Characteristics of vitamin C immobilized particles and sodium alginate beads containing immobilized particles.

This paper reports the properties of vitamin C encapsulated sodium alginate beads prepared by an alternative approach. The alternative encapsulation process mainly involves immobilization of vitamin C in hydrated zinc oxide layers and encapsulation of prepared immobilized particles in sodium alginate bead. The immobilization of vitamin C in hydrated zinc oxide layers was achieved by a coprecipitation process. Fourier transform infrared (FTIR) spectroscopy showed that the vitamin C was found to be stable after its immobilization. X-ray diffraction (XRD) studies revealed that anionic vitamin C molecules are adsorbed between positively charged zinc hydroxide layers with a 1:1 layer sequence, since well-defined change in basal spacing was observed. Well-defined change in surface morphology was observed by scanning electron microscopy (SEM) when vitamin C immobilized particles are encapsulated in sodium alginate bead. The biological activity of vitamin C was retained, even after its immobilization which was confirmed by 4-dihydroxy-L-phenylalanine (L-DOPA) oxidase inhibition and free radical scavenging activity studies. The release rate of vitamin C from immobilized particles and beads was sustained through an ion exchange process. A higher amount of stable vitamin C was recovered from the bead when compared to neat vitamin C itself.