Plant of Muntingia calabura L are often known as “kersen”, "seri or "cherry". Leaves of Muntingia calabura L. contains many benefits but its properties are still little known to the public. It contains secondary metabolites which have many uses. This study was aimed to determine the content of secondary metabolites in this leaf. Leaves extracts were obtained by maceration extraction for 3 times 24 hours using polar, semi-polar and non-polar solvents to determine the solubility of secondary metabolite compounds in each solvent. The solvents used were ethanol, ethyl acetate and n-hexane. The leaveswere dissolved a lot in polar solvents, marked by the formation of a dark green color in ethanol-series extracts, the color fades more in semi-polar and non-polar solvents. The three leaves extracts were tested for secondary metabolite contents by phytochemical screening tests. Phytochemical screening was an initial selection stage to detect classes of chemical compounds contained in plant. Phytochemical screening were included alkaloid, terpenoid, steroid, tannin, flavonoidand saponin tests. Based on the results of phytochemical screening tests, the leaf was contained several secondary metabolite compounds, namely flavonoids, saponins, steroids, terpenoids, alkaloids, phenols and tannins.

Many foods from Indonesia are cooked through the frying process using cooking oil. Good cooking oil is oil that has a low amount of peroxide and acid. The purpose of this study was to find the effect of adding dragon fruit juice (Hylocereus undatus)to peroxide numbers and acid numbers in used cooking oil. Peroxide numbers were measured using the iodometry method, whereas acidic numbers were carried out by the acid-base method. The results of this study indicated that after the addition of dragon fruit juice the peroxide number was dropped to 2.4 meg / kg, whereas in acid numbers an acid number was increased to 6.08 percent.