Phenolic Compounds and Antioxidant Activity of Juices from Ten Iranian Pomegranate Cultivars Depend on Extraction

Abstract

Phenolic compounds and antioxidant activities of ten juices from arils and whole pomegranate cultivars grown in Iran were studied. Phenolic contents and antioxidant activities of juices from whole pomegranate fruit were significantly higher than juices from pomegranate arils, but the variety has a greater influence than the processing method. The main phenolics in the studied juices were punicalagin A (5.40-285 mg/L), punicalagin B (25.9-884 mg/L), and ellagic acid (17.4-928 mg/L). The major and minor anthocyanins of cyanidin 3,5-diglucoside (0.7-94.7 mg/L), followed by cyanidin 3-glucoside (0.5-52.5 mg/L), pelargonidin 3,5-diglucoside + delphinidin 3-glucoside (0-10.3 mg/L), delphinidin 3,5-diglucoside (0-7.68 mg/L), pelargonidin 3-glucoside (0-9.40 mg/L), and cyanidin-pentoside (0-1.13 mg/L) were identified; the latter anthocyanin as well as cyanidin-pentoside-hexoside and delphinidin-pentoside were detected for the first time in Iranian pomegranates. The total phenolic contents were in the range of 220-2931 mg/100 mL. The results indicate that the pomegranate phenolics are not only influenced by extraction method but also - and even more - affected by the cultivar. Moreover, a good correlation was observed between total phenolic content and ABTS and FRAP methods in all pomegranate juices (>0.90). The results of current research can help to select the pomegranate cultivars for commercial juice production.