Abstract
The effect that ratios of fish gelatin (FG) to α/β/γ cyclodextrins (α, β, γCDs) had on the phase behavior of a concentrated biopolymer mixture were comparatively investigated. This showed that the formed biopolymer mixture had the highest gel strength at ratios of FG–CD = 90:10. FG could interact with CDs to form stable soluble complexes with lower values of turbidity, particle size and ζ-potential. All of the FG–CD mixture solutions exhibited pseudo-plastic behaviors, and FG–αCD samples had the highest viscosity values than others. The addition of CDs could unfold FG molecules and make conformation transitions of FG from a random coil to β-turn, leading to the environmental change of hydrophobic residues and presenting higher fluorescence intensity, especially for βCDs. FTIR results revealed that the formation of intermolecular hydrogen bonds between FG and CD could change the secondary structure of FG. These findings might help further apply FG–CD complexes in designing new food matrixes.
Highlights
Proteins and polysaccharides have been widely used as functional ingredients as natural biopolymers in the food industry [1]
Sow et al [8] reported that fish gelatin and low concentrations of sodium alginate could form stable complex coacervates through the electrostatic interactions, improving gel strength and the hardness of gelatin gels
With the further increase in CDs (60:40–20:80), fish gelatin (FG)–CD gels have similar gel strength values to pure gelatin gels (3.0–1.0%). This might be attributed to the introduction of more and more negatively charged CDs, increasing the repulsion force among FG and CDs and weakening gel network (Huang et al, 2018, Sow et al, 2019)
Summary
Proteins and polysaccharides have been widely used as functional ingredients as natural biopolymers in the food industry [1]. When proteins and polysaccharides have opposite charges, associative electrostatic interactions make proteins and polysaccharides form complexes through electrostatic attraction [3,5]. The formed biopolymers still have complex coacervation behaviors, which are mainly determined by the electrostatic interactions, such as molecular properties (charge density and size), environmental factors (pH, mixing ratio of proteins and polysaccharides, salt, total concentration of biological macromolecules and temperature) and other factors (shear rate) [5,6]. Sow et al [8] reported that fish gelatin and low concentrations of sodium alginate could form stable complex coacervates through the electrostatic interactions, improving gel strength and the hardness of gelatin gels. The underlying mechanism was evaluated by the UV absorption spectrum, far-UV circular dichroism spectroscopy, fluorescence spectroscopy and Fourier transform infrared spectroscopy
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
