Spanish settlers introduced pomegranates to California in the 18th century, but L.A. billionaires Stewart and Lynda Resnick consider themselves 21st century gatekeepers of the ruby red fruit.

The Resnicks own pomegranate juice manufacturer POM Wonderful LLC, which, as the largest grower of pomegranates in the United States, has become a little empire that distributes pomegranate juice, pomegranate tea, pomegranate pills and, yes, even fresh pomegranates.

The Resnicks have been known to put on the gloves to fight for their pomegranate domain. But lately, they’ve gone up a couple of classes and have stepped into the ring with heavyweights, picking fights with big companies that make pomegranate juice.

POM filed three federal lawsuits in January against Welch’s, Tropicana Products Inc. and Ocean Spray Cranberries Inc. In September, beverage giant Coca-Cola Co., which distributes Minute Maid, and Texas-based food supplier Fresherized Foods Inc. got the POM treatment when the company hit them with federal lawsuits as well.

POM claims in all five suits that its competitors are falsely advertising their products as primarily containing pomegranate juice, however, POM alleges the competitors’ products are blended with other fruit juices. POM argues that the companies are confusing consumers into thinking that their products provide the same health benefits as POM’s 100 percent pure pomegranate beverage.

By targeting such prominent companies, the Resnicks have raised their sights from previous years when they successfully took on a smaller juice competitor.

Beverage consultants aren’t surprised by POM’s aggressive tactics. Industry experts said that oftentimes larger companies will copy smaller competitors that have successfully introduced a product.

“Once the little guy proves it’s going to work, there is the big guy ready to take advantage,” said Celeste Viale, a consultant with Florida-based Beverage Consulting Services Inc.

Spokespeople for POM, Tropicana and Coca-Cola did not respond to the Business Journal’s requests for comment. Fresherized Foods and Welch’s declined to comment on the pending litigation.

John Isaf, an Ocean Spray spokesman, said the company will continue to label its products as it currently does, and will defend its position in court.

“As far as the litigation, the only thing we have to say is that all of our labeling complies with the requirements of the national juice labeling act,” Isaf said.

POM is part of the Resnicks’ private holding company, West L.A.-based Roll International Corp., which also owns bottled water company Fiji Water, online flower delivery service Teleflora, almond and pistachio producer Paramount Farming Co. and fresh citrus harvester Paramount Citrus.