The government launched its campaign in April, following a wave of contamination scares and tainted-food scandals.
China has repeatedly pledged to clean up its vast food industry after milk products tainted with the industrial chemical melamine killed six babies and made 300,000 others ill in 2008.
The chemical was added to give the appearance of high protein content.
Although a new food safety law went into effect in 2009, China has been hit by numerous food scares since.
Authorities have discovered beansprouts laced with cancer-causing nitrates and steamed buns with banned chemical preservatives, as well as rice laced with heavy metals.
Experts say there are many causes for food safety problems in China, including unclear regulations and underfunded regulators.