Antioxidant Content of Palm Fruit ( Borassus flabellifer L. ) Seed Coat

Background: Sunlight, cigarette smoke, and pollution substances triggered free radicals to get into the body. Antioxidant has functions to against free radicals. Borassus flabellifer ( B. flabellifer ) contains antioxidants however there is no study about the content of their wasted seed coat. Aim: This study aims to determine antioxidant content of B.flabellifer seed coat ethanol extract using DPPH ( 2,2-diphenyl-1-picrylhydrazyl ) assay. Methods: This in vitro experimental study was conducted by three main stages. First stage was B.flabellifer seed coat ethanol extract preparation. Second stage was the quantitative phytochemical tests. At the third stage, antioxidant activity was tested with DPPH assay using the DPPH powder as the free radical toward the seven groups which were negative control of the blank solution, ethanol extract of B.flabellifer seed coat concentration of 3 ppm, 6 ppm, 9 ppm, 12 ppm, 15 ppm, and positive control of gallic acid. Results: B.flabellifer seed coat ethanol extract contains antioxidant groups of flavonoid, phenol, and tannins. B.flabellifer seed coat ethanol extract and control positive of gallic acid has average IC 50 of 12,29 ppm and 0,96ppm respectively. coat ethanol extract and gallic acid showed a strong antioxidant characteristic. Conclusion: seed coat ethanol extracts contain antioxidant groups of flavonoid, phenol, and tannins and has a very strong antioxidant characteristic. However, have not surpassed the gallic acid as positive control.


Introduction
Antioxidants or anti-free radicals are molecules that are formed due to the presence of free radicals that give their electrons and combine with free electrons from other molecules or other nonradical molecules. The combination reaction between molecules and non-free radical molecules forms a chain reaction [1].
Antioxidant are divided into natural antioxidants and synthetic antioxidants [2]. According to the Public Health of Harvard School, antioxidants have thousands of groups such as flavonoids, phenol, polyphenols, glutathione, lipid acids, and others. The human body needs antioxidants to ward off free radicals that can be obtained from sun exposure, pollution, and cigarette smoke. Indonesia has quite a lot of fruit diversity. There are more than 329 types of fruit found either from Indonesia or immigrants from outside Indonesia. One of the fruits that grow in Indonesia is palm fruit (Borassus flabellifer L.). There are 2800 types of palm trees in the world, 460 species of palm trees grow in Indonesia. One of the 460 species of palm trees is the palm fruit tree [3]. Palm fruit grows in tropical areas such as NTT (East Nusa Tenggara), NTB (West Nusa Tenggara), South Sulawesi, Southeast Maluku, Madura, Bali, Central Java, and East Java (Figure 1) [4]. Palm fruit grows from trees that have a height of up to 30 meters and usually grows on sandy soil [5,6]. Meanwhile, every part of the palm fruit such as roots, stems, leaves, and treetops can be used.
Indonesian people usually only consume the fruit, and the seed coat is removed so that the seed coat in the palm fruit becomes trash. In previous studies, palm fruit contains natural antioxidants, especially xanthophylls and phenols groups [7,8]

Extract Preparation by Maceration Technique
Young B. flabellifer was washed under running water. Remove the seed coat and outer skin with a knife. Then, the seed coat of B.
flabellifer was dried at room temperature for 4-5 days, soaked in 70% ethanol solvent and stirred for 6 hours with a digital shaker.
Finally, the extract is filtered with filter paper and evaporated with a rotary vacuum evaporator until thick.

C. Tannins
The

D. Free Radicals Scavenging (DPPH Method)
The ethanol extract of B.flabellifer seed coat, methanol, and 160 ppm DPPH was combined into the test tube and incubated for 30 minutes after added the DPPH solution. The solution was measured at a wavelength of 517 nm with a UV-Vis spectrophotometer.

E. Data Analysis
Data analysis was performed by calculating the percentage of inhibition with the formula:

Results
Total of Flavonoids, Phenols, and Tannins was shown on Table   1.

Free Radicals Scavenging 1ith DPPH Method
The DPPH test was carried out at several concentrations of the ethanol extract of B.flabellifer seed coat, namely 3 ppm, 6 ppm, 9 ppm, 12 ppm, 15 ppm, and gallic acid as positive control. The test was carried out three times (  it is easy to do, effective, and a good way to study plant extracts [11]. Finally, the absorbance value is largely determined by the wavelength used when measuring the absorbance of a certain concentration with a UV-Vis spectrophotometer that was used in this study. This study used wavelength of 517 nm.