Novel astaxanthin extraction from Haematococcus pluvialis using cell permeabilising ionic liquids
Haematococcus pluvialis (H. pluvialis) is a natural source of the food colorant astaxanthin. It is characterised by a thick resistant cell wall composed of a non-hydrolysable biopolymer, sporopollenin. High energy-consuming mechanical disruption is required to improve the extractability of astaxanthin. As opposed to that, this study uses a novel technology with ionic liquids (ILs) to permeabilise the Haematococcal cyst cell at mild temperatures and improve the extraction of astaxanthin. The study shows that ≥70% astaxanthin can be extracted from intact H. pluvialis cells using 1-ethyl-3-methylimidazolium di-butylphosphate (EMIM DBP) at a concentration of 40% w/w in a water solution and a temperature of 45 °C. Ionic liquids serve as a promising pre-treatment step for extraction of pigments from intact H. pluvialis cells. The results obtained open new avenues for processing of algal biomass.