Micro/nano emulsion delivery systems: Effects of potato protein/chitosan complex on the stability, oxidizability, digestibility and β - carotene release characteristics of the emulsion

Abstract

The stability, antioxidant activity, digestibility and β - carotene sustained - release mechanism of Pickering emulsion stabilized by potato protein/chitosan (PP/CS) complex were investigated. The results exhibited that the isoelectric point of PP increased from 4.30 to 6.50 and 7.00 after adding 0.2% and 0.4% CS to improve its surface hydrophilicity, leading to a uniform dispersion of PP. Simultaneously, the average particle size of the emulsion stabilized by the PP showed a decrease from 5102.50 nm to 784.90 and 1268.50 nm and zeta - potential of the emulsion stabilized by the PP exhibited an increase from 40.63 to 48.50 and 53.73 mV after adding 0.2% and 0.4% CS to improve the stability of the emulsion. In addition, the emulsion stabilized by the PP/CS complex was found to have a smaller storage modulus (G′), loss modulus(G″), apparent viscosity and better physical stability, which was less affected by storage time, temperature and salt ion concentration. Moreover, the emulsion stabilized by the PP/CS complex exhibited better oxidation resistance. Furthermore, the emulsion stabilized by the PP/CS complex showed good anti-digestibility and slowed the sustained release rate of β - carotene. These results will provide a theoretical basis for the application of a novel food emulsifier PP/CS complex in nano - colloid delivery system.