Cilantro’s punch

The cilantro used in making salsa and other spicy dishes contains a potent compound that kills the bacteria most commonly responsible for food poisoning, researchers have found.

Although there is probably not enough of the compound in most foods to prevent an infection, U.S. and Mexican researchers say the tasteless antibiotic could eventually become a protective food additive. Previous studies have shown that salsa has antibacterial activity against a variety of germs. In fact, many researchers believe that humans developed a taste for spicy seasonings because of their antibacterial properties.

Chemist Isao Kubo of UC Berkeley and his colleagues at Berkeley and the Autonomous University of Guadalajara studied the components of cilantro and found that one chemical, dodecanol, had the most potent activity against several salmonella species.

Kubo said it was the only naturally occurring compound that is more effective against salmonella than the commonly used antibiotic gentamicin. But it is present in cilantro at only very low levels.

“If you were eating a hot dog or hamburger,” Kubo said, “you would probably have to eat an equivalent weight of cilantro” to protect against food poisoning. But salsa contains at least a dozen other less potent antibacterial compounds, he added, and their cumulative effect may be beneficial.

Dodecanol shows promise as a food additive because its mechanism of action is different than that of prescription antibiotics and it could be added in substantially higher quantities than are present in cilantro. Rather than interfering with metabolic activity, it disrupts the bacteria’s cellular membrane. It is thus unlikely that bacteria would develop resistance to it, he said.

The findings were reported in the current issue of the Journal of Agricultural and Food Chemistry.