Effect of pH, Salt, and Biopolymer Ratio on the Formation of Pea Protein Isolate-Gum Arabic Complexes 

 -  J. Agric. Food Chem., 57(4), p.1521-1526, 2009 .
<br/><br/> 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 (e7.5 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. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>PEA PROTEIN ISOLATE<br/>GUM ARABIC<br/>COMPLEX COACERVATION