title: Effect of calcium on the morphology and functionality of whey protein nanofibrils.
abstract: Self-assembly of amyloid-like nanofibrils during heating of bovine whey proteins at 80 °C and pH 2 is accelerated by the presence of NaCl and/or CaCl(2), but the rheological consequences of accelerated self-assembly are largely unknown. This investigation focused on the impact of CaCl(2) on the evolution of rheological properties and fibril morphology of heated whey protein isolate (WPI), both during self-assembly at high temperature and after cooling. Continuous rotational rheometry of heated 2% w/w WPI showed a nonlinear effect of CaCl(2) on the viscosity of fibril dispersions, which we attributed to effects on fibril flexibility and thus the balance between intrafibril and interfibril entanglements. Small-amplitude oscillatory measurements made in situ during heating of 10% w/w WPI at 80 °C suggest that CaCl(2) is not involved in either fibril structure or gel structure, and this was confirmed with dialysis experiments.
authors: Riddet Institute, Massey University, Private Bag 11 222, New Zealand.
authors: Simon M
authors: SM
authors: Loveday
authors: Jiahong
authors: J
authors: Su
authors: M Anandha
authors: MA
authors: Rao
authors: Skelte G
authors: SG
authors: Anema
authors: Harjinder
authors: H
authors: Singh
mesh_terms: D000682:Amyloid / Q000032:analysis / Q000737:chemistry / Q000648:ultrastructure; D000818:Animals; D040761:Biomimetic Materials / Q000032:analysis / Q000737:chemistry*; D002122:Calcium Chloride / Q000737:chemistry; D002417:Cattle; D003956:Dialysis; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D046529:Microscopy, Electron, Transmission; D008894:Milk Proteins / Q000032:analysis / Q000737:chemistry*; D057139:Nanofibers / Q000032:analysis / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D012212:Rheology; D012965:Sodium Chloride / Q000737:chemistry; D014783:Viscosity; D000067816:Whey Proteins
chemical_list: D000682:Amyloid; D008894:Milk Proteins; D000067816:Whey Proteins; D012965:Sodium Chloride; D002122:Calcium Chloride