BEIJING, Feb. 6- Chinese police apprehended nearly 30,000 in connection with food and drug safety offences in 2014, closing 35,000 illegal factories and workshops, the Ministry of Public Security revealed Friday.

Food safety is still a serious problem in China, despite of some improvement, the ministry's Hua Jingfeng told a press conference.

Hua noted that cases related to baby formula and "gutter oil" have decreased, but those concerning other substandard foods have increased.

Violations by big companies have dropped substantially while cases involving small companies and workshops increased, he said.

Some new crimes have emerged, including injecting Epinephrine Hydrochloride into pork which makes the pork look fresh and adds weight.

Last month, police arrested more than 110 suspects for selling pork from diseased pigs, confiscating over 1,000 tons of contaminated pork and 48 tons of cooking oil processed from the pork and other unclean meat.