It was only fitting that the town nicknamed "Sacra-tomato" should play host to 500 industry leaders for the World Congress on the Processing Tomato.

Sacramento has been a hub of tomato production since the 1940s, said Richard L. Orzalli, director of procurement for the Campbell Soup Co. and former president of the World Congress.

California grows more than 90 percent of tomatoes used for processing in the United States and nearly half the tomatoes processed worldwide, Orzalli said. Tomatoes grown for use in tomato-based products are firmer and stand up to mechanical harvesting better than other tomatoes.

The state produces so many tomatoes that more than a million will roll off trucks, smacking roadways and unlucky motorists, in this year's harvests alone, he said. The next harvest starts in July.

"With the deep soil, plentiful water and climate, we have the perfect growing conditions for tomatoes," Orzalli said.

And members of the World Congress of the Processing Tomato hope to tempt more consumers into eating more tomatoes by touting their nutritional benefits.

Though the industry can't claim tomatoes can definitely prevent cancer, studies that point to increased tomato consumption as a potential way to reduce cancer rates was a prominent topic at the four-day event that closed Tuesday.

"There is a strict regulatory framework in which you must provide clear and convincing scientific evidence before you can make those claims," said Jeff Boese, president of the California League of Food Processors. "The weight of our evidence on tomato products and cancer doesn't yet meet that standard."

Dr. David Heber, director of the Center for Human Nutrition at UCLA, said his research found that men who consumed 6 ounces a day of tomato and vegetable juice had a 40 percent lower rate of prostate gland cancer.

Tomatoes contain lycopene, an antioxidant, and processed tomatoes contain loads of lycopene, Heber said. Antioxidants search the body for roaming oxygen molecules known as free radicals suspected of triggering cancer.

"Tomatoes make lycopene to protect themselves from the sun. The more you grow them in hot weather, the more lycopene they produce and the redder they get," Heber said.

And the more tomatoes are boiled down, the more lycopene there is, he said.

"We recommend that consumers get five servings of tomatoes a week," Heber said. "You have different sauces, ketchup, tomato soup and juices. I advise people to use a variety of things so they don't get bored."

Some of Heber's patients take his advice by drinking a glass of tomato juice each day.

A 1995 Harvard study followed the eating habits of 47,000 men for six years and found that those who ate at least 10 weekly servings of tomato-based foods were up to 45 percent less likely to develop prostate cancer.

A recently released Harvard Medical School summary of 72 studies takes tomato power a step further, finding that lycopene seems to shrink prostate tumors.

The tomato has long been misunderstood. It was classified as a fruit until the U.S. Supreme Court intervened in 1898 and declared it a vegetable.