Ajisen noodle shops have become embroiled in a soupy scandal, after media questioned the authenticity of their signature "white soup" base.

The Ajisen menu states "our confidence comes from the white soup, which is slowly boiled with all-natural materials." 

Media reports last Friday alleged the soup is not as natural as the noodle chain claim, and is not in fact boiled for 20 hours from pig bones. Ajisen's website boasts their nutritious soup contains "43 different nutrients and 1,600 milligrams of calcium for each bowl of soup."

 But during the soup crisis, the description has been deleted from its website. Reports also allege the soup costs less than one yuan per bowl.

Up to now, no customers have questioned the soup, according to an anonymous manager of Ajisen's Jianwai SOHO store. As for the production cost, he said "that's nonsense."

Ajisen (China) Holdings Ltd is based in Hong Kong and is Ajisen's sole franchisee in China. The chain started in Kyushu, Japan, and has 585 stores in China, with 32 in Beijing.

 Ajisen's publicity representative Hao Xiong said Friday "the soup base is a concentrate distributed by a Japanese company, but it is really boiled from pig's bones and fish."

A kilo of the concentrate makes 100 bowls of soup, Hao said.

Liu Hualin, chairman of Beijing Nutrition Consultant Association, doubts Ajisen's claims. "It's impossible for a bowl of naturally-boiled soup to have 1,600 milligrams of calcium. Grass can contain more than 30 kinds of nutrients." Liu said that Ajisen is only playing with the concepts, "and the recommended intake of calcium every day is no more than 1,200 milligrams, by the national standards."

"I'm a bit disappointed," said He Yawen, a customer, "I didn't know that; no wonder I feel thirsty sometimes after I eat the noodles."