 193954741 Tehran, Iran. nejati.m64@gmail.com
authors.forename: Mohammad
authors.initials: M
authors.lastname: Nejatian
authors.forename: Masoud
authors.initials: M
authors.lastname: Hatami
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Mohammadifar
mesh_terms: D027883:Astragalus Plant / Q000737:chemistry*; D004548:Elasticity; D005782:Gels; D006863:Hydrogen-Ion Concentration; D007492:Iran; D008894:Milk Proteins / Q000737:chemistry* / Q000648:ultrastructure; D012212:Rheology; D013816:Thermodynamics; D014144:Tragacanth / Q000737:chemistry* / Q000648:ultrastructure; D055682:Viscoelastic Substances / Q000737:chemistry*; D014783:Viscosity
chemical_list: D005782:Gels; D008894:Milk Proteins; D055682:Viscoelastic Substances; D014144:Tragacanth