title: Influence of sulphate, chloride, and thiocyanate salts on formation of β-lactoglobulin-pectin microgels.
abstract: Effects of sulphate, chloride, and thiocyanate salts on the heat-induced formation of protein-based microgels from β-lactoglobulin-pectin complexes were determined as a function of pH and protein-to-polysaccharide ratio. Aggregation temperatures were initially decreased at low ionic strength due to shielding of electrostatic interactions between β-lactoglobulin and pectin but increased with further increases in ionic strength. Turbidity of heated mixtures and associated sizes of formed microgels were increased with up to 75 mmol kg(-1) ionic strength. Aggregation and microgel formation were relatively increased in the presence of thiocyanate salts compared to chloride salts and relatively decreased in the presence of sulphate salts, indicating that the inverse Hofmeister series was relevant in this system. Topographical analysis of dried microgels by atomic force microscopy verified that microgels were smallest in the presence of sulphate salts and showed that added ions, particularly thiocyanate, increased the deformability of microgels during drying.
authors.affiliation: Purdue University, Department of Food Science, 745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
authors.forename: Stacey
authors.initials: S
authors.lastname: Hirt
authors.affiliation: Purdue University, Department of Food Science, 745 Agriculture Mall Drive, West Lafayette, IN 47907, USA. Electronic address: joneso@purdue.edu.
authors.forename: Owen G
authors.initials: OG
authors.lastname: Jones
authors.affiliation: Purdue University, Department of Food Science, 745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
authors.forename: Marilyn
authors.initials: M
authors.lastname: Adijanto
authors.affiliation: Purdue University, Department of Food Science, 745 Agriculture Mall Drive, West Lafayette, IN 47907, USA.
authors.forename: Jay
authors.initials: J
authors.lastname: Gilbert
mesh_terms: D002712:Chlorides / Q000737:chemistry / Q000494:pharmacology*; D005782:Gels / Q000737:chemistry; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007782:Lactoglobulins / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D009994:Osmolar Concentration; D010368:Pectins / Q000737:chemistry*; D012492:Salts / Q000737:chemistry; D055672:Static Electricity; D013431:Sulfates / Q000737:chemistry / Q000494:pharmacology*; D013861:Thiocyanates / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D002712:Chlorides; D005782:Gels; D007782:Lactoglobulins; D012492:Salts; D013431:Sulfates; D013861:Thiocyanates; D010368:Pectins; C031760:thiocyanate
keywords: Aggregation; Hofmeister; Microgel; Pectin; Specific ion; β-Lactoglobulin