Plant-derived surfactants as an alternative to synthetic surfactants: surface and antioxidant activities

Biosurfactants have great advantages as an eco-friendly alternative to synthetic surfactants. Surface active properties and antioxidant activity of extracts prepared from Sapindus mukorossi, Verbascum densiflorum, Equisetum arvense, Betula pendula and Bellis perennis have been studied. The extract from Sapindus mukorossi served as a standard because it belongs to the most widely used natural surfactants. The surface active properties of these nonionic surfactants were also compared with the properties of common synthetic surfactants such as sodium lauryl sulfate (SLS) and Tween® 80. In many cases, the plant-derived surfactants showed better properties than the synthetic ones, e.g. minimum critical micelle concentration values were observed for E. arvense (0.033 g L^?1), B. perennis (0.076 g L^?1), or minimum surface tension reached for the extract of B. perennis (36.8 mN m^?1).