Background: Bekulfruit from Northern region (Buleleng regency), Bali, Indonesia, is commonly consumed fresh in the island of Bali or processed as local delicacy and used as part of religious offerings. Up to date, there is no data regarding the taxonomy, phytochemical composition, and antioxidant properties of this Balinese fruit.This study was aimed to investigate total phenolic content, tannin content and antioxidant activity of the ethanol extract of bekul fruit obtained from Banjar district, Buleleng regency, Bali.

Methods: Total phenolic compound was quantified in terms of gallic acid equivalent (GAE) by using Folin-Ciocalteu method, mean while tannin content was determined in terms of tannic acid equivalent (TAE). IC₅₀of the extract was determined using DPPH assay, and subsequently used in the calculation of antioxidant activity index (AAI) using the formula of Scherer and Godoy (2009).

Results: Bekul plant was revealed as Ziziphusjujuba Mill. Total phenolic and tannin content of the extract was 29.48 mg/100 g GAE and 91.06 mg/100 g TAE, respectively. Thevalue of IC50was 77.40 mg/ml, with antioxidant activity index (AAI) of 50.94.

Conclusion:Ethanol extract of bekul (Ziziphusjujuba Mill.) fruit contains phenolic and tannin compounds. This extract is found to scavenge free radicals and possess very strong antioxidant activityin vitro. Taken together, these findings lead to the notion that bekul fruit from Northern region of Bali, Indonesia, is a promising pharma food.