title: Effect of pH, salt, and biopolymer ratio on the formation of pea protein isolate-gum arabic complexes.
abstract: Turbidity measurements were used to study the formation of soluble and insoluble complexes between pea protein isolate (PPI) and gum arabic (GA) mixtures as a function of pH (6.0-1.5), salt concentration (NaCl, 0-50 mM), and protein-polysaccharide weight mixing ratio (1:4 to 10:1 w/w). For mixtures in the absence of salt and at a 1:1 mixing ratio, two structure-forming transitions were observed as a function of pH. The first event occurred at a pH of 4.2, with the second at pH 3.7, indicating the formation of soluble and insoluble complexes, respectively. Sodium chloride (<or=7.5 mM) was found to have no effect on biopolymer interactions, but interfered with interactions at higher levels (>7.5 mM) due to substantial PPI aggregation. The pH at which maximum PPI-GA interactions occurred was 3.5 and was independent of NaCl levels. As PPI-GA ratios increased, structure-forming transitions shifted to higher pH.
authors.affiliation: Department of Food and Bioproduct Sciences, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan, Canada.
authors.forename: Shuanghui
authors.initials: S
authors.lastname: Liu
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Low
authors.forename: Michael T
authors.initials: MT
authors.lastname: Nickerson
mesh_terms: D001704:Biopolymers / Q000032:analysis*; D006170:Gum Arabic / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009391:Nephelometry and Turbidimetry; D018532:Pisum sativum / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry*; D012965:Sodium Chloride / Q000032:analysis* / Q000494:pharmacology; D012995:Solubility
chemical_list: D001704:Biopolymers; D010940:Plant Proteins; D012965:Sodium Chloride; D006170:Gum Arabic