Some physical characteristics of the O/W macroemulsion of oleoresin of astaxanthin obtained from biomass of Haematococcus pluvialis

Abstract

Macroemulsions facilitate the solubilization, stability, bioaccessibility, and bioactivity of compounds with low solubility, as is the case of the emulsion developed from astaxanthin oleoresin (10%). In this study, some characteristics of the physical behavior of the macroemulsion with astaxanthin oleoresin that are in close relationship with stability were determined. One of them was the viscosity at 5, 10, 20 and 30°C. Another, corresponded to observing the size variation of the micelles, observed under the microscope for 8 days and finally, the color was determined in CIEL*a*b* system for 34 days. The results showed that the macroemulsion behaved like a shear thinning fluid up to 20°C, becoming a shear thickening fluid at 30° C. In addition, the macroemulsion presented stability in the color as time elapsed; observing some slight variations that may be due to flocculation and coalescence. Both affect the viscosity at low temperatures.