Evaluation of different extraction methods on antioxidant compounds of dog-rose mountain, red hawthorn and black hawthorn (Mazandaran fruits)

Free radicals are considered harmful and damaging compounds to plant and animal cells and damage human health. Phenols are a large group of hydroxyl compounds that include compounds such as flavonoids and anthocyanins. Mountain dog-rose, red hawthorn and black hawthorn are three medicinal fruits with valuable compounds such as polyphenols, flavonoids, and vitamins, in the north of the country, with very favorable vegetative and reproductive growth. 

In order to investigate and determine the maximum amount of extraction of antioxidant compounds, different extraction methods were used in these fruits. The fruits of these plants were collected from Nava area (52.209 and 35.854, altitude 2300 meters above sea level) located in Amol City. After drying, they were extracted with four solvents i.e. water, ethanol, hydroalcohol (water and ethanol 50:50) and methanol. Then the amount of phenol, flavonoid and percentage of DPPH free radicals were measured for each fruit and extraction method. 

The results of this research showed that different extraction methods of dog-rose fruit have a significant difference at the level of 1% (p<0.01) on phenol and antioxidants and at the level of 5% (p<0.05) on flavonoids. Also, based on the comparison of the average extraction methods in the dog-rose fruit, the use of hydroalcoholic solvent (water and ethanol) caused a significant difference compared to other solvents and was able to show the highest amount of total phenol in this plant. The effects of different extraction methods on the fruit of the red hawthorn showed all extraction methods (water, hydroalcoholic, ethanolic and methanolic) were effective on the amount of phenol, flavonoid and antioxidant and were significant at 1% level. Based on the comparison of the average extraction methods in the red hawthorn fruit, the extracts obtained from the hydroalcohol solvent showed the highest number in phenolic and flavonoid traits and were the superior treatment. Extraction methods were significant in flavonoid and antioxidant traits at the level of 1% (p<0.01) and in phenol at the level of 5% (p<0.05) in the black hawthorn fruit. Also, based on the results of the comparison table of the average extraction methods in the fruit of black hawthorn, hydroalcohol solvent was the best solvent in extracting phenolic compounds compared to other solvents.

The phenolic compounds of the three medicinal fruits were more favorable by hydroalcohol solvent than other solvents, such as water, ethanol and methanol. Also, the highest amount of phenol among the three tested fruits was observed in the dog-rose mountain fruit. While in the red hawthorn, hydroalcohol (water and ethanol) and in the black hawthorn, methanol contained the most measured flavonoids. In general and considering the importance of phenolic compounds, it is suggested to use hydroalcohol solvent to extract these types of compounds in these plants.