Evaluation of Phenolic Contributors to Antioxidant Activity of 10 Berry Juices Using Cyclic Voltammetry Combined with Liquid Chromatography-Mass Spectrometry (LC-MS)

Abstract

In this study, an electrochemical method called cyclic voltammetry (CV), combined with spectrophotometry and liquid chromatography-mass spectrometry (LC-MS) were used to analyze and study the phenolic profiles of 10 freshly squeezed berry juices, including blackcurrant, blackberry, blueberry, boysenberry, cranberry, gooseberry, ranui berry, raspberry, red currant, and strawberry. The results showed that CV not only had a high correlation with spectrophotometric assays but also with compounds determined using LC-MS. The results support the use of CV as a rapid method in studying the phenolic profile and antioxidant strength of berry juices. Compared with other berry juices, blackcurrant, boysenberry and ranui berry showed higher total phenolic contents and better antioxidant capacity. Although phenolic compounds in berry juices varied between different cultivars, epicatechin played important role in all of the berry juices and considered as a predominant phenolic compound in blackberry, cranberry, ranui berry, raspberry, and red currant juice. Phenolic compounds were abundant in berry juices and directly contribute to their reducing powers. Moreover, a developed method was offered to analysis the typical phenolic compound in berry juice by CV and suggested a possible application in selecting better antioxidant capacity berry cultivars for producers.