Stability, bioactivity, and bioaccessibility of fucoxanthin in zein-caseinate composite nanoparticles fabricated at neutral pH by antisolvent precipitation

In this study, caseinate-stabilized zein particles (zein-Cas) were developed at neutral pH to encapsulate fucoxanthin (FX) using a simple antisolvent precipitation method. Fluorescence results indicated that zein or Cas interact with fucoxanthin by hydrophobic contacts with a binding constant magnitude of 105 M−1. The presence of proteins resulted in altering the FX precipitates from irregular shape to spherical shape at higher zein proportions, as confirmed by transmission electron microscopy. The average particle size of FX-loaded zein-Cas particles was below 150 nm (100 to 130 nm) with negative surface charge (−30 to −35 mV). The encapsulated FX showed higher stability, antioxidant activity and antiproliferative activity than free FX. Besides, the bioaccessibility of encapsulated FX was appreciably higher than it was not encapsulated. These results demonstrated that FX-loaded zein-Cas nanoparticles could enable the application of FX in functional foods and beverages, as well as in pharmaceutical products.