Enhancing the Dispersion Stability and Sustained Release of S/O/W Emulsions by Encapsulation of CaCO3 Droplets in Sodium Caseinate/Xanthan Gum Microparticles

Abstract

In this study, solid/oil/water (S/O/W) emulsions were prepared by sodium caseinate (NaCas) and Xanthan gum (XG) binary composite to improve the dispersion stability of calcium carbonate (CaCO3) and achieve a targeted slow-release effect. CaCO3 S/O/W emulsions were determined by particle size, Zeta potential, physical stability, and microstructure. X-ray diffraction (XRD), Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR) were used to characterize the molecular interactions among components. Molecular docking technology was used to predict the possible binding mode between NaCas-XG. The percentage of free Ca2+ released in the gastrointestinal tract (GIT) model was also studied. It was found that when the concentration of XG was 0.5 wt% and pH was 7, the particle size was smaller, the distribution was uniform, and the physical stability was improved. The microstructure results showed that the embedding effect of S/O/W emulsions was better, the particle size distribution was more uniform when XG concentration increased and formed a filament-like connector with a relatively more stereoscopic structure. XRD results confirmed that the CaCO3 was partially covered due to physical embedding. Infrared and Raman analysis and molecular docking results showed electrostatic and hydrophobic interaction between NaCas and XG. In the GIT digestion model, S/O/W emulsion released Ca2+ slowly in the gastric digestion stage, which proved the targeted slow-release effect of the S/O/W emulsions delivery vector. The results showed that the S/O/W emulsions delivery system is an effective way to promote the application of CaCO3.

Structural changes and calcium bioaccessibility of calcium fortified milk containing CaCO3 loaded solid‐in‐oil‐in‐water emulsion during simulated in vitro digestion

“…When the concentration of was 4 g L −1 , the average particle size was the smallest (4.49 ± 0.02 μm), indicating that the emulsification of the emulsion was the best and the emulsion state was the most stable. This may be due to the fact that the XG and WPI composite reduced interfacial tension 19,20 …”

“…This may be due to the fact that the XG and WPI composite reduced interfacial tension. 19,20 The zeta potential can reflect the electrostatic interaction between particles in the emulsion dispersion system. Usually, the larger the absolute value of the zeta potential, the stronger the electrostatic repulsion between droplets, which is conducive to the stability of the whole system.…”

Encapsulation of calcium carbonate with a ternary mixture of sodium caseinate/gelatin/xanthan gum to enhance the dispersion stability of solid/oil/water emulsions

“…The diffraction peaks of S/O/W emulsion were 7.2, 20, 23, 29, 36, 39, 43, 47.5, and 48.5, respectively, indicating that the characteristic peak of CaCO 3 was partially covered and the intensity of the characteristic peak was weakened due to physical embedding. Compared with the S/O/W emulsions with stable W phases of NaCas, NaCas-GEL, and NaCas-XG, the S/O/W emulsions with a stable ternary mixture of NaCas-GEL-XG have enhanced the embedding effect of CaCO 3 ( 28 , 32 ).…”

“…Compared with NaCas, NaCas-GEL, and NaCas-XG in phase W, the potential value of the microspheres was lower, which was due to electrostatic interaction in the mixed system. S/O/W emulsions (pH7.0) were negatively charged due to pH higher than the pI of NaCas, while GEL was positively charged, and electrostatic interaction between NaCas and GEL occurs, which was the result of interaction between GEL side groups (−NH 3+ ) and negative ions dissociated from NaCas ( 28 ). The addition of XG increased the absolute value of Zeta-potential slightly due to the negative charge caused by the presence of anionic polysaccharide.…”

“…With low NaCas concentration, the S/O/W emulsions could form a dense three-dimensional network space structure, indicating that the emulsion constructed with low NaCas concentration had good stability. In addition, low NaCas concentration could not form a three-dimensional network structure ( 22 ), while the binary compound of NaCas-XG formed a gelatinous network structure ( 28 ). The addition of GEL could effectively improve the gel-like properties of NaCas and XG, and promoted the formation of the honeycomb three-dimensional network structure of the S/O/W emulsion, and it is a benefit to improve the stability of the system.…”