RESUMO
This study aimed to prepare carrageenan/sodium alginate double-stabilized layers of zein nanoparticles loaded with daidzein using ultrasound technology to investigate the effect of ultrasound treatment on the stability of composite nanoparticles and encapsulation of daidzein. Compared with composite nanoparticles without ultrasound treatment, the encapsulation efficiency of nanoparticles was increased (90.36 %) after ultrasound treatment (320 W, 15 min). Ultrasound treatment reduced the particle size and PDI of nanoparticles and improved the stability and solubility of nanoparticles. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) revealed that the nanoparticles treated with ultrasound were smooth spherical and uniformly distributed. Fourier transform infrared spectroscopy (FTIR) results showed that the main forces that form nanoparticles are hydrogen bonding, electrostatic interactions and hydrophobic interactions. Fluorescence and CD chromatography showed that ultrasound treatment alters the secondary structure of zein and maintains nanoparticle stability. Encapsulation of daidzein in nanocarriers with ultrasound treatment can effectively scavenge DPPH and ABTS free radicals, improve antioxidant activity, and realize the slow release of daidzein in the gastrointestinal tract. The results showed that ultrasonication helps the construction of hydrophobic bioactives delivery carriers and provides better protection for unstable bioactives.