Rheological properties of astaxanthin oleoresins and their derived products

Abstract This chapter focuses on viscosity studies that have been carried out with 5% and 10% astaxanthin oleoresins (AO) and oil-water macroemulsion, and “red meal” product, which is a pulp obtained from the biomass disruption in the lipid medium with a concentration of 1.5% astaxanthin, prepared for animal feed. All these products are produced from the biomass of Haematococcus pluvialis microalgae. The following aspects relating to different models used only for AO-5% are discussed: power, Herschel-Bulkley, Bingham, Casson, and Mizrahi-Berk at different temperatures. We highlighted in each the flow behavior index (n), consistency index (K), and yield stress (ko), using statistical tools for model validation: estimation standard error (SEE), mean absolute error (MAE), chi-square (χ2), root mean square mean (RMSE), and determination coefficient (R2), with better fitting for power law model. In the rest of the products, only this model was used, obtaining the results of the apparent viscosities (ηap) and activation energies (Ea) for different temperatures.