Evaluation of surfactant properties of saponins extracted from Entada phaseoloides

The widespread use of synthetic surfactants has raised environmental concerns due to their non-renewable source, poor biodegradability, and ecological toxicity, creating a demand for sustainable alternatives from renewable sources. This study investigated the surfactant properties of the crude saponin extracted from the seed kernels of Entada phaseoloides, a plant traditionally used as a natural detergent in many Asian countries. Saponin was extracted by Soxhlet extraction method with 70% ethanol, followed by n-butanol partitioning. The extract was characterized by solubility analysis and FTIR spectroscopy. In contrast, its solubility performance was evaluated through the measurements of electrical conductivity, surface tension, pH, foaming ability, foam stability, and cleaning ability. The extracted saponin exhibited characteristic amphiphilic behaviour. FTIR confirmed the presence of functional groups characteristic of saponin. The critical micelle concentration CMC determined by conductivity and surface tension measurements was 0.32–0.328 g/L with a surface tension reduction of water to 52.92 mN/m at CMC. The extract also exhibited spontaneous micellization, mildly acidic pH, good foaming ability, foam stability, and cleaning efficiency. These results demonstrate that crude saponins possess favourable physicochemical and surface- active properties, providing a scientific basis for their use as a cleansing agent and supporting their potential as renewable natural surfactants.