Grape-seed extract, a byproduct of wine and grape juice production, is a popular dietary supplement taken by many Europeans for high cholesterol and hypertension. Research published in Applied and Environmental Microbiology suggests grape-seed extract also has natural disinfectant properties that may help to prevent outbreaks of severe gastroenteritis from highly infectious noroviruses, the cause of 60% of food-related illnesses in the U.S.
U.S. and Belgian scientists tested grape-seed extract on cultured cells, vegetable rinse water, and food-preparation surfaces infected with a surrogate mouse strain of norovirus.
Grape-seed extract contained 13% catechin and 19% epicatechin, nontoxic plant-based compounds known as flavonoids, which have been shown to have many antioxidant and antimicrobial effects on human health.
Grape-seed extract treatment neutralized the virus's infectious properties to undetectable levels in cell cultures, though a higher dose was needed when a small amount of dried milk was added to the culture, indicating proteins may interfere with grape-seed extract, researchers said.
The extract also reduced the virus's potency in norovirus-contaminated water used to wash lettuce, but had no significant effect on contaminated stainless-steel surfaces. After treatment, norovirus particles clumped together and appeared deformed; the virus's outer protein shell was also damaged.
The findings may be important to the food industry as fresh produce is often implicated in norovirus outbreaks, researchers said.
Caveat: As human noroviruses aren't easily cultured, the experiments used a surrogate strain of the virus that shares the biological features of human norovirus.
—Ann LukitsA version of this article appeared October 23, 2012, on page D2 in the U.S. edition of The Wall Street Journal, with the headline: Possible Fighters of Food-Borne Ills: Grape Seeds.
