title: Stabilization of whey protein isolate-pectin complexes by heat.
abstract: Protein-polysaccharide complexes formed under electrostatic associative conditions could have interesting functional properties. However, their stability over a wide range of pH limits their widespread application. The aim of this work was to determine the time-temperature combination required to stabilize whey protein isolate (WPI) and pectin (LMP) complexes formed at pH 4.5 to a further pH adjustment to 7. The effect of storage for 28 days at 4 degrees C was also evaluated. Stability was confirmed by quantification of sugar and nitrogen in each phase after centrifugation. Three heat treatments were performed: 73 degrees C/5 min, 85 degrees C/15 min, and 90 degrees C/2 min. At 73 degrees C/5 min, adjustment to neutral pH led to disruption of WPI-LMP complexes. The most severe heating conditions (85 and 90 degrees C) allowed the stabilization of WPI-LMP complexes. Heated complexes (90 degrees C) could be preserved for up to 28 days of storage at 4 degrees C without affecting their stability.
authors.affiliation: Faculty of Agriculture and Food Science, Dairy Research Centre STELA, Pavillon Paul Comtois, Universite Laval, Quebec, Canada.
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Gentès
authors.forename: Daniel
authors.initials: D
authors.lastname: St-Gelais
authors.forename: Sylvie L
authors.initials: SL
authors.lastname: Turgeon
mesh_terms: D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008894:Milk Proteins / Q000737:chemistry*; D010368:Pectins / Q000737:chemistry*; D011485:Protein Binding; D055550:Protein Stability; D000067816:Whey Proteins
chemical_list: D008894:Milk Proteins; D000067816:Whey Proteins; D010368:Pectins