China defended its food safety standards on Thursday, guaranteeing the quality of its exports and shrugging off concerns of tit-for-tat trade disputes with the United States after seizing two shipments of U.S. fruit.

China has cracked down on domestic food producers after a series of food scandals at home and reports that mislabelled chemical exports were mixed into cough syrup in Panama and pet food in the United States, with deadly results.

Ministry of Commerce spokesman Wang Xinpei said China would also scrutinise imports and deal with violations according to international practices and safety standards.

"The Chinese government will take measures to deal with any imported food that does not meet those safety standards," Wang told a news conference.

Chinese quarantine officials said on Tuesday they had seized shipments of orange pulp and preserved apricots from the United States, citing high levels of bacteria, mildew and sulphur dioxide.

But Wang also insisted China was taking concerns about contaminated toothpaste seriously, and that Chinese food shipments to the rest of the world were safe.

"China pays close attention to anything that concerns food safety, especially people's health, no matter whether it's food imported from other countries or exported from China," he said.

"The quality of food imported from China is guaranteed."

The health concerns have triggered a clean-up in China's food industry. Authorities shut down 180 domestic food manufacturers during the past six months for making substandard food or using unedible materials for food production, state media said this week.

Chinese legislators identified food safety as one of their top concerns during an annual meeting in March, after a spate of incidents involving fake, dangerous or mishandled products killed or sickened dozens of Chinese.

Product safety disputes with the United States have spread beyond food.

A New Jersey importer this week asked for U.S. government help in recalling about 450,000 Chinese-made truck tyres. The Hangzhou Zhongce Rubber Co. has disputed the assertion that its products were defective.