Conclusion
The obtained extracts of green tea were very effective to prevent of the
primary and secondary oxidation products in the studied canola oil.
Green tea extract both free and incorporated in liposome showed a good
antioxidant activity. The 600 mg/L concentration of green tea extract
had stronger antioxidant properties than BHT and other green tea
concentrations that its reason can be extract polyphenols. In addition
to, the results determined green tea extract liposomes possessed
powerful antioxidant activity that showed liposome structure caused to
improve the stability of tea polyphenol. The increasing storage time
caused to upward trend of canola oil oxidation. While the increasing
green tea extract concentration from 200 to 600 mg/L had a significant
impact in preventing of oxidation process (P≤0.05) but green tea extract
in concentration of 1000 mg/L did not show any strong antioxidant
activity and causing delay in canola oil oxidation. This study
determined natural antioxidants such as green tea extract can be a good
alternative instead of synthetic antioxidants.