Effect of CO2 Flow Rate on the Extraction of Astaxanthin and Fatty Acids from Haematococcus pluvialis Using Supercritical Fluid Technology.

Haematococcus pluvialis is the largest producer of natural astaxanthin in the world. Astaxanthin is a bioactive compound used in food, feed, nutraceutics, and cosmetics. In this study, astaxanthin extraction from H. pluvialis by supercritical fluid extraction was evaluated. The effects of temperature (40 and 50 °C), pressure (40 and 50 MPa), and CO2 flow rate (2 and 4 L/min) were investigated. The results showed that the highest astaxanthin recovery was obtained at 50 °C/50 MPa and the CO2 flow rates evaluated had no significant effect. It was possible to achieve astaxanthin recoveries of 95% after 175 min for a CO2 flow rate of 2 L/min, and 95 min for CO2 flow rate of 4 L/min. The ω-6/ω-3 ratios obtained were similar in all conditions, reaching 0.87, demonstrating that the extracts from H. pluvialis by SFE are rich in unsaturated fatty acids (UFA) which increases their positive effects when used as a functional ingredient in food.

Isotonic Beverage Pigmented with Water-Dispersible Emulsion from Astaxanthin Oleoresin.

Astaxanthin is a powerful antioxidant, because it neutralizes free radicals and plays a vital role in the prevention of human diseases. The objective of this work was to develop an isotonic beverage (IB) of orange-red color, using an astaxanthin oleoresin emulsion (AOE) that is dispersible in water. This was carried out in order to simulate the color of commercial isotonic beverages (CIB) prepared from artificial pigments. The size of the AOE micelles ranged from 0.15 to 7.60 µm2. The color difference (ΔE) was similar for the samples exposed to dark as well as light conditions. The samples subjected to light stress showed pigment degradation after seven days, followed by a decrease in the concentration of astaxanthin; whereas, the samples exposed to dark conditions remained stable for seven days and then showed a decrease in the concentration of astaxanthin (this decrease ranged from 65% to 76% when compared to the initial content) after a period of 91 days. For the astaxanthin oleoresin (AO) and AOE, the oxygen radical absorbance capacity (ORAC) values reached 5224 and 1968 µmol of trolox equivalents (TE)/100 g, respectively. When exposed to light conditions, the addition of AOE in the IB led to its rapid degradation, while it remained stable in the samples exposed to the dark conditions.