Stability and bioactivity of carotenoids from Synechococcus sp. PCC 7002 in Zein/NaCas/Gum Arabic composite nanoparticles fabricated by pH adjustment and heat treatment antisolvent precipitation

Abstract

Abstract Encapsulation systems present a positive alternative to protect bioactive ingredients and expand their application in the food industry. In this study, Zein/NaCas/Gum Arabic composite nanoparticles were first fabricated by heat treatment of electrostatic protein-polysaccharide complexes to encapsulate carotenoids from Synechococcus sp. PCC 7002. The system could be self-assembled to spherical shape (less than 150\xa0nm) particles with uniform distribution (polydispersity index around 0.2) and high negative charge (about −39.23\xa0mV) after heat treatment. The encapsulation efficiency was higher than 80%, more importantly, and heating did not significantly reduce the encapsulation efficiency of carotenoids. Fluorescence spectra indicated that the zein could spontaneously combine with carotenoids. Besides, infrared spectroscopy analysis showed that hydrogen bonding, hydrophobic and electrostatic interactions were the dominant forces forming composite nanoparticles. Furthermore, these carotenoids-loaded nanoparticles showed excellent physical stability, excellent chemical antioxidant properties, and non-toxicity in Caco-2\xa0cells with heat treatment. Encapsulation of carotenoids in the composite nanoparticles by pH adjustment and heat treatment antisolvent precipitation not only showed good re-dispensability but also provided controlled release under simulated gastrointestinal conditions. These results suggested that Zein/NaCas/Gum Arabic composite nanoparticles could be used as a promising carotenoids delivery system.