Abstract:

Coix seed oil liposomes were prepared by a technology of combined ethanol injection and ultrasonic. An orthogonal array design involving 9 experiments of four crucial factors at 3 levels was employed to obtain the highest embedding rate. The morphology of coix seed oil liposomes was observed under SEM, their particle size and Zeta potential were measured, and their storage stability was evaluated in terms of appearance, T500nm, pH value and retention rate of coix seed oil. The optimum preparation conditions were as following: concentration of lecithin 20 mg/ml, ratio of lecithin to coix seed oil to cholesterol 3:2:1 (m/m), and using phosphate buffer solution (pH 6.7) as the aqueous phase. The coix seed oil liposomes prepared under the above conditions were observed to be uniform and round with a mean particle size of 207.4 nm and their Zeta potential and embdeding efficiency were － 26.4 mV and 72.48%, respectively. The stability of bilayer structure of coix seed oil liposomes is related to storage temperature, and they have the longest storage life in a light-avoiding environment at 4 ℃.

Key words: coix seed oil (CSO), liposomes, encapsulation efficiency, quality evaluation