Shanghai's food and drug authorities said on Wednesday that the city had established a fast testing system for food safety.

"The system can tell the safety of most food products within 30 minutes," said Li Jie, deputy director of the Shanghai Food and Drug Supervision Institute.

All the districts and counties in the city have been equipped with food safety testing vehicles and personnel, said Li.

Food safety has become one of the major concerns of Chinese citizens as a number of food contamination accidents have been exposed across the country in recent months.

Last November, the country's food safety watchdog found that seven companies that were producing salted red-yolk eggs contaminated with dangerous red Sudan dyes, which are used legally in the leather and fabric industries, but are banned for food use.

Also last year, carcinogenic residue was detected in turbot sold on markets in Beijing and Shanghai.

China's quality control watchdog announced on Tuesday two Chinese companies exported melamine-contaminated wheat gluten and rice protein.

An official from the Legislative Affairs Office of the State Council said his department would finish drafting the amendments to the Food Safety Law soon.