A Comparison between the Antioxidant Strength of the Fresh and Stale Allium sativum (Garlic) Extracts

Fruits and vegetables are considered as the source of antioxidant and the factor of destroying reactive oxygen species. The effect of this antioxidant might decrease in time. This study was aimed at examining and comparing the antioxidant effect and the level of phenolic and flavonoid compounds as well as allicin level, between fresh and three-month stale Allium sativum (garlic). In an experimental study, the ethanolic extract of bushes of fresh and three-month-old Allium sativum was prepared and their antioxidant activities were assessed in linoleic acid and β-carotene linoleate system. The amount of phenolic compounds was measured by Folin-Ciocalteumethod, based on gallic acid; the amount of flavonol and flavonoid compounds by aluminum chloride base on rutin base; and the amount of allicinby spectrophotometry method. SPSS-15 Software and t-statistic tests were used to analyze the mean difference between the results of two groups and p<0.05 was considered as significant. The efficiency of fresh garlic (35.36) in inhibiting the oxidation was higher (p<0.05) comparing to three-month dated Allium sativum (10.2). Phenolic compounds of the fresh garlic (12.61mg/g) were more than the three-month dated Allium sativum (2.89mg/g). The amount of allicin was respectively 15 µg/ml and 8 µg/ml in the fresh and three-month dated Allium sativum (p<0.05). The fresh garlic contains more useful substances and it is recommended to be used in its fresh estate.