Light-scattering study of the structure of aggregates and gels formed by heat-denatured whey protein isolate and beta-lactoglobulin at neutral pH.
The structure of aggregates and gels formed by heat-denatured whey protein isolate (WPI) has been studied at pH 7 and different ionic strengths using light scattering and turbidimetry. The results were compared with those obtained for pure beta-lactoglobulin (beta-Lg). WPI aggregates were found to have the same self-similar structure as pure beta-Lg aggregates. WPI formed gels above a critical concentration that varied from close to 100 g/L in the absence of added salt to about 10 g/L at 0.2 M NaCl. At low ionic strength (<0.05 M NaCl) homogeneous transparent gels were formed, while at higher ionic strength the gels became turbid but had the same self-similar structure as reported earlier for pure beta-Lg. The length scale characterizing the heterogeneity of the gels increased exponentially with increasing NaCl concentration for both WPI and pure beta-Lg, but the increase was steeper for the former.
Mahmoudi
Najet
N
INRA-BIA, BP 71627; 44316 Nantes Cedex 3, France.
Mehalebi
Soraya
S
Nicolai
Taco
T
Durand
Dominique
D
Riaublanc
Alain
A
D005782:Gels / Q000737:chemistry; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007782:Lactoglobulins / Q000737:chemistry*; D008027:Light; D008894:Milk Proteins / Q000737:chemistry*; D011489:Protein Denaturation; D012542:Scattering, Radiation; D000067816:Whey Proteins
D005782:Gels; D007782:Lactoglobulins; D008894:Milk Proteins; D000067816:Whey Proteins