Characterization and embedding potential of bovine serum albumin cold-set gel induced by glucono-δ-lactone and sodium chloride

Bovine serum albumin (BSA) was induced to form cold-set gel by using glucono-delta-lactone (GDL) and sodium chloride (NaCl), and characteristics of the gel and its embedding potential to bioactive molecules were investigated. The results from texture analyzer indicated that hardness and springiness of BSA cold-set gel were improved by increasing GDL or NaCl, but the gel with lower concentration of GDL (1.0%) and NaCl (0.2 M) had better water holding capacity (WHC). GDL had a significant influence on storage modulus (G') and loss modulus (G '') but it did not appear to be applicable to NaCl. Light transmittance at 500 nm and average particle size were used to characterize formation of BSA cold-set gel as pH values decreased, and the results suggested that BSA molecules had aggregated at the pH value of the gel point. Microstructure and fractal analysis from confocal laser scanning microscope (CLSM) further suggested that electrostatic and hydrophobic interaction played important roles in the formation of the cold-set gel and it could be deduced that structure and properties of the gel were closely related to the forces. BSA cold-set gel showed an excellent embedding performance to encapsulate bioactive molecules (used quercetin as representative), and achieved effective slow-release action, especially in simulated intestinal juice of pH 7.5. BSA cold-set gel may have important potential application in encapsulation, protection, delivery and controlled-release of some fragile bioactive components, so the research provides a theoretical basis for its application.