Preparation and characterization of sodium selenite/sodium alginate microcapsules

Microencapsulation was an effective method to prevent the sodium selenite (Na2SeO3) from being oxidized by environmental factors. By using sodium alginate as the shell, Nano-calcium carbonate as the cross linker, Na2SeO3 was encapsulated by emulsification/internal gelation to obtain sodium selenite/ sodium alginate microcapsules (SSSAM). The composition and structure were characterized by Fourier infrared (FTIR) and X-ray diffraction (XRD), respectively. The result showed that Na2SeO3 was embedded into SSSAM in the form of amorphous state. When the mass ratio of Nano-CaCO3 was 1/2, the oil-water volume ratio was 4∶1, Span 80 mass fraction 3%, emulsification for 40 min, cross-linking for 15 min, the loading content (LC) of Na2SeO3 and encapsulation efficiency (EE) of SSSAM were 16.2% and 52.7%, respectively.