Popular Science Outreach Outline on Potato Staple Food Products and Industrial Development
Chinese Academy of Agricultural Sciences
June 2015
1.Origin and spread of the potato and how it is eaten abroad
Origin and global spread of the potato:At present, there are two centers of origin of the potato recognized worldwide: the cultivated potato originated in the basin center at the border of Peru and Bolivia, and in the regions along the Andes foothills in Peru, Bolivia and Uruguay in South America. Wild species originated in Central America and Mexico.
The worldwide spread of the potato first went from South America to Europe, by two routes: one was in 1551, when the Spaniard Valdevii brought tubers to Spain and introduced them to the King; in 1570 they were introduced and planted in the south, and later spread to most European countries as well as some countries and regions in Asia; the other was from 1588-1593, when the potato was introduced to England and widely planted across the three British Isles and the Nordic countries, and later introduced to British colonies and North America.
How potatoes are eaten abroad:In foreign countries, potato food consumption accounts for a relatively large proportion, and the processing industry is relatively developed. In developed countries such as Europe and the United States, potatoes are mostly consumed as a staple food and are quite favored by consumers, having become one of the indispensable foods in daily life. In the United States, the output and consumption of processed potato products account for about 76% of total production; there are as many as more than 90 kinds of potato foods, and potato foods can be seen everywhere on the market. The average annual consumption of potato foods per person in that country is 30 kg, and together with the amount processed into starch, feed and alcohol, this accounts for about 85% of potato production. At present, the variety of processed products using potatoes as raw material in the United States has exceeded 100. Russia's annual per capita potato consumption is 100 kg, almost equal to its grain consumption. Japan's total annual potato output is 3.512 million tons; in Hokkaido alone, about more than 2.59 million tons of fresh potatoes are used for processing each year, accounting for 86% of its total output; among these, about 2.05 million tons of potatoes are used for processed foods and starch, accounting for 72.4% of total output. The processed products mainly include frozen potato products, potato strips (chips), mashed potato, mashed potato composite products, starch, and deep-processed products such as whole potato flour, as well as complete-price feed. Germany imports more than 2 million tons of potato food each year; the main products include dried potato cubes, shreds and puffed potato cubes, and the average annual consumption of potato food per person is 19 kg; the United Kingdom's annual per capita potato consumption is nearly 100 kg, and the country uses 4.5 million tons of potatoes for food production each year, among which frozen potato products are the most numerous; France is the main producer of fast-food mashed potato, reaching more than 20,000 tons as early as the early 1970s; there are 12 large enterprises in the country producing potato foods, with per capita consumption of potato products at 39 kg.
2.Spread, cultivation and consumption of the potato in China
Spread of the potato in China:Cultivation of the potato in our country began during the Wanli period of the Ming Dynasty (1573-1620). The Beijing-Tianjin region may have been one of the earliest areas in China to grow potatoes, with a cultivation history of nearly 400 years. In the early 19th century, Yunnan, Guizhou, Shanxi and Gansu in our country already had large-scale planting and considerable output. At present, the provinces with relatively large national planting areas are Gansu, Inner Mongolia, Sichuan, Guizhou and Yunnan.
Cultivation, processing and consumption of the potato in China:Our country has a vast territory, and potato cultivation is spread across the whole country, with a planting area of about 80 million mu and a relatively low average yield of about 1,200 kg/mu. Based on different resource conditions, various regions have formed corresponding cultivation zones: the northern single-crop zone, the central double-crop zone, the southern winter-crop zone, and the southwestern mixed single- and double-crop zone.
In the course of potato industry development, 6 advantageous planting regions have been formed: namely the Northeast advantage region for seed potatoes and starch-processing raw materials; the North China advantage region for seed potatoes and food-processing raw materials; the Northwest advantage region for high-quality edible and processing raw materials; the Southwest advantage region for edible and processing raw materials; the Central Plains advantage region for early-maturing vegetable-use and export; and the South advantage region for winter-crop vegetable-use and export.
Potato processed products are mainly in four major categories: potato foods (potato chips, strips, mash, cubes, puffed foods, and traditional foods such as steamed buns, noodles and rice noodles), potato vermicelli, fine vermicelli and potato starch (including modified starch and whole potato flour). At present, due to the lack of modern storage equipment and scientific processing technology, the annual national loss of potatoes is 25-30%, and the remaining 70-75% is also basically used for fresh eating or processed into fine vermicelli, vermicelli and starch, with insufficient processing depth, low economic benefits and limited digestion capacity. Potato vermicelli processing is a traditional potato processed product, but there are also many problems in processing quality and brand development. The proportion of potatoes used for starch processing is small, and compared with countries where potato production is relatively developed, there is still a large gap.
