Abstract: Lotus seedpod oligomeric procyanidin (LSOPC)-loaded nanoliposome was prepared by reverse-phase evaporation method in combination with ultrasonic treatment. The preparation process was optimized and the stability and antioxidant activity of the nanoliposome were determined in this research. The results indicated that the optimal parameters of the preparation process were as follows: ratio of phosphatidylcholine and cholesterol, 3:1; LSOPC concentration, 0.33 mg/mL; and Tween 80 concentration, 16.7 mg/mL. The average particle size of the nanoliposome prepared under these conditions was (35.57 ± 0.08) nm, and the polydispersity index was 0.153 ± 0.01. The highest encapsulation efficiency of (71.97 ± 0.42)% was achieved at an LSOPC concentration of 1%. The spherical vesicle structure was observed by transmission electron microscopy, and the nanoliposome was found to be stable at low temperature. Low concentrations of glucose and sucrose had little impact on the size of LSOPC nanoliposome. Fe3+, Cu2+, Zn2+, and Pb2+ affected its size. Compared with the nanoliposome, the 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt scavenging activity and ferric reducing power of LSOPC solution dropped significantly after being stored at 4 ℃ for a week. LSOPC nanoliposome had higher total antioxidant capacity, as measured by oxygen radical absorbance capacity (ORAC), than LSOPC solution.

Key words: lotus seedpod oligomeric procyanidins, nanoliposome, stability, antioxidant activity