Extraction of astaxanthin from Haematococcus pluvialis microalgae using a biphasic solvent system

Abstract

This study focused on the effect of a two-solvent immiscible system consisting of 0.2M H2SO4 solution and ethyl acetate - hexane mixture for rapid extraction and recovery of astaxanthin and its derivatives from Haematococcus pluvialis (H. pluvialis). The effect of changing the composition of solvent in the two-phase liquid system on the ability to extract astaxanthin was evaluated and then, the ratio of the organic solvent mixture was optimized. The results under the survey conditions showed that the maximum extraction efficiency reached 95.02 ± 1.88% with the organic solvent volume/microalgae mass ratio was 12 mL/g when hexane/ethyl acetate ratio was 1/1, showcase significantly higher than the single solvent extraction efficiency. The results of the optimal function calculation using the centered combination method gave an expected organic solvent volume/microalgae mass ratio was 9.563 mL/g with the hexane ratio in the organic solvent was 61.31%, the expected efficiency achieved was 83.26%. In addition, the study also showed that the concentration of H2SO4 only affects the process of cell wall disruption and have none affecting the dissolution process. Plus, the dissolution reaction of astaxanthin from H. pluvialis microalgae is a first-order chemical reaction.