Only 48 percent of the cooked meat at nine supermarkets and stores in Guangzhou, Guangdong province, passed a quality test earlier this year, the city's administration of industry and commerce reported on Tuesday.
The 50 samples in the test, including roast duck, goose, pork and ribs, came from 12 producers.
None of the 10 samples at the two stores in Yuexiu district passed the test.
Supermarkets fared better than the stores in the test.
All three producers from outside Guangzhou passed the test, with 44 percent of those from Guangzhou failing, which can be attributed to the fact that the Guangzhou-made products were mostly unpacked with a shorter shelf life.
The 26 samples failing the test, all unpacked, were found to contain excessive bacteria and artificial coloring agents, the administration said.
For example, samples of roast chicken drumsticks and black pepper roast chicken sold at a Trust-Mart supermarket in Baiyun district, produced in January, were found to have excessive bacteria. Five products, including roast pork, roast duck and salted chicken produced by Guangzhou Zuijia Food Co in Baiyun district, were found to have excessive coliform bacteria.
The excessive bacteria may have resulted from dirty production equipment, poor material quality, production environment and staff hygiene, and inadequate storage.
Seven samples, including chicken and chicken feet products sold at Zhongxing shopping mall in Panyu district, contained excessive tartrazine, and one sample contained sunset yellow. The artificial coloring agents, which cost less than the natural ones, were used to enhance the look of the products.
The administration has pulled the substandard foods from the shelves. It has advised consumers to buy cooked meat only from qualified producers, scrutinize the color of the foods and heat the cooked meat products before eating them.
The problem arises from a lack of regulation in the production and storage process, said Li Biansheng, secretary-general of Guangdong Institute of Food Science and Technology.
Cooked meat, when left unfrozen for some time, breeds bacteria. Some producers may not have standards in place regarding artificial coloring agents, he said, urging stricter supervision.
In terms of bacteria, frozen or freshly cooked meat is much safer, he said.
Wang Chong, a retiree in Guangzhou, said she seldom buys cooked meat, always being suspicious of its quality.
The government should thoroughly investigate such cases when they are exposed and severely punish those responsible, she said.
Meanwhile, many roast geese sold in cities like Guangzhou and Shenzhen, where they are a local delicacy, are actually ducks, which cost less, Guangzhou Daily reported on Monday.
Some roast ducks are stuffed with meat on top of their heads to make them look like geese.
A visit to 10 cooked meat stores at a few wet markets in Guangzhou uncovered that half were selling roast ducks as roast geese.