Yang Hui, a 29-year-old white collar worker in Beijing, said her next online purchasing plan is to buy some United States-imported pistachio nuts and Yunnan ham, neither of which are commonly seen in the capital city's supermarkets.

"Although there are abundant and various types of foods available in supermarkets, the number of imported food and regional specialties is limited and sometimes the prices are high," said Yang. "I like to purchase food online because it allows me to buy food without geographical limitation and enables me to enjoy the best prices in the market."

Yang said she will spend about 4,000 yuan ($635) every year on online food shopping, mostly to buy specialties, for instance, pineapple cake from Taiwan and dates and nuts from Xinjiang Uygur autonomous region.

"I am a person who enjoys trying food from different regions. I think it is a way to know more about different places," said Yang.

For many Chinese gourmands like Yang, the development of online shopping platforms such as Taobao allows them to enjoy various food from a variety of regions. The range spans widely from expensive products such as bird's nest, which cost thousands of yuan a kilogram, to the very cheap at less than 10 yuan per unit.

"Some food can only be produced and traded in certain areas but we cannot visit anywhere we want so the online platform is a useful tool to satisfy our needs," said Yang.

There is no figure to show exactly how many people buy food online annually. The figure from Taobao.com, one of the largest online platforms, suggests about 10.5 percent of the population in Shanghai bought snacks online in 2011, the highest proportion among different provincial regions in China. More than 60 percent of them were female. The population of Shanghai reached 220 million in 2010.

The recent seven-episode documentary series A Bite of China showed how big the market is. It showcased regional Chinese food in broadcasts at 10:30 pm from May 14 to May 22.

The TV show stirred up a wave of culinary curiosity about buying snacks online. Many in the audience were impressed by the series and rushed to Taobao to search for the food featured after each episode ended.

Taobao, the largest online platform operator in China, said the daily peak time for online snack purchasing shifted from 11 am and 4 pm to about 11pm at night.

"We have seen sales volume rise by 50 percent month-on-month and more than 90 percent of customers are from outside Jiangmen," said Chen Baizhong, general manager of Lingnan Xinbaotang Mandarin Peel Production Co in Jiangmen, Guangdong province. Chen's company has produced mandarin peel in Jiangmen for more than 100 years and was mentioned in A Bite of China.

"We never expected there would be such a big growth in sales," said Chen.

The figure from Taobao shows a total of 5.84 million people searched for snacks and regional specialties and 7.2 million orders were confirmed under related categories from May 14 to May 18. Some little known food introduced in A Bite of China caused search numbers to jump by more than 100 times month-on-month.

The booming e-commerce businesses and increasing number of people buying food online helps companies to broaden their consumer bases and increase brand awareness around the country.

"The high consumer volume of Taobao is one of the main reasons we opened an online store at Taobao in 2009," said Chen. "The e-commerce platform has become a main channel for customers to know about local specialties."

Despite the online food trading businesses booming, people still express some concerns over food quality and safety.

"Sometimes it is hard to identify fake products. I wanted to buy some ham produced in Yunnan province after watching the documentary. However, I found suddenly there were many vendors selling ham. I am sure there will be some fake products but I cannot tell which they are," said Wang Ming, a resident of Shanghai. "So I gave up on my plan to avoid being cheated."