Yogurt on shelves in a supermarket in Shanghai on Monday. [Photo/China Daily]

Insiders in the yogurt and jelly industries said on Wednesday that their businesses may suffer setbacks in the next few weeks as a result of two posts on Sina Weibo, the Chinese equivalent of Twitter, that have called on the public to avoid their products.

The messages, which were posted online on Monday morning, warned consumers that yogurt and jelly might contain industrial gelatin made from discarded leather shoes.

"It is certain that jelly companies will suffer sales declines in the next few weeks," Zhao Yanping, deputy secretary-general of the China Association of Bakery and Confectionery Industry, said on Wednesday.

"But so far, we cannot estimate the exact losses."

She blamed the situation on weibo, which she said hadn't provided enough evidence to support their accusations.

By Wednesday afternoon, various jelly enterprises had been ordered by local quality authorities to stop selling their products, according to a statement provided by the China National Confectionery Association.

The association will not rule out the possibility of making an appeal in court, the statement said.

But Yi Shenghua, a Beijing-based lawyer from Yingke Law Firm, said the case might not be heard.

"The people who wrote the posts didn't point out which yogurt brand or company has these troubles," Yi said. "So it will be difficult for yogurt enterprises to prove that a decline in their sales was caused by the information."

If no specific company or brand is found to be a victim of the accusations, the courts cannot, according to Chinese law, accept the case, he added.

On Tuesday, the China Association of Bakery and Confectionery Industry, China National Confectionery Association, China Dairy Industry Association and other associations affected by the incident responded to the accusations on their websites, saying: "It is impossible to add industrial gelatin to yogurt and jelly products."

China's food regulations say edible gelatin, a thickening agent, can be used as a food additive.

"Manufacturers will save less than 100 yuan ($15.8) if they make 1 metric ton of yogurt using industrial gelatin instead of edible gelatin. It's not worth it to do that," Song Kungang, chairman of the China Dairy Industry Association, was quoted by Xinhua News Agency as saying on Tuesday.

Edible gelatin is now not in jellies, largely because it can affect the product's taste and appearance, according to a statement posted on China Association of Bakery and Confectionery Industry's website.

Zhao Pu, a famous anchorman at China Central Television, posted the warning about yogurt and jelly in his weibo on Monday morning, saying that residents, especially children, should not eat those products. He did not explain why he had issued the statements.

Later, Zhu Wenqiang, a reporter from the Economic Observer, forwarded Zhao's post, saying that yogurt might contain industrial gelatin made from discarded leather shoes.

The two tweets aroused public concern immediately. The micro-bloggers deleted the information on Monday night.

Jin Qi, 25, a resident in Wuhan, Central China's Hubei province, said she will be careful when choosing yogurt.

By Tuesday, no complaints about food containing industrial gelatin had been made in Beijing, according to the local bureau of quality and technical supervision.

Liu Jianming, a professor specializing in communications at Tsinghua University, said customers' doubts are understandable, especially since food safety has become an issue of great concern in China.

"But the reporters used a vague way to disclose the information, which may do even more harm to society," he said.

Contact the writers at caoyin@chinadaily.com.cn and jinzhu@chinadaily.com.cn