Improvement in storage stability and resveratrol retention by fabrication of hollow zein-chitosan composite particles

Solid and hollow particles based on zein have been prepared for the encapsulation of bioactive components. Hollow particles have many advantages over their solid counterpart, due to increased surface area, low density, and sustained release, emerged as a promising delivery system for polyphenols. It is necessary to improve the stability of zein particles for the encapsulation of bioactive components. The current work aims to prepare hollow zein particles by employing chitosan coating and explore the potential of the composite particles for the encapsulation and protection of resveratrol, a natural polyphenol. Hollow zein (HZ) and zein-chitosan (HZ-CH) particles were characterized in terms of size, surface charge, morphological structure, particle yield and antioxidant activity. Encapsulation of resveratrol in the zein matrix was studied by the help of fluorescence, infrared and X-ray diffraction techniques. The composite particles were also subjected to storage and in vitro digestion. Particle yield was greater than 90% when the concentrations of chitosan were greater than 0.02%. HZ-CH particles were positively charged and bigger in size as compare to HZ particles. Resveratrol entrapment caused an apparent increase in the size of the particles. The highest encapsulation efficiency and loading capacity of resveratrol were 91% and 14% in the hydrophobic zein shell of HZ-CH particles, respectively. The chitosan coating improved the storage and digestion stability of resveratrol-loaded hollow zein particles and the storage stability of encapsulated resveratrol and exhibited a sustained in vitro release of resveratrol. Therefore, the hollow zein composite particles could be used as an efficient delivery system for resveratrol in the development of functional foods.