Research published earlier this year by the Royal Society of Chemistry assessed the effects of different variables on the capacity of hair to adsorb a corn steep liquor-derived biosurfactant. The independent variables were temperature (20–50°C), pH (5–7) and treatment time (2–30 min); the dependent variable was the adsorption capacity of hair.
The adsorption of biosurfactant was fast, occurring just minutes after starting the experiments. Of the variables studied, time was the least significant whereas temperature had an important effect—the capacity of hair to adsorb the biosurfactant was improved at low temperatures.
pH had an intermediate effect, mainly at mid to high temperatures, while at low temperatures, the pH almost did not affect the adsorption process. At a higher concentration of biosurfactant, hair could adsorb with a maximum capacity of 3679 μg/g.