Characterization of fish gelatin–gum arabic complex coacervates as influenced by phase separation temperature

Ionic strength and hydrogen bonding effects on whey protein isolate–flaxseed gum coacervate rheology

“…Thus, lower temperature facilitated the formation of a sponge‐like porous microstructure of the fish gelatin‐GA coacervates with the water vacuoles entrapped became smaller and more homogenous in size. This results in a more compact coacervate microstructure due to favored non‐Coulombic interactions, such as hydrogen bonding, which can be related to greater elasticity of the coacervate phase (Anvari, Pan, Yoon, & Chung, 2015).…”

Effect of cooling–heating rate on sol-gel transformation of fish gelatin–gum arabic complex coacervate phase

“…The FG-GA mixture was incubated at 40 o C in a shaking water bath at 100 rpm for 24 h for sufficient electrostatic interactions between FG and GA molecules. Since it was found that the coacervates phase separated at lower temperatures had better rheological and structural properties [7], in the current study, the incubated mixtures placed statically at 10 and 30 o C for another 24 h for the macroscopic phase separation of FG-GA insoluble complexes to reach equilibrium state.…”

“…By prolongation of cooling from 0.05 to 0.012 o C, more rigid coacetvate gels with higher T g were formed, presumably due to formation of more hydrogen bindings, higher degree of helicity in conformation of FG molecules, and eventually, more alignment and stabilization of junction zones in the gel network. Besides, it was suggested that the presence of GA molecules, which electrostatically interacted with FG molecules, could facilitate the gelation of FG molecules [7]. This was explained by the volume exclusion effect and thermodynamic incompatibility between biopolymers, where the dispersed GA-rich phase acted as filler and increased the probability of association of FG molecules and reinforced the FG network.…”

“…Furthermore, the higher mass fraction of GA molecules in the coacervate phase separated at lower temperature might be other possible reason for facilitating of the gelation and formation of more compact coacervate gel structure [7].…”

“…The formation of soluble or insoluble FG-GA complexes was strongly influenced by pH, FG to GA weight ratio, and total concentration of biopolymers in the initial mixture. Secondly, it was gained by our group that the rheological and microstructural characteristics of FG-GA complex coacervate phase can be influenced by phase separation temperature, where the phase with higher viscous behavior and more condensed microstructure under the sol state followed by greater thermo-stability (higher gelling and melting temperatures) and gel strength under gel state was obtained by decreasing the phase separation temperature from 40 to 10 o C [7]. Notwithstanding the fact that the complex coacervation could enhance gelling properties of the FG, the rheological properties of the FG-GA coacervate gel is not suitable, at least for design of foods with desired texture or food-grade delivery systems for encapsulation of bioactive ingredients.…”