(Aug. 6) True Leaf Farms LLC, Salinas, Calif., will test its lettuce crops for pathogens before harvest — switching from a packinghouse test system — after a July recall of spring mix and arugula.

The company, which lost up to 53,000 cases of product, contends the positive salmonella test in late July was a result of cross-contamination at the third-party company that did the test, Silliker Inc., Modesto, Calif.

There were no illnesses reported.

True Leaf chief executive officer David Gill said the company is negotiating with Silliker to establish liability.

“They didn’t have any idea of the ramifications of a test-and-hold program and what it could do to all the other customers,” Gill said.

C.J. Reynolds, director of Silliker, based in Homewood, Ill., declined to comment, citing a company policy not to discuss details of test results.

“We also ship raw product to one other company that puts it in retail blends. So they had to recall their items, too,” Gill said, declining to name the company.

The Food and Drug Administration briefly posted a news release on its Web site from True Leaf about the recall, but it was taken down by July 27. The recall affected product packed July 19-25. The FDA did not list any other companies involved in the recall.

Reynolds said the Silliker is continuing to talk with True Leaf to better understand the effects of the recall but said negotiations have not begun yet and that True Leaf is still determining the dollar value of its losses.

“We understand the shortness of the shelf life and what that means,” she said. “There’s a lot of discussion of where is the best place in the food chain to be testing.”

She said if a company engages in a test-and-hold program it’s important to understand the time requirements.