Effects of salt ions and heating on the behaviour of whey protein particle dispersions
Küçük Resim Yok
Tarih
2020
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Sci Ltd
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
We investigated the aggregation stability of whey protein isolate (WPI) particles in the presence of different salts (NaCl2, MgCl2, and AlCl3) and the heat stability of dispersions in the presence of protein (native WPI) and polysaccharides (dextran and gum Arabic, GA). WPI particles coagulated either at pH values close to the isoelectric point of proteins or at high salt concentrations. Critical coagulation concentration (CCC) for different salts decreased with increasing valence of ions. CCC values for colloidal WPI particle dispersions closely followed the Schulze-Hardy rule, which is derived from the DLVO theory; however, deviations from the theory, particularly in the case of multivalent ions, showed that the specific ion adsorption also played a role. To investigate the heat stability of WPI particles, particle size and viscosities of dispersions containing different biopolymers were measured. Using dynamic viscosity of dilute dispersions, with the assumption of no particle aggregation after heating, swelling ratio (SR) of particles was estimated. Increasing concentrations of biopolymers decreased the SR of particles, and the presence of GA totally inhibited the swelling. Shear viscosity of concentrated dispersions showed an increase and shear-thickening behaviour after heating, when native WPI or dextran was present, whereas viscosity did not change when GA was present in the continuous phase. At low volume fractions, swelling was more likely to occur; whereas at high volume fractions, possibly both swelling and aggregation occurred. in addition, concentration and type of biopolymer were found to be important for the heat stability of dispersions.
Açıklama
Anahtar Kelimeler
Colloidal stability, Critical coagulation concentration, Dextran, Gum Arabic, Heat stability, Multivalent ions
Kaynak
Food Hydrocolloids
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
101
