The Extraction and Activity Test of Bioactive Compounds in Phaleria Macrocarpa as Antioxidants

Phaleria macrocarpa, one of native Indonesian plants, contains various bioactive compounds and thus possesses antioxidant, antimicrobial, or even anti cancer attributes. This study is the first stage of ongoing 3 years project to isolate and quantify the antioxidant content in the fruit of Phaleria macrocarpa, which possessed higher antioxidant activity than berry fruits, especially for natural food preservative application. In particular, the optimum condition for the extraction process using methanol was the main purpose of this study. The raw material pretreatment (drying) method prior to extraction was also investigated. The bioactivity of the extract obtained from each method was then compared to commercial dried P. macrocarpa by phytochemical screening methods. Tray and air drying methods resulted in the most complete phytochemical content followed by sun drying, in which the alkaloid were lost. Commercial dried P.macrocarpa showed similar phytochemical contents with sun drying specimen, but with additional lost of saponin compounds. The antioxidant contents were measured as DPPH equivalencies which showed tray drying method had the best antioxidant activity of 0.200 μmol DPPH/mg (dry basis), followed by air drying and sun drying of 0.117 and 0.037 μmol DPPH/mg (dry basis), respectively. Two important extraction process parameters were optimized using central composite experimental design by varying operation temperatures from 35 to 50 °C and F:S (g/mL) ratio from 1:20 to 1:50. The response surface analysis showed a maximum response point (F:S=0.02 and T= 50 °C), at which the highest antioxidant content (yield) of 0.3234 μmol DPPH/mg dry basis could be achieved.