Efficient supercritical carbon dioxide extraction of astaxanthin from Hematococcus pluvialis at high pressure

Abstract

Astaxanthin derived from Hematococcus pluvialis (H. pluvialis) exhibits potent capacity in scavenging free radicals and quenching active oxygen. However, the conventional extraction of Astaxanthin from H. pluvialis involves the use of a substantial amount of organic reagents, leading to environmental pollution and low extraction efficiency. In this work, a high-pressure supercritical CO2 extraction (H-SFE) was applied to extract astaxanthin from H. pluvialis. Influential parameters of H-SFE were optimized by single factor, orthogonal test and kinetics experiments. Extraction pressure is a critical component influencing the extraction efficiency of SFE. Increased pressure results in increased supercritical CO2 density and thus increased solubility of substances and enhanced component extraction. The extraction yield of astaxanthin at 65MPa was 1.25 times and 2.32 times higher than that at 45MPa and 25MPa, respectively. The H-SFE extraction yield of astaxanthin was 20%-70% higher than that of ultrasonic-assisted extraction (UAE) and organic solvent extraction (OSE).