Soy and oat combo protects against UV. (Chemistry).

It might be winter, but two scientists in Peoria, Ill., have sunscreen on their minds. U.S. Department of Agriculture chemists have made a new, biodegradable sunscreen by using soybean oil and a natural chemical in oat bran.

Joe Laszlo and Dave Compton started working with the compound, called ferulic acid, because it's structurally similar to the synthetic chemicals in commercial sunscreens. Like the synthetics, ferulic acid absorbs skin-damaging ultraviolet light. But ferulic acid dissolves in water, making it unsuitable, by itself, for water-resistant sunscreens, says Compton. So he and Laszlo chemically bonded ferulic acid to soybean oil, yielding a waterproof formulation.

The process they developed uses no hazardous solvents and produces no waste, says Compton. The chemists dissolved ferulic acid compounds in soybean oil and used natural enzymes and heat to chemically link them. The enzymes were recovered and used again.

Initial tests indicate that the product, which the scientists call SoyScreen, absorbs UV light best at wavelengths from 320 to 360 nanometers. That's within the so-called UVA range, which is responsible for wrinkling and skin cancer. Two of three tested sunscreen chemicals absorbed light better than SoyScreen did in the sunburn-causing UVB range, but SoyScreen offered the best overall protection against both UVA and UVB, the researchers report.

The USDA patented the technology this year, and a fragrance-and-flavor company wants to license it, says Compton, who wouldn't identify the company. SoyScreen-containing cosmetics with antiwrinkling claims could be test-marketed as early as 2003 or 2004 and be on store shelves in 9.005, he says. However, Food and Drug Administration approval is necessary to make sun-protection-factor (SPF) claims for sunscreens, which could take many more years, he adds.--J.G.