Phenolic Compounds and Antioxidant Activity of Dried Peel of Iranian Pomegranate

Background: Literature review shows that there are not sufficient data about polyphenolic compounds of peel of Iranian pomegranate. So, this work was mainly undertaken to determine phenolic compounds and antioxidant activity of dried peel of Iranian pomegranate. Methods: Pomegranate fruits were obtained from mature fruits grown in Saveh, Iran and the Pomegranate Peel (PP) were dried with three different methods. Powders of PP were extracted with four different solvents, using a soxhlet apparatus. The compounds of PP extracts were analyzed by High Performance Liquid Chromatography (HPLC). Then, yield percentage and Radical Scavenging Activity (RSA) were determined. Statistical analysis was performed using the SAS 9.1 software. Results: Different ranges of tannic acids, testosterone and α-estradiol, estriol, estrone, cyanidin 3-glucoside, cyanidin3,5-diglucoside, pelargonidin 3-glucoside, pelargonidin 3,5diglucoside, and delphinidin 3-glucoside were identified. Both the highest yield percentage (18.820±0.661) as well as the highest RSA percentage (63.862±0.376) were obtained from the ethanol showing significant (p<0.05) difference with the other solvents. Drying method of PP showed no significant (p>0.05) relationship with yield of extraction and also antioxidant activity of the PP extracts. Conclusion: HPLC analysis identified some various phenolic compounds in Iranian PP extract showing considerable antioxidant activities. Although drying method showed no relation with yield of extraction and also antioxidant activity of the PP extracts, but type of solvent was effective on yield of extraction and type of extracted compounds of PP.