Curcumin delivery based on bovine bone protein hydrolysate–flaxseed gum emulsion carrier: a strategy for stability enhancement and bioaccessibility improvement

Abstract Background Curcumin is a natural polyphenolic compound that exhibits various biological activities. However, its low solubility in water and instability significantly limit its potential application in the food industry. Therefore, appropriate encapsulation systems are required to address these limitations. Results This study initially examined the structural changes of bovine bone protein hydrolysate (BBPH) after its combination with flaxseed gum (FG) and subsequently evaluated the encapsulation properties of BBPH–FG emulsions for curcumin. The results showed that, in an aqueous solution, BBPH and FG formed a complex through hydrophobic and electrostatic interactions, which significantly enhanced the surface hydrophobicity of the BBPH and improved its thermal stability (145.1 °C). Encapsulation of curcumin in the emulsions revealed that its incorporation had a minimal effect on the overall stability of the BBPH–FG emulsion system. The encapsulation efficiency reached 77.51% when the curcumin concentration was 0.2%. At this concentration, the curcumin emulsions demonstrated scavenging efficiencies of 62.69%, 86.98% and 79.98% for OH radicals, DPPH radicals and ABTS radicals, respectively. Furthermore, the results from in vitro simulated digestion experiments indicated that the digestive stability and bioaccessibility of curcumin following emulsion encapsulation were 77.47% and 67.36%, respectively, both of which were markedly higher than those of curcumin dissolved in the oil phase. Conclusion This study demonstrates that encapsulation via a BBPH–FG emulsion system can significantly enhance the stability and bioaccessibility of curcumin during in vitro simulated digestion. These findings provide valuable insights into the construction of food‐grade emulsion delivery systems and offer potential avenues for expanding the applications of curcumin. © 2025 Society of Chemical Industry.