Effects of phytosterols on antioxidant activities of mulberry anthocyanin liposomes
The molecular structure of phytosterols is similar to cholesterol.As membrane structure regulators,phytosterols can regu-late the structural properties of liposome membrane while avoiding the negative effects of cholesterol intake.In this study,phytosterols were used to replace cholesterol,and mulberry anthocyanin liposomes were prepared by thin film dispersion-ultrasonic method.The physical and chemical indexes of liposomes were evaluated by encapsulation rate,particle size,potential and microscopic morphology.The effects of phytosterols on pH stability and antioxidant activity of liposomes were also investigated.The results showed that,similar to the cholesterol liposomes,the addition of phytosterol could be able to obtain mulberry anthocyanin liposomes with small particle size,good dispersion and high encapsulation efficiency.When the addition level of β-sitosterol was 26%of the lecithin mass,the DPPH scavenging ability of mul-berry anthocyanin liposomes after storage was 1.6 times more than that of the liposomes with an equal amount of cholesterol.The ORAC absorption capacity of phytosterol liposomes before and after storage was superior to that of cholesterol liposomes.And the ORAC values of mixed phytosterol liposomes did not change much when the ORAC values of cholesterol liposomes decreased 2.42~3.65 times after stor-age.In conclusion,the use of phytosterol instead of cholesterol to prepare liposomes of mulberry anthocyanin can produce more stable mul-berry anthocyanin liposomes with good antioxidant activity,which can provide a theoretical basis for the construction of phytosterol lipo-somes loaded with bioactive substances.