In our country, potatoes are mostly limited to fresh storage, fresh transport, fresh sales and fresh eating. In the traditional dietary structure, more than 95% of potatoes are eaten fresh as vegetables and are seldom eaten directly as a staple food. In recent years, processed potato foods have become very popular in our country. McDonald's and KFC foods using potato strips and mashed potato as basic raw materials have already occupied half of our country's fast-food market, while other fried potato chips, puffed foods and other processed potato products imported through various channels are also continuously growing. With people's understanding of healthy foods and demand for food diversity, as well as the publicity and guidance of various media, potato foods will gradually become one of the staple foods that regulate and enrich people's daily food structure in both urban and rural areas of our country, and will occupy a place in the daily dietary structure.
Main potato varieties grown in our country:At present, there are 82 potato varieties with an annual planting area of more than 100,000 mu nationwide, and 30 varieties with more than 500,000 mu. Among them, Kexin No. 1 has the largest planting area, about 13 million mu, followed by Mira, Favorita, Longshu No. 3, Weiyu No. 3 and others.
3.The important significance of developing potato staple food products and the industry in our country
The development of potato staple food products and the industry means processing potatoes into staple food products such as steamed buns, noodles and rice noodles that suit the consumption habits of Chinese people, realizing the transformation from consumption as a side food to consumption as a staple food, from raw material products to industrialized series of finished products, and from subsistence consumption to nutritious and healthy consumption. Experts estimate that by 2020, more than 40% of potatoes will be consumed as a staple food. The development of potato staple food products and the industry will adhere to the promotion principle of “one no and three persistences”: “one no” means not competing with the three major staple grains of wheat, rice and corn for water and land; “three persistences” means persisting in giving consideration to both staple food development and comprehensive utilization, persisting in combining government guidance with market determination, and persisting in unifying overall advancement with key breakthroughs, gradually realizing the specialization of potato production varieties, regionalization of planting, mechanization of production, industrialization of operations and staple-foodization of products, and forming a new pattern of coordinated development of potatoes and grains.
Advancing “potato staple food products and industrial development” is mainly based on the following considerations: First, it responds to everyone's need to “eat enough, eat well and eat healthy.” Potatoes are rich and comprehensive in nutrition, low in fat, high in protein quality and low in calories, which is conducive to the staple food needs of people in a moderately prosperous society to eat enough, eat well and eat healthy. Second, it can promote the adjustment of planting structure according to local conditions and scientifically develop and utilize food resources. Our country's cultivated land resources are seriously scarce, water resources are unevenly distributed, and the pressure on the ecological environment is constantly increasing. In regions such as the Northwest with water shortages, North China with severe groundwater overdraft, and the South with abundant winter fallow field resources, there is an urgent need to transform the development mode and optimize the planting structure. Potato production has good effects in saving water, land, fertilizer and pesticides, and can serve as a major alternative crop for agricultural structural adjustment. Third, advancing the strategy of “potato staple food products and industrial development” is an important supplement to ensuring absolute grain security. Potatoes played an important role in solving people's subsistence problem in the past, and today, when the importance of food security is even more prominent, advancing potato staple food products and industrial development has become an inevitable choice. Fourth, it is conducive to increasing farmers' income and promoting the optimization of industries within agriculture. The potato industry chain is long; advancing potato staple food products and industrial development and developing deep processing of potatoes will help increase farmers' income and improve agricultural efficiency.
Potatoes are cold-resistant, drought-resistant and barren-resistant, with a short growing season. Their minimum water requirement for growth is only 350 mm, making them the best rain-fed high-yield crop suitable for planting below 400 mm, while wheat and rice require 450 mm and 500 mm respectively. Therefore, in the vast area of about 200 million mu including the North China funnel area, the Three-North arid area and the southern winter fallow fields, carrying out planting mode and structural adjustment and expanding the planting of cold-resistant, drought-resistant and barren-resistant potatoes is an important part of adjusting the planting structure, achieving sustainable development and ensuring national food security. Planning according to the situation and advancing potato staple food development is conducive to improving the dietary structure and meeting the people's desire to enhance physical health; acting according to the situation and advancing potato staple food development is conducive to tapping production potential and opening up a new way to ensure national food security; following the situation and advancing potato staple food development is conducive to alleviating the pressure on resources and the environment and achieving sustainable agricultural development.
