Soy Soluble Polysaccharide as a Nanocarrier for Curcumin

The complexation between soy soluble polysaccharide (SSPS) and curcumin at pH 7.0 and 4.0, as well as some physicochemical characteristics of the resultant complexes, was investigated. The encapsulation efficiency and loading amount of curcumin in the complexes at pH 4.0 reached 67.3% and 4.49 μg/mg SSPS, respectively. Ethanol-induced denaturation and structural unfolding of the protein fraction in SSPS was essential for complex formation. The complexation with curcumin resulted in aggregation of SSPS and the subsequent formation of compacted nanoparticles with curcumin as the core. The complexation greatly improved the heat stability and in vitro bioaccessibility of curcumin. In general, the encapsulation efficiency, heat stability, and bioaccessibility of curcumin in the complexes at pH 4.0 were better than those at pH 7.0. The findings are of importance for the development of food grade nanovehicles for enhanced water solubility, stability, and bioaccessibility of hydrophobic bioactives.