Surface-active Properties of Extracted Saponin from the Leaves of Nephelium Lappaceum.

Synthetic surfactants are widely used in a wide array of cleaning products due to their ability in lowering the surface tension of water. These surfactants also come with bad effects on people's health and the environment. Plant-based surfactant, or saponin, is expected to produce the same desired effect of chemical surfactant, minus the negative effect. The purpose of the current research was to discover the surface-active properties of saponin extracted from  Nephelium Lappaceum or rambutan leaves, relative to commercial surfactant, Tween 80, and SDS. Rambutan’s leaves were extracted by maceration technique and liquid-liquid extraction to remove proteins and lipids of the plant. The presence of saponin in crude rambutan leaves was verified by foam test, which showed positive results. The crude rambutan leaves extracts were further analyzed by FTIR, GC-MS, and LC-QTOF-MS. The surface-active test consisted of a wetting test and cleaning test. The results from the IR spectrum show the presence of functional groups of saponin; OH, C=O, C-H, C=C, then, C-O which indicates the glycosides linkages to sapogenins. The wetting time for leave extracts, SDS, and Tween 80 were 32.33s, 7.33s, and 17.62s respectively. The cleaning test of saponin fraction, SDS, and Tween 80 showed the percentage of 20.98, 80.40, and 37.3 respectively. Generally, Rambutan leaves extract showed promising, but lower surface activities compared to commercial surfactants. Considering that the saponin fraction was not yet in the purest or isolated form of a single compound, it can be said the potential can be further enhanced by further isolating a pure surface-active compound from the saponin fraction.