Astaxanthin (0.08% w/w) was dissolved in a mixture of 62% w/w acetone and 38% w/w dichloromethane, added to the aqueous phase at a ratio of 11.5% w/w organic/aqueous phase, and homogenised with a conventional homogeniser (Silverson, L4R, Buckinghamshire, UK) at 5000 rpm for 5 min