Dye solubilization ability of plant derived surfactant from Sapindus rarak DC. extracted with the assistance of ultrasonic waves

The study focused on the extraction and characterization of the natural surfactant, saponin, from lerak (Sapindus rarak DC.) and investigation of its ability to solubilize re-active dyes. Extraction by green ultrasound-assisted extraction showed that the highest saponin yield of 27.87 mg saponin/100 mg feed was achieved. The value was obtained at temperatures of 30 degrees C, with solvent to solute ratio of 10 mL/g, after 40 min of extraction. This yield was approximately twice that obtained from maceration-based extraction. Compared to maceration extraction (ME), UAE results showed improved extraction time, lower temperature, and lesser requirement for solvents. The study of the surfactant characteristics of saponin extracts also confirmed that the extracted saponin from lerak pericarp was an oleanane triterpenoid saponin. Both the extract and pure saponin were classified as hydrophilic saponin with HLB value of 16.8 and 18.7, respectively. Lerak pericarp extract has Critical Micelle Concentration of 0.19% wt. The solubilization of lerak pericarp extract to synthetic dyes expressed as molar solubilization power were 0.251 mM/mM and 0.239 mM/mM for Red Remazol dye and Blue TQ Remazol dye, respectively. (c) 2021 Elsevier B.V. All rights reserved.