Characterization of Green Tea Extract Loaded Liposomes

Green tea extract was encapsulated into liposomes to enhance bioavailability and stability of catechins that are the main bioactive compounds and to protect the functional properties of green tea. Green tea extract (w/w 0.1%) was encapsulated by dispersing 1 % (w/w) soy lecithin through high pressure homogenization and ultrasonication techniques. Effect of homogenization type and pH of the dispersing medium was investigated. Mean particle size, total phenolic content by FolinCiocalteu Method and antioxidant activity by DPPH Radical Scavenging method and Ferric Reducing-Antioxidant Power (FRAP) method, and transmission electron microscopy (TEM) experiments were conducted for characterizing liposomes. Change in the mean particle size of liposomes between first day and one month storage time was not found significant (p > 0.05) for the liposomes prepared by distilled water (pH 6.5) by microfluidizer and ultrasonication while there was significant difference on the mean particle sizes of liposomes (p ≤ 0.05) for the samples prepared in acetate buffer (pH:3.8) for the 2 homogenization techniques. Difference in antioxidant activity measured by DPPH Radical Scavenging method between first and final day of one month storage time of liposomes was not significant (p > 0.05) for the liposomes prepared by microfluidizer in distilled water and acetate buffer while significant difference (p ≤ 0.05) was found in antioxidant activity for samples prepared by ultrasonication in both medium