Food-based biomaterials: pH-responsive alginate/gellan gum/carboxymethyl cellulose hydrogel beads for lactoferrin delivery

The present study utilizes a combination of sodium alginate (Alg), gellan gum (GG), and sodium carboxymethyl cellulose (CMC) to fabricate a ternary composite hydrogel system to encapsulate and release lactoferrin (LF). Rheological properties as well as extensive microscopy and spectroscopy characterization are performed on these materials demonstrating that the physical properties of the resultant hydrogels, such as particle size, water content, gray value, and shrinkage rate were related to the concentration of Alg. In addition, most of these hydrogels were found to have reticulated shells and inner laminar structures assembled based on hydrogen bonding and electrostatic forces. Furthermore, the encapsulation efficiency of LF in hydrogels ranged from 78.3 ± 0.3 to 83.5 ± 0.2 %. Notably, a small amount of encapsulated LF was released from the hydrogel beads in an acid environment (up to 2.2 ± 0.3 % in 2 h), while a controlled release manner was found to take place in an alkaline environment. This phenomenon indicated the potential of these hydrogels as promising matrices for bioactive compound loading and adsorption. The release mechanism varied from Alg concentration suggesting the tunable and versatile properties of this ternary composite hydrogel system. Our findings identify the potential of Alg-GG-CMC hydrogel as a delivery system suitable for various applications in the food industry.