title: Using state diagrams for predicting colloidal stability of whey protein beverages.
abstract: A method for evaluating aspects of colloidal stability of whey protein beverages after thermal treatment was established. Three state diagrams for beverages (pH 3-7) were developed representing protein solubility, turbidity, and macroscopic state after two ultrahigh-temperature (UHT) treatments. Key transitions of stability in the state diagrams were explored using electrophoresis and chromatography to determine aggregation propensities of β-lactoglobulin, α-lactalbumin, bovine serum albumin, and glycomacropeptide. The state diagrams present an overlapping view of high colloidal stability at pH 3 accompanied by high solubility of individual whey proteins. At pH 5, beverages were characterized by poor solubility, high turbidity, and aggregation/gelation of whey proteins with the exception of glycomacropeptide. Stability increased at pH 6, due to increased solubility of α-lactalbumin. The results indicate that combinations of state diagrams can be used to identify key regions of stability for whey protein containing beverages.
authors.affiliation: †Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, North Carolina 27695-7624, United States.
authors.forename: Ty B
authors.initials: TB
authors.lastname: Wagoner
authors.affiliation: §Glanbia Nutritionals, 450 Falls Avenue, Twin Falls, Idaho 83301, United States.
authors.forename: Loren
authors.initials: L
authors.lastname: Ward
authors.affiliation: †Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Box 7624, Raleigh, North Carolina 27695-7624, United States.
authors.forename: E Allen
authors.initials: EA
authors.lastname: Foegeding
mesh_terms: D000818:Animals; D001628:Beverages / Q000032:analysis*; D002417:Cattle; D003102:Colloids / Q000737:chemistry; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007768:Lactalbumin / Q000737:chemistry; D007782:Lactoglobulins / Q000737:chemistry; D008894:Milk Proteins / Q000737:chemistry*; D066329:Protein Aggregates; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012995:Solubility; D000067816:Whey Proteins
chemical_list: D003102:Colloids; D007782:Lactoglobulins; D008894:Milk Proteins; D066329:Protein Aggregates; D000067816:Whey Proteins; D012710:Serum Albumin, Bovine; D007768:Lactalbumin
keywords: beverage; heat treatment; solubility; stability; turbidity; whey protein isolate