Abstract
[Display omitted]
•Ultrasound-assisted salts solution (Na+ or Ca2+) dialysis to form and modify alcohol-free Zein nanocomplexes.•Dialysate type has different effects on Zein-NaCas and Zein-Gum arabic nanoparticles.•Ca2+ dialysis can improve the storage stability, thermal stability, and encapsulation efficiency of the nanocomplexes. On the contrary, Na+ dialysis reduced the thermal stability and encapsulation efficiency of the nanocomplexes.•The main driving force of nanoparticles formation induced by Ca2+ or Na+ dialysis is probably hydrogen bonding and electrostatic interactions.
This study aims to investigate the effect of the dialysate type on the properties of nanocomplexes. Nanocomplexes of zein-sodium caseinate-curcumin (Z-N-C) and zein-gum arabic-curcumin (Z-G-C) were prepared by ultrasound-assisted dialysis using salt solutions of different concentrations (Na+ and Ca2+; 2 – 10 mM). With increasing Na+ concentration, the overall particle size of Z-N-C and Z-G-C decreased first and then increased. The Ca2+ concentration did not affect the particle size of Z-N-C and Z-G-C, with good storage stability. The encapsulation efficiency of Z-N-C decreased significantly from 72.3±6.2% to 59.8±8.6% with increasing Na+ concentration, while that of Z-G-C increased first and then decreased. The encapsulation efficiency of Ca2+ treated Z-N-C nanoparticles was higher than that of Na+ induced nanoparticles. Ca2+ did not affect the encapsulation efficiency of Z-G-C nanoparticles. Fluorescence spectroscopy analyses, CD, FTIR, and XRD showed Na+ and Ca2+ dialysis modified the secondary structure of Z-N-C and Z-G-C through adding hydrogen bonding and electrostatic interactions. Na+ and Ca2+ improved the thermal stability of Z-G-C and reduced the thermal stability of Z-N-C. After encapsulating curcumin, the crystallinity of Z-N-C and Z-G-C induced by Na+ and Ca2+ decreased to 45.9% - 63.9%, and the amorphous area increased. The above results indicated that Ca2+ dialysis could increase the encapsulation efficiency and thermal stability of the nanoparticles, and improve the loading characteristics of zein nanoparticles. The Z-G-C nanoparticles induced by Na+ and Ca2+ showed better thermal and storage stability.