The evaluation of antioxidant properties and stability of phenolic copmpounds from medlar (Mespilus germanica L.) fruit

Medlar is a widely growth in northern Iran and used as an edible fruit as well as in home remedies. In this study, the antioxidant properties and total phenolic contents of acetone, methanol, ethanol 80% and water extracts of medlar (Mespilus germanica L.) were examined. Maximum amount of phenolic compounds were obtained with acetone (80%), followed by methanol, ethanol and water. Total phenolic content of acetone extract was 7.437 g GAE/100gr dried matter. Antioxidant activity was evaluated using three different methods including scavenging effect on DPPH radicals, reducing power of Fe+3 and total antioxidant capacity. The results were compared with the antioxidant capacity of a synthetic antioxidant, BHT. Acetone extract displayed the highest antioxidant capacity in all the assays. In addition, the effect of temperature (50 °C and 100 °C), pH (3, 5, 7 and 9) on the antioxidant activity of acetone extract was investigated. The antioxidant activity of the extract remained unchanged at 50°C and was at maximum pH (5.0). Results showed that, medlar was found as a potential source of natural antioxidants due to its marked antioxidant activity.