In a factory workshop, cold noodles and seasonings are packed into bags on an assembly line in preparation for delivery to dinner tables across the country and the world.

These cold noodles, called ganmianpi in Chinese, are a specialty of Baoji, a city in Northwest China's Shaanxi province.

Xu Lu, office director of the Baoji Shangrun Food Company, said they receive more than 500 orders a day via e-commerce platforms, with each order averaging seven bags of noodles.

With a registered trademark, an industrial park and a special cold noodle industrial school, Baoji has turned the once handmade snack into a business worth more than 5 billion yuan ($782 million) a year.

The dish dates back as far as the Tang Dynasty (618-907), but it was during the Qing Dynasty (1644-1911) that imperial chef Wang Tongjiang returned to his hometown in Qishan county, Baoji, after retiring and taught fellow villagers how to make ganmianpi.

Today, the snack has become a local symbol.

Making the noodles is not simple. About an hour after the dough is made, it is repeatedly washed in water and then left for eight hours. After a series of steps, including fermentation, rolling, steaming and cooling, the dough is sliced into pliable but chewy noodles. Chili oil, gluten and vinegar are commonly used as seasoning.

Zhang Xinhuai started his ganmianpi business in the 1990s.

"All I had were a few tables and stools at a roadside stall," recalled the skillful noodle maker, who is now head of the city's ganmianpi industrial development and promotion association.

Zhang said that many small cold noodle businesses like his were a vital part of local lives.

In 2014, ganmianpihit online shopping platforms, attracting orders from across the country.

In the Baoji Panlong New Area, three companies have become the first to begin operations at the Baoji Ganmianpi Industrial Park. According to Li Peng, manager of the project, the park aims to become an industrial cluster combining cold noodle processing, e-commerce, logistics, technological development and tourism.

Last year, the Baoji ganmianpi industry reached the 5 billion yuan mark and now employs some 50,000 people across different sectors. The noodles have been exported to more than 20 countries and regions, including the United States, Canada, Japan and Australia.

A cold noodle industrial school was also set up in May at the Shaanxi Institute of Mechatronic Technology.

Yi Xunzhi, Party chief of the institute, said that in combination with the institute's professional competences, which extend to mechanics, electronics, automation, industrial robotics among other disciplines, the new school will be helpful for the integrated development of business, universities and research in the cold noodle sector.

According to Zhang Xinhuai, the city has registered the Baoji ganmianpi trademark with the aim of opening 10,000 chain restaurant outlets in 1,000 cities. It is also applying to register the snack as a protected geographical indication product. "We plan to expand the industrial chain with farms to produce raw materials like wheat and chili and create a highland for healthy food," he said.