New processing tech to unlock potential of China's potato industry

KUNMING, Dec. 19 (Xinhua) -- "Potato-turned rice", a rice-shaped starch product made from potatoes using a new processing technology, is undergoing initial production and sales tests in southwest China's Yunnan Province.

The production line started operation in November and has been running smoothly for about a month. The new product has the potential to turn potatoes, which have good yields and wide adaptability but a short storage life, into a popular staple food in China, thus helping the country ensure food security.

RESHAPING THE STARCH CHAIN

The production line in Qiaojia County, in the city of Zhaotong, Yunnan Province, is the latest achievement of polymer physical chemist Wu Qi, an academician of the Chinese Academy of Sciences. He and his research team built the plant and put it into operation after more than five years of research and development.

The team focused on the extrusion recombination technology of plant polysaccharides and protein composite systems, with the aim of making tuber crops a staple food in China and introducing the processing technology to the market.

Starch is the main substance used by plants to store energy, and is composed of long chains of sugar molecules connected together. Starch macromolecule chains have two major forms: the linear amylose, and the branched amylopectin.

Dining tables around the world feature various staples composed of starch foods, such as rice, wheat, potatoes and corn. However, most Chinese people do not view potatoes as a staple food like rice and wheat, treating them more as a vegetable ingredient instead.

The processing technology changes the properties of potato starch macromolecules at a physical level to reshape the starch chain. It integrates macromolecular physics theory, food macromolecule processing, and polymer extrusion and granulating technologies.

Agronomist Deng Yong, director of an agricultural service center in the county, said there are slightly more branched chains in potato starch than in rice starch, resulting in a difference in food texture. Changing the configuration of the potato starch chains results in a food product that is not so soft, and is therefore more appetizing to consumers, as well as being more convenient to store with a longer shelf life.

The potato-turned rice has been processed at high temperature and high pressure, so there is no need to wash and soak the rice. It can be cooked in an ordinary electric rice cooker like real rice, and the amount of water and cooking time required are far less than those of rice, he added.

INDUSTRY POTENTIAL

The mountainous city of Zhaotong is one of the main potato-producing areas in Yunnan, with a climate and environment very similar to the Andes Mountains in South America, where potatoes originally come from. The city was awarded the title of "Potato Plateau Seed Potato Capital of the World" by the World Potato Congress in 2020.

Zhaotong currently boasts a potato planting area of about 158,000 hectares, with a yield of 3.5 million tonnes and a total output value of about 10 billion yuan (about 1.37 billion U.S. dollars).

According to Li Yulin, the general manager of the company running the production line, the preliminary estimate shows that 2.5 tonnes of potatoes can be processed into 1 tonne of potato-turned rice, with the output value increasing by more than 10 times.

The production line is expected to process about 2,500 tonnes of fresh potatoes per year, producing 1,000 tonnes of potato-turned rice, achieving an output value of about 30 million yuan, he added.

Deng said the processing technology is expected to promote potato planting in mountainous areas, as well as the planting and deep-processing of other crops, completing the industrial chain of mountain agriculture.

He added that potatoes can be planted in most parts of the country, while processing technology has big potential for assisting poverty alleviation efforts through sci-tech progress.

The first batch of products has already been put on trial sale in the local market, and the feedback shows that middle-aged and elderly people are interested.

ENSURING FOOD SECURITY

According to Wu Qi, the lead scientist of the development team, food security is based on three major elements: the area of arable land; the yield per unit area; and strategic reserves. The potato-turned rice has many advantages in these three areas, and can therefore contribute to ensuring food security.

Compared to the average yield of 12 tonnes per hectare for rice, the potato yield can reach over 30 tonnes per hectare. Potatoes can be grown in various regions across China, including mountainous areas and plains, and they have strong drought resistance.

After the processing, the potato-turned rice can be stored at low cost at room temperature for a long time without the need for ventilation, or temperature and humidity control. This is unlike fresh potatoes, which have a short storage life and high storage cost.

The production line in Yunnan is the latest case of China using potatoes to promote food security. In 2016, the country's agriculture ministry announced that potatoes will be promoted as staple food products for industrialization.

In recent years, the sowing area of potatoes in China has been kept at about 4.67 million hectares, with an annual output of nearly 90 million tonnes, with the output ranking first in the world for many years.

Official data show that China's cumulative grain imports in 2023 stood at 161.96 million tonnes, while the total grain outputs were 695.41 million tonnes in the same year.

During the annual Central Economic Work Conference, held last week to outline priorities for the Chinese economy in 2025, Chinese leaders decided that efforts should be focused on areas including the stable production and supply of grain and other major agricultural products, as well as the promotion of the agricultural industry according to local conditions to increase farmers' incomes.