Pulsed light reduces allergens in peanuts

U. FLORIDA (US) — Pulsed UV light can reduce the allergenic potential of peanuts by up to 90 percent, a discovery that may help make food safer for people with nut allergies.

The concentrated bursts of light, known as PUV, change peanut allergens so that human antibodies can’t recognize them. This prevents the release of histamines, which can lead to serious and sometimes deadly allergic reactions.

“We believe the allergen can be controlled at the processing stage, before the product even goes to the shelf,” says food scientist Wade Yang, an assistant professor at the University of Florida.


More than 3 million Americans are allergic to peanuts and tree nuts. Peanuts have been found to cause the majority of deaths in the U.S. from anaphylaxis, or severe allergic reaction. Such reactions can occur from eating peanuts or from even the slightest exposure in some individuals. Currently, the best way for those with the allergy to be safe is to completely avoid peanuts.

Using PUV, Yang reduced the allergenic potential of three of the most allergenic proteins in peanuts. The reduction of one of the proteins—Ara h2, the most potent of the three—marked the first time this reduction has ever been achieved with PUV.

Yang confirmed the allergy reduction using a biochemical test and by exposing the proteins to serum samples from patients with peanut allergies to see if an allergic reaction occurred.

Allergens were reduced in peanut extracts and peanut butter. Preliminary, unpublished results also demonstrate that PUV can significantly reduce the allergenic potential of whole peanuts.

Shih-Wen Huang, a pediatric allergist at the University of Florida, says epidemiological data show an increase in food allergies over the last 20 years.

Scientists don’t know why, he notes, but there could be multiple factors involved, including living in a cleaner environment that shifts our immune response away from protecting against germs to reacting to innocent food substances.

He also notes that increased peanut consumption is part of an overall trend toward healthier eating.

Huang says epinephrine is often recommended for treating severe allergic reactions, and for milder reactions, antihistamines.

And while epinephrine and antihistamines alleviate allergenic symptoms, Yang says he would like to prevent the allergy at the processing stage with PUV, before it reaches humans.

Yang’s future research involves developing a one-step roasting and allergen reduction process by PUV to produce hypoallergenic whole peanuts.

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