China rejects another U.S. food shipment.

China's quarantine bureau has destroyed a cargo of 21.6 tonnes of frozen potato slices shipped from the United States, saying it was of sub-standard quality, the International Business Daily reported last week. China is increasingly publicizing instances in which it detects quality problems with imports from the U.S., in apparent response to U.S. complaints about sub-standard Chinese exports of food, fish, tyres and toys. The potato cargo was checked recently and did not meet quality specifications including acidity levels, the paper said, without saying when it arrived in Chinese ports.

Earlier this month, the quarantine bureau warned the U.S. about exporting contaminated soybeans, singling out a substandard cargo that had arrived in February. The bureau said in June it would apply greater scrutiny to shipments of food from the U.S., and later blocked shipments of poultry and meat from some of the largest U.S. suppliers.