Abstract: The effects of the mass ratio of soybean lecithin to cholesterol, the dosage of Tween-80 and homogenization pressure on the mean particle size and encapsulation efficiency of docosahexaenoic acid (DHA)-rich algae oil liposomes prepared by high-pressure microfluidization were studied. Using a combination of one-factor-at-a-time (OFAT) method and statistical response surface methodology (RSM), the optimal preparation parameters were determined as follows: soy lecithin concentration 20 mg/mL, lecithin to DHA algae oil mass ratio 4:1, lecithin to cholesterol mass ratio 11.9:1, Tween-80 dosage 15% (relative to soy lecithin), homogenization pressure 138 MPa, and five cycles of homogenization. The mean particle size, polydispersity index and encapsulation efficiency of the algal oil liposomes prepared under these conditions were (59.35 ± 3.05) nm, 0.189 ± 0.025, and (94.2 ± 2.9)%, respectively. By transmission electron microscope (TEM), it was observed that the liposomes were spherical and uniformly distributed. Differential scanning calorimetric (DSC) analysis showed that high-pressure microfluidizer homogenization improved the phase transition temperature of the liposomes effectively. Moreover, the liposomes treated with high-pressure microfluidizer homogenization had good physical, storage and oxidation stability.

Key words: docosahexaenoic acid-rich algae oil; liposomes; high-pressure microfluidization; stability