When the long-time McDonald's meat supplier - Shanghai Husi Food Co was shut down, this famous fast-food brand was again brought under the spotlight by food safety scandals.

The impact at McDonald's menu was far greater. A spokeswoman, Heidi Barker Sa Shekhem, said the Shanghai plant supplied products including sausage patties, ham patties, beef patties and chicken nuggets. As of July 23, McDonald's locations in Shanghai were still unable to serve some items.

Scandals on McDonald's in 2013 also showed that this chain has been using quick-growth chicken.

Due to the vast size of the fast-food market in China, which poses an obstacle to consistent regulating, foreign companies are going to need to invest a lot more resources in their supply lines, an expert said.

A giant logo of fast-food restaurant McDonald's is displayed at a train station in Shenyang, Northeast China's Liaoning province, May 21, 2011. [Photo/IC]