Nanoparticles based on sodium alginate and β-conglycinin: Self-assembly and delivery of Phyllanthus urinaria phenolic compounds

Abstract

Nanoparticles based on sodium alginate (SA) and β-conglycinin (7S) were self-assembled according to the electrostatic interaction principle. The self-assembly parameters optimized by response surface methodology were total concentration of 7S and SA of 6.0 mg/ml, 7S to SA mass ratio of 1.85:1, and pH of 2.5. Phyllanthus urinaria phenolic compounds were loaded into the nanoparticles according to the optimized parameters. The phenolic compounds-loaded nanoparticles characterized by scanning electron microscopy and particle size analyzer showed that they had a spherical shape with the average size was around 125 nm. Infrared spectroscopy analyses indicated that there were intramolecular hydrogen bonds in the nanoparticles, and the phenolic compounds were successfully encapsulated. The phenolic compounds released from the nanoparticles had good antioxidant activity, and their cumulative release percentage at pH 7.4 was higher than that at pH 1.2. The release kinetics of phenolic compounds showed a pH-dependent release profile and a Fickian diffusion mechanism. Practical applications: Phenolic compounds from Phyllanthus urinaria have excellent bioactivities and have been proven that there are numerous benefits for body. However, the applications of the phenolic compounds are limited because of their chemical instability against environmental conditions. Nanoencapsulation technology is a promising approach to solve this problem. This work aimed at encapsulating the phenolic compounds into nanoparticles by self-assembly method for the improvement of bioavailability and the applications of food industry.