U.S. scientists say waste cooking oil from restaurant deep fryers -- known as "yellow grease" -- could be transformed into therapeutic cosmetics.

Researchers from Dowling College in Oakdale, N.Y., say it is possible to transform waste cooking oil into inexpensive raw material for producing unusual biosurfactants with uses ranging from therapeutic cosmetics that regenerate damaged skin to controlling algae blooms in lakes and ponds.

Vishal Shah and colleagues estimate U.S. restaurants generate about 25 billion gallons of waste cooking oil each week. The waste oil -- marketed as "yellow grease" -- long has been used in animal feed, with researchers exploring new applications such as biodiesel fuel.

"We have successfully demonstrated the use of restaurant waste oil as a potential low-cost lipid feedstock for sophorolipid production," the researchers report.

Sophorolipids have a range of applications, including naturally derived ingredients in therapeutic cosmetics; germicidal solutions for washing fruits and vegetables; and anti-algal agents for environmental cleanups, the report notes.

The research is to be published in the journal Biotechnology Progress.

Copyright 2007 by United Press International