Thiobarbituric Acid Reactive Substances (TBARS)
TBA test is an index of secondary oxidation products which can use for monitoring vegetable oils oxidation (Shahidi & Wanasundara., 1997). In this research, the addition green tea extracts as free and encapsulated in liposome had a significantly affect (P≤0.05) in reducing TBARS formation as compared control canola oils that have shown in Table 4. Among green tea extracts, liposomes containing extracts had better efficiency to decrease canola oil oxidation. The lowest TBA value was observed at 600 mg/L concentration of liposomal extract of green tea. Zokti et al. reported, encapsulated green tea extracts had the higher antioxidant activity than free green tea extract in mango drink (Zokti et al., 2016). Free green tea extract at concentration of 600 mg/L and liposomal extract at 200, 600 and 1000 mg/L showed higher efficiency in compare to BHT. The obtained results are in agreement with other reports (Semwal & Arya., 2001; Hassan et al., 2013). They found TBA values, respectively, on the sunflower and canola oils, increased during storage time.