LC-ESI-QTOF-MS/MS profiling of phenolic compounds in Australian native plums and their potential antioxidant activities

Abstract

Australian native plums are rich in phenolic compounds, which have significant health-promoting effects. There are limited recordings and information on the number of species and phenolic content of Australian native plums. However, the number of species and phenolic content of Australian native plums are not well documented. This research was conducted to identify and quantify phenolic compounds in the peel, pulp, and seed of three common Australian native plums (Kakadu plum, Davidson plum, Illawarra plum) for applying and promoting the commercial worth of these fruits. Total phenolic content (TPC), total flavonoid content (TFC), and total tannins content (TTC) were used to determine the amount of phenolic compounds in these Australian native plums and in vitro experiments, including total antioxidant capacity (TAC), 2, 2′-Diphenyl-2-picrylhydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP), and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were used to analyze the antioxidant activities of the samples. Phenolic compounds in the samples were thoroughly analyzed by liquid chromatography-mass spectrometry (LC-ESI-QTOF-MS/MS), and preliminarily identified as phenolic acids (10), flavonoids (23), and other phenolic substances (11). These results show the potent antioxidant properties of the Australian native plums and provide evidence for their potential use as culinary, medicinal, and nutraceutical components.