China said Friday that inspectors in the ports of Ningbo and Shenzen found bacteria and sulfur dioxide in products shipped by three American companies.

"The products failed to meet the sanitary standards of China," the General Administration of Quality Supervision, Inspection and Quarantine said in a notice posted on its Web site.

The companies were identified as K-Max Health Products Co., CMO Distribution Center of America, Inc., and Supervalu International Division.

On Saturday, state television showed inspectors in the southern province of Guangdong rejecting a two-ton shipment of pistachios because they contained what the report called "milky white ants," which looked similar to termites.

China Central Television said the ants could "cause a serious threat to trees and to the ecological environment." Part of the batch will be destroyed and the rest will be returned, the report said.

Footage showed safety certificates from the US issued to Cal-Pure Pistachios Inc., based in Bakersfield, California.

The state quality agency said K-Max and CMO exported health capsules, including bee pollen and bacteria-fighting supplements. Supervalu exported Sun-Maid Golden Raisins, it said. The shipments from K-Max and Supervalu have been destroyed and CMO's capsules were returned, the notice said.

The US FDA's assistant commissioner for food protection, Dr. David Acheson, said US officials were seeking more information.

Supervalu spokeswoman Rebekah Fawcett said its international division "works closely with our vendors and our manufacturers to ensure that the products we import and export adhere to quality standards and safety specifications." Supervalu International is part of Supervalu Inc., headquartered in Eden Prairie, Minnesota.

"Local quality officials should step up the inspection and quarantine on imported food products from the US," the Chinese notice said. "Chinese importers should also clarify food safety demands in contracts when importing US food products, so as to lower the trade risk." 

Friday's announcement was the second mention in recent days of China rejecting foreign food imports. Late last month, France's Groupe Danone SA said China seized five containers of Evian water in February because of concern over high bacteria levels.

K-Max president Liei Ye did not immediately respond to a message left with the company Friday seeking comment. K-Max is a subsidiary of Kang Long Group Corp., whose Web site said the company began by selling Wisconsin-grown ginseng to US health food stores under its K-Max brand, before expanding into China, Russia, Japan, Korea and other markets. Kang Long has four mainland China offices and a Hong Kong branch in addition to its Pomona, Calif., headquarters, according to the site.

The FDA said in 2000 that CMO Distribution Center of America was based in Sarasota, Florida. However, state records showed it was dissolved as a company in Florida in 2003.