A dairy industry expert on Tuesday dismissed concerns that laosuannai, a kind of solid yogurt, contains industrial gelatin.

"Yogurt manufacturers would have just saved tens of yuan per tonne if they had used industrial gelatin instead of edible gelatin. It was not worth doing that," said Song Kungang, head of the China Dairy Industry Association.

"Production permits were not easy to come by. I don't think yogurt companies dare to substitute edible gelatin with industrial gelatin," Song said.

Concerns reignited over the country's dairy product safety after Zhao Pu, a China Central Television anchor, posted a microblog entry, warning that people, especially children, should not eat solid yogurt and jelly.

"The inside story is horrible," Zhao wrote in the post, citing an investigation by a journalist. But Zhao deleted related messages later Monday.

Zhao's main concern centered on whether industrial gelatin, which is a forbidden additive in China and made from leather products, had been added into solid yogurt and jelly.

Song said yogurt with industrial gelatin can easily be detected through hydroxyproline tests.

"The cost of crime is too high in this case, so I don't buy that story," Song said.

In recent years, authorities have stepped up supervision and regulation of the dairy market after a slew of safety scandals. The number of dairy companies plunged to 716 at the end of last year, from a peak of 1,500 to 1,600.

Some big yogurt and jelly firms have stood out in assuring the safety of their products.

The Beijing News reported Tuesday that an engineer from Qinqin Inc, a leading jelly producer, said the company uses carrageenan as a thickener in its products.

Carrageenan is an edible additive that makes jelly fresh, crisp and transparent, while gelatin does not have the same effects, the newspaper quoted the engineer as saying.

A manager at a state-owned dairy maker also responded that the company had never used industrial gelatin in solid yogurt.

The manager said small companies may use industrial gelatin, but big ones were very unlikely to do so.

"We strictly conformed to national standards when adding food additives into our products. Consumers can rest assured," the manager said, adding that he hoped the government could do more to regulate the sector.

Edible gelatin is mainly collagen extracted from animal skin and bones. It is good for health and there is no need to worry about safety issues, Song noted.

He added that people should report to authorities in a timely manner if they have evidence that some companies did use industrial gelatin in production.