Abstract:

As a natural and efficient antioxidant, carvacrol has a good antibacterial and antioxidant properties. But the carvacrol has lower bioavailability than some neurotrophic substance due to its poor water solubility. To solve this problem, the gliadin/pectin-carvacrol were prepared by anti solvent method, using gliadin as the material, and pectin as a crosslinker. The effects of different mass ratios of gliadin and pectin, different mass ratios of gliadin and carvacrol, pH value, salt ion concentration and storage time on the stability of composite nanoparticles were investigated by the means of particle size analyzer and optical photographs. The results show that the particle size of the composite nanoparticles is 179.23 nm, the polydispersity index （PDI） is 0.21, and the Zeta-potential is -36.42 mV with m（gliadin） ∶m（pectin）=1∶1.5. Moreover, the encapsulation efficiency is 85.23% with the m（gliadin） ∶m（carvacrol）=10∶1. When the pH=3.0-9.0 and salt ion concentration is lower than 50 mmol/L, the composite nanoparticles loaded with carvacrol have a good stability, and the storage experiment shows that the system is uniform and stable within 28 days. The results of transmission electron microscopy also show that pectin and gliadin formed a stable spherical structure through the electrostatic interaction. In addition, the antioxidant experiments show that the composite nanoparticles loaded with carvacrol can effectively eliminate free radicals and prevent food oxidation, and the IC₅₀ of DPPH radical scavenging activity is （13.21±0.81） μg/mL, which has a good application prospect in the field of food preservation and packaging.

Key words: gliadin, pectin, nanoparticle, carvacrol