Screening of phenolic content and antioxidant capacity of Okitsu mandarin (Citrus unshui Marc.) juice extracted with various solvents

Abstract

This study aims to compare the effect of using various solvents to obtain phenolic extract from ‘Satsuma Okitsu’ mandarin (Citrus unshui Marc.) juice and characterize their phenolic profiles and determine their antioxidant capacity. Three different solvents were used to extract phenolic content of mandarin juice as water, methanol and ethanol. A total of 17 phenolic compounds were identified and quantified in all samples by LC-DAD-ESI-MS/MS. According to results, among all phenolics, narirutin (naringenin-7-O-rutinoside) was the most abundant compound with the concentrations of 164.3, 201.2 and 203.7 mg/L for the aqueous, methanolic and ethanolic extracts respectively. In the aqueous extract, narirutin was followed by feruloyl-galactaric acid and luteolin-6,8-di-C-glucoside with 66.4 and 61.5 mg/L. However, hesperidin (hesperetin-7-O-rutinoside) was the second most abundant compound in methanolic and ethanolic extracts with the concentrations of 83.9 and 125.0 mg/L. In addition, beyond the phenolic content ranged from 532.1, 691.3 and 755.6 mg/L in the mandarin juice for the aqueous, methanolic and ethanolic extracts respectively. Beyond the phenolic profiles, the antioxidant capacity of three extracts was investigated using DPPH and ABTS assays. According to revealed results, the ethanolic extracts possessed the highest antioxidant activity and followed by methanolic extracts.