Researchers at the Indian Institute of Technology, Madras, have discovered that the sap of Calotropis procera, a commonly found plant, makes for a natural emulsifier.

The latex sap from this plant (also known as ‘apple of Sodom’) is inexpensive, biodegradable, eco-friendly, and readily available, says an article in the IIT-Madras online journal ‘Tech Talk’.

Hemant Kumar and Madivala G Basavaraj from the Polymer Engineering and Colloid Science (PECS) Laboratory, Department of Chemical Engineering, say that the sap was tried with single, double, and multiple emulsions, and found to be an effective stabiliser. “This is because the latex has colloidal-scale particles which help in the inter-facial adsorption of solid particles,” the article says.

Emulsions are substances containing two or more immiscible (non-mixing) liquids. In order to stabilise such mixtures, substances known as emulsifiers are used. These include surfactants, polymers, colloidal particles, or a combination of these.

It was found that the latex sap from Calotropis procera is a versatile source for stabilisation of emulsions. The emulsions formed are found to exhibit excellent storage stability.

Prof Guruswamy Kumaraswamy of the Department of Chemical Engineering, IIT-Bombay, observed that “while more work is required to translate this into an industrial application, this work is an important first step in identifying naturally derived green alternatives for emulsifiers”.