title: Self-assembly of β-lactoglobulin and the soluble fraction of gum tragacanth in aqueous medium.
abstract: Spectrophotometric and light scattering measurements, along with optical microscopy, were used to follow the complexation and coacervation process that occur when β-lactoglobulin (BLG)/tragacanthin (T) mixed dispersions (0.3 wt.% total concentration; BLG:T ratio of 2:1) were brought from pH 6 to pH 2. In addition, the coupling of slow in situ acidification of the mixture and rheometry was utilised to gain deeper insights into pH-induced structural transitions during the assembly process. The results obtained by this multi-methodological approach allowed the associative phase separation process to be parameterised in terms of a set of characteristic pH values (~5.3, ~4.8, ~4.5, ~4.15, ~4, ~3.8, ~2.5) at which critical structural changes took place. Investigation of the absorbance profiles of complexed/coacervated systems as a function of time revealed that several transitions could occur at different time scales. Morphological changes in the assemblies and the subsequent formation of some flocculant substances during the late stage of process were clearly visualised using microscopy.
authors.affiliation: Department of Food Science and Technology, Faculty of Nutrition Sciences, Food Science and Technology/National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Mahtab Hasandokht
authors.initials: MH
authors.lastname: Firooz
authors.forename: Mohammad Amin
authors.initials: MA
authors.lastname: Mohammadifar
authors.forename: Parivash
authors.initials: P
authors.lastname: Haratian
mesh_terms: D000818:Animals; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D007782:Lactoglobulins / Q000737:chemistry* / Q000378:metabolism*; D010316:Particle Size; D011485:Protein Binding; D012212:Rheology; D012995:Solubility; D014144:Tragacanth / Q000737:chemistry* / Q000378:metabolism*; D014867:Water / Q000737:chemistry*
chemical_list: D007782:Lactoglobulins; D014867:Water; D014144:Tragacanth