Eco‐Friendly Surfactants From <scp> <i>Pithecellobium dulce</i> </scp> : Extraction, Characterization and Surface Activity

ABSTRACT The widespread use of synthetic surfactants in industrial and domestic applications has raised environmental concerns due to their biodegradability and ecological issues. The purpose of this study was to explore Pithecellobium dulce (Roxb.) Benth. as a sustainable source of natural surfactants to address this limitations of synthetic surfactants. To achieve this, saponins were extracted from the leaf, fruit, bark, and stem of P. dulce using a hot ethanolic extraction followed by n‐butanol partitioning. The extracts were characterized by FTIR to confirm the presence of functional groups typical of saponins. Their surface‐active properties were evaluated through surface‐tension measurements using the Wilhelmy plate method to determine the critical micelle concentration (CMC), as well as foaming capacity and foam stability tests. The results revealed that saponins from all plant parts exhibited effective surface activity, with fruit extracts showing the greatest efficiency in reducing surface tension to ~32 mN m −1 , followed by stem, leaf, and bark extracts. Among all samples, the bark extract yielded the highest saponin content (6.4%), whereas the fruit extract showed the strongest surface activity. These findings highlight P. dulce as a promising natural source of surfactants, offering an environmentally friendly alternative for use in detergents, cosmetics and other industrial formulations.