Study on Precipitation of Astaxanthin in Supercritical Fluid

As health hazards of synthetic pigments are continuously found, more and more natural food pigments have been applied to the food industry. Astaxanthin is one of carotenoids that have been widely used in the food, cosmetic and pharmaceutical industries as natural colorants. In this paper, the micronization of astaxanthin in dichloromethane via the solution enhanced dispersion by supercritical fluids through prefilming atomization (SEDS-PA) process has been successfully performed. Morphologies and particle sizes (PSs) of the astaxanthin microparticles were analyzed by scanning electron microscopy (SEM). The results of micronization show that astaxanthin crystals with PSs about 20–30 µm have successfully been micronized to the microparticles with PSs about 0.5–6.0 µm by the SEDS-PA process. The effect of experimental variables on micronization of the astaxanthin has been studied. With the increase of initial solution concentration, the PSs of astaxanthin microparticles decrease initially, then increase. With the increase of solution flow rate and temperature, the PSs of astaxanthin microparticles increase. With the increase of pressure, the PSs of astaxanthin microparticles decrease. The nubbly particles were obtained in SEDS-PA process, and the crystallinity change of astaxanthin was showed by X-ray powder diffraction patterns (XRD).

The micronization of astaxanthin in supercritical fluid has been successfully performed by the SEDS-PA process. Astaxanthin crystals about 20–30 µm have successfully been micronized to 0.5–6.0 µm. The effect of experimental variables on micronization of the astaxanthin has been studied, and the crystallinity change of astaxanthin was shown by X-ray powder diffraction patterns (XRD).Figure optionsDownload as PowerPoint slide