HONG KONG (REUTERS) - Several Chinese pharmaceutical companies have recalled their ginkgo biloba products due to quality issues with the extracts, in further evidence highlighting food safety issues in China.

Guizhou Yibai Pharmaceutical, Guizhou Xinbang Pharmaceutical and Sichuan Kelun Pharmaceutical said on Friday some of their ginkgo biloba products failed to meet national standards.

Ginkgo biloba tablets are popular in some parts of Asia, such as China, with companies often marketing them as dietary supplements that help improve memory.

"The company has recalled the products in the market and stopped production immediately with the in-house made extracts," Xinbang said in a statement posted on the Shenzhen stock exchange.

Xinbang said there were some quality problems with their own extracts and were working with relevant authorities to rectify the situation.

Friday's announcements came a week after Hunan Fangsheng Pharmaceutical made a similar move to remove its products from the shelves.