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.