II. Nutritional Value of the Potato
Potatoes contain rich nutrients, which can be confirmed by the laudatory names given to potatoes by some countries, such as “underground apple,” “second bread” and “precious crop.” The protein content in potato tubers is generally 1.6-2.1%, and high-protein varieties can reach 2.7%. Its quality is close to animal protein and comparable to eggs; it has a high digestible component and is easily absorbed by the human body. It is rich in 18 amino acids, including all the essential amino acids for the human body. Generally speaking, potato tubers contain 0.6-0.8% dietary fiber, 2-12 times higher than rice, millet and wheat flour, and about 0.2% fat, belonging to low-fat foods. The starch content is 13.2-20.5%, with both amylose and amylopectin structural forms. Potato tubers are rich in minerals and belong to alkaline foods, capable of neutralizing the acidity of acidic foods and maintaining the acid-base balance in the human body. In 100 grams of fresh potatoes, there are about 342 mg of potassium, 8 mg of calcium, 0.8 mg of iron and 40 mg of phosphorus. Compared with other vegetables and fruits, the vitamin C content of potato tubers is 6 times that of apples, about 27 mg, which is absent in most grains. An adult eating 0.5 kg of potatoes a day can meet the body's entire requirement for vitamin C. The carotene content is also relatively high at about 30 mg. In addition, potato tubers also contain rich B vitamins.
1.Special nutrition of the potato:The potato is a high-quality infant food. At present, common baby complementary foods include mashed potato, potato cubes and potato biscuits. Such foods are rich in nutrition, simple to cook, provide a good feeling of fullness after eating, and are easy for infants to digest and absorb. Potato tubers are rich in vitamin E, vitamin C, potassium and others, and are important foods for anti-aging and health preservation. Colored potato varieties are also rich in anthocyanins, a strong antioxidant that can scavenge the harm of free radicals and has a relatively good anti-aging effect. In addition, the potato is also a body-beautifying food; its rich dietary fiber increases people's feeling of fullness, reduces the intake of large amounts of food, and can also promote the metabolism of body fat, which is conducive to maintaining a fit body.
2.Medicinal value of the potato:The medicinal value of the potato is mainly reflected in two aspects: on the one hand is its own medicinal value. Because the potato has the effects of tonifying the middle and replenishing qi, harmonizing the stomach and strengthening the spleen, and reducing swelling, external application can treat fractures and injuries, headache, rheumatism and other symptoms; it is also a relatively good rehabilitation food for cancer patients. Eating whole potato flour or mashed potato can stop vomiting, aid digestion, maintain epithelial cells, prevent the occurrence of epithelial tumors, alleviate the toxicity of carcinogens in the body, and can restore already cancerous cells to normal; because it is rich in vitamins and anthocyanins, it can prevent diseases related to free radicals, including cancer, heart disease, premature aging, stroke and arthritis. On the other hand, its own physical properties also have great potential in medicine. For example, potato starch is mainly used to make sugar coatings, capsules and dental materials, bone-setting adhesives, medical glove lubricants, radioactive nuclide carriers for diagnosis, and so on. Because of its low-calorie characteristics, potato starch can be used in medicines for treating certain special diseases such as vitamins, glucose and sorbitol. Potato starch can also be made into starch sponge, which after disinfection has a hemostatic effect when placed on wounds.
3.Value of different potato varieties:Different potato varieties have different traits; the color of the tuber flesh alone includes white, yellow, purple and pink. On the market, potato varieties with white and yellow tuber flesh are the majority, while purple and pink (red) potatoes are relatively rare; the above two kinds of potatoes are collectively called colored potatoes. At present, purple potato varieties include Ziyang and Purple Rose, and red potato varieties include Hongmei and Hongyun. Colored potatoes are not only higher in nutritional content than ordinary potatoes, but because the tubers contain polyphenolic compounds such as sinapic acid, coumaric acid, flavonoids, as well as anthocyanins and selenium, they have relatively strong health-care functions and medicinal value.
III. Existing Folk Potato Staple Food Situations
1.Traditional Chinese potato staple food recipes:Potatoes have a cultivation history of more than 400 years in our country. People in different places process potatoes into different forms of staple food products according to different dietary habits, mainly including stir-fried potato, pot-crust potato, pan-baked potato, roasted potato, copper-pot potato braised rice, potato pancake, potato fritter, potato ball, potato cake, potato rubbed noodles, shredded potato fried rice, fried potato, boiled potato, and naked oat potato pancake.
2.How to eat potatoes more nutritiously: Potato staple foods come in diverse forms, and their processing methods are also varied. In addition to steaming and boiling, they also include pan-frying, stir-frying, braising, deep-frying and stewing. From the perspective of health and nutrient retention, steaming is recommended first; steaming potatoes better preserves the original flavor and nutrition of the food, but steamed food has a single taste, and seasonings can be added after steaming. Methods such as pan-frying, stir-frying, braising and deep-frying have richer tastes than steaming and boiling, but they are all cooked in the environment of vegetable oil or animal fat, and high temperature as well as the involvement of fatty acids easily destroys the original nutrients of the food.