Bioactive compounds, antioxidant properties and phenolic profile of pulp and seed of Syzygium cumini

Abstract

The present study was conducted to explore major bioactive compounds, antioxidant properties, along with individual phenolic compounds of Syzygium cumini fruit pulp (edible part, pulp with peel) and seed. The in vitro antioxidant properties of S. cumini fruit pulp and seed were analyzed using 2,2-diphenil-1-pycrilhydrazyl (DPPH), 2,2´-azino-bis (3-ethylbenzothiazolin)-6-sulfonic acid (ABTS) free radical scavenging assay methods. Phenolic profiles were explored using high performance liquid chromatography-diode array detector (HPLC–DAD). Total phenolics, flavonoids, and tannin content were significantly (P < 0.05) higher in seed extract and displayed better antioxidant properties than that of pulp extract. The antioxidant activities of S. cumini seed extract was comparable with other potent antioxidants like ascorbic acid. S. cumini seed extract demonstrated significantly higher antioxidant activity than ascorbic acid in ABTS free radical scavenging assay. Regression analysis showed a strong positive correlation between the concentration of bioactive compounds and free radical scavenging activity of the samples. Additionally, ten individual phenolic compounds among the nineteen standards were identified using HPLC–DAD analysis. Contents of gallic acid, epicatechin, and catechin hydrate were predominant among the identified phenolic compounds. This study showed that the seed of S. cumini has immense potential as a source of natural bioactive compounds with excellent antioxidant properties. The findings of the present study are pioneering to move to advanced research on the utilization of S. cumini seed as an alternative to artificial antioxidants in food products.