Novel functional carriers based on Spirulina protein for the delivery of curcumin with improved stability and antioxidant efficiency

The potential of sustainably sourced Spirulina protein (SP), and SP nanoparticles (SPNP) obtained by heating gelation and ultrasound treatment as functional carriers for curcumin (Cur) was studied. The antioxidant activity, encapsulation performance, stability and digestive properties of the delivery system were analyzed. Compared with SP, SPNP exhibited higher hydrophobicity, and its antioxidant capacity was enhanced due to increased exposure of chromophores. The encapsulation performance of Cur-loaded complexes was influenced by the protein-Cur mass ratio, and the encapsulation efficiency of SPNP was significantly higher than that of SP (p < 0.05). Because of the better binding affinity, SPNP-Cur complexes showed improved thermal stability and UV protection effect. SP and SPNP all exhibited antioxidant synergism with Cur, and the antioxidant efficiency was closely related to pH, dissociating solvents, UV irradiation and digestion. The bioaccessibility of Cur was also greatly improved. It suggests that Spirulina protein may be an ideal carrier for delivering nutraceutical compounds.