Fundamental exploration of Sophorolipids and Rhamnolipids technologies and its potential use in household formulations

Microbial biosurfactants are materials of great interest in personal care and household applications due to its eco-friendly nature, good biodegradability, surface activity, mildness on skin and emulsification capacity. These properties may translate into benefits against traditional surfactants (synthetic or natural derived). As the biosurfactant's cost seems like a challenge for its implementation in mass market consumer goods, they need to be investigated to assess their cost- benefits relation. 
This investigation focuses on the fundamental characterization (interfacial and surface tension in solution, foaming, wetting over beef tallow, and its emulsification capacity) of two types of commercially available biosurfactants: sophorolipids (SL) and rhamnolipids (RL), exploring different compositions from different suppliers. Biosurfactants were tested as single materials and blends to assess its potential as main or co-surfactant in a household product like surface cleaners and Dishwashing Liquids (DWL). The selected experimental techniques provide an insight of its emulsification (fragrance or soils), degreasing, and cleaning performance. Biosurfactants also were added to a model anionic:amphoteric surfactant base to evaluate their impact on aesthetics and viscosity.
It was observed that Rhamnolipids provide a superior performance than Sophorolipids in interfacial/surface tension reduction, wetting, foam amount, and foam lasting in the presence of grease soils. Emulsification also was favored by the Rhamnolipids as they bring a higher amount of grease soil in the liquid.  Rhamnolipids may be used in either DWL or surface cleaners products, where a high wetting and grease removal is expected. High lactonic sophorolipids have potential application in DWL and hard surface cleaners contributing to wetting and also thickening. High acidic sophorolipids showed the lowest performance among the materials tested, although not significantly different in multiple attributes, however its wetting capacity indicated that it could serve as partial replacement of anionic surfactants like dodecylbenzene sulfonate to improve performance in cleaner products.