Aug. 20, 2009 (United Press International) -- The Campbell Soup Co. (NYSE:CPB) , based in Camden, N.J., has cut sodium by almost one-third in its tomato soup, but says the flavor is the same customers grew up with.

The company began shipping the reduced-sodium soup to stores in July. Campbell, in its announcement, said the soup has the same flavor its customers grew up with, crediting a proprietary combination of sea salts and changes in other flavorings. Taste tests were conducted in all 50 states.

Campbell began producing tomato soup in 1897. Immortalized by artist Andy Warhol, the familiar can is one of the country's best-known food products and one of Campbell's top sellers.

The company has not branded the soup as low-sodium, presumably due to concern that some consumers equate low-sodium with bland taste.

"We hope it's the biggest change you never notice," Denise Morrison, president of Campbell Soup North America, told The Sacramento Bee during a visit to the company's research facility in Davis, Calif.

The new recipe meets federal guidelines for products labeled "healthy," which require 480 mg of sodium or less in a serving.

(An earlier version of this story contained incorrect information.)