Tannin Removal by Hot Water as the Pretreatment of the Multi Stages Extraction of Phaleria macrocarpa Bioactive Compounds

Abstract

Phaleria macrocarpa is a native Indonesia plant originated from Papua. Its fruit, which is known and widely used as herbal medicine contains various bioactive compounds such as poliphenol, flavonoids, tannin, alkaloid, saponin, sterol, and terpenoid. They contribute to the antioxidant and antimicrobial activities of the fruit extract. The objective of this study was to assess the selection of solvent treatments which were not only capable of removing unwanted tannin and other sticky components, but also maintained the high content of the antioxidants. A pretreatment prior to the extraction was carried out by using hot water with temperature range of 55 – 100°C to remove tannin. The best pretreatment temperature was then used with a combination of non-polar (n-hexane and chloroform), semi-polar (ethyl acetate), and polar (70% ethanol) solvents. The results showed that the best operating pretreatment temperature for the removal of tannin was 65°C, with removal of 0.5798 mg gallic acid equivalents / g feed. Meanwhile, the best solvent combination was a two stages extraction with ethyl acetate and ethanol which could reduce the tannin content as much as 13%. Finally, ethanol extracts obtained from this combination resulted in the yield of 0.0696 g crude extract / g feed, tannin content of 2.9830 mg gallic acid equivalents / g crude extract, and antioxidant activity of 2.1983 μmoles DPPH / mg crude extract.