Lutein transport systems loaded with rice protein-based self-assembled nanoparticles

The solubility of lutein (Lut) was improved through the construction of encapsulated nanoparticles using rice protein hydrolysates (RPH) as nanocarriers. The effects of rice protein (RP) with three different degrees of hydrolysis (DH) including low (2%), medium (4%) and high (8%), with RPH protein concentrations (1, 2, 5 and 10 mg/mL) and Lut levels (0.25-1.5 mg/mL) on the preparation of Lut-RPH were studied using an antisolvent method. Particle size, zeta-potential, loading content (LC), encapsulation efficiency (EE) and morphology were analysed to characterize Lut-RPH. The interaction mechanism between Lut and RPH was also investigated. The EE of Lut nanoparticles encapsulated using RPH with three DH were 94.1, 89.8 and 90.5%, respectively, while LC was 23.5, 22.4 and 22.6%, respectively. The interaction between Lut and RPH suggested that the RPH fluorescence was gradually quenched by the addition of Lut in a dose-dependent manner. The higher binding constants K-a and more binding sites of Lut-RPH than that of Lut-RP suggested there was a strong binding force between RPH and Lut. These experiments confirmed the sucess of the green and safe Lut-RPH process, which will provide important information for the future application of Lut in nutritional fortified foods, supplements and drug delivery.