Evaluation of antioxidant stability of arbutin and pyrus boissieriana Buhse leaf extract

With regard to the importance of antioxidants in foods, cosmetics and pharmaceutics, there are several studies on
natural resources for finding rich sources of antioxidants and their role in protecting the body against oxidative
stress injuries. The purpose of this study was to investigate the antioxidant stability of arbutin and the Pyrus
boissieriana buhse Leaf extract and their effects on lipid oxidation in different conditions of temperature and
time. Arbutin and the Pyrus boissieriana buhse Leaf extract were stored for 14 days in the different conditions of
temperature including room, refrigerator and freezer. Total phenolic compounds were measured by the folinciocaltea method. Flavonoid compounds were evaluated by aluminum chloride method. Their total antioxidant
activity was measured by FRAP (ferric reducing antioxidant power) method and their protection effect on lipid
oxidation was measured by TBARS (thiobarbituric acid reactant substances) method. Also, the amount of
sustainability for peroxide activities was measured by TMB (Tetra Methyl Benzedrine) method. Polyphenol
formed 1.96 mg/g dry weight of Pyrus boissieriana buhse Leaf extract and the amount of flavonoid complex was
0.125 mg/g dry weight of Pyrus boissieriana buhse Leaf extract. The amount of FRAP was decreased by
increasing temperature and time. The amount of lipid oxidation had increased in all samples with time (0-14).
The stability of peroxide activities decreased in the different conditions of temperature and time. The results of
this study show the existence of antioxidant activities with higher stability in storage time and the protective
effect of arbutin and Pyrus boissieriana buhse Leaf extract on lipid oxidation. Therefore, using arbutin and
Pyrus boissieriana buhse Leaf extract as a natural resource of antioxidant is suggested for substituting synthetic
antioxidants.