Sweet potato is one of the world’s most important food crops in terms of human consumption, particularly in Sub-Saharan Africa, parts of Asia, and the Pacific Islands. First domesticated more than 5,000 years ago in Latin America, it is grown in more developing countries than any other root crop.
Despite its name, sweet potato is not related to the potato. It is a root, not a tuber, and belongs to the morning-glory family. Many parts of the plant are edible, including leaves, roots, and vines, and varieties exist with a wide range of skin and flesh color, from white to yellow-orange and deep purple.
Sweet potato grows in marginal conditions, requiring little labor and chemical fertilizers. It is a cheap, nutritious solution for developing countries needing to grow more food on less area for rapidly multiplying populations. It also provides inexpensive, high-protein fodder for animals.
SWEET POTATO FACTS AND FIGURES
Worldwide, sweet potato is the sixth most important food crop after rice, wheat, potatoes, maize and cassava. But in developing countries, it is the fifth most important food crop. More than 105 million metric tons are produced globally each year; 95% of which are grown in developing countries.
Sweet potato can grow at altitudes ranging from sea level to 2,500 meters. It requires fewer inputs and less labor than other crops such as maize, and tolerates marginal growing conditions (e.g., dry spells, poor soil).
Sweet potato comes in varieties with skin and flesh color that range from white to yellow, orange, and deep purple. Orange-fleshed sweet potato is an important source of beta-carotene, the precursor to Vitamin A. Just 125g of fresh sweet potato roots from most orange-fleshed varieties contain enough beta-carotene to provide the daily pro-vitamin A needs of a preschooler.
Sweet potato is also a valuable source of vitamins B, C, and E, and it contains moderate levels of iron and zinc.
Nutritionists in the USA are exploring the potential cancer preventing properties of the anthocyanins, which are present in purple-fleshed sweet potato.
Though its origins lie in Latin America, Asia is now the largest sweet potato-producing region in the world, with figures showing over 90 million tons produced annually. China is the world’s biggest producer and consumer of sweet potato, where it is used for food, animal feed, and processing (as food, starch, and other products).
The importance of sweet potato as a food crop is growing rapidly in some parts of the world. In Sub-Saharan Africa, it is outpacing the growth rate of other staples.
Sweet potato is used for both human consumption and as a healthy, cheap source of animal feed. Recent studies suggest that animals fed on high protein sweet potato vines produce less methane gas than with other feed, potentially contributing an important reduction in harmful global emissions.
Sweet potato has a long history as a life saver. The Japanese used it when typhoons demolished their rice fields. It kept millions from starvation in famine-plagued China in the early 1960’s and came to the rescue in Uganda in the 1990’s, when a virus ravaged cassava crops.
SWEET POTATO PROCESSING AND USES
Many parts of the sweet potato plant are edible, including the root, leaves, and shoots.
Sweet potato vines also provide the basis for a high-protein animal feed.
Sweet potato use has diversified considerably over the last four decades. With high starch content, it is well suited to processing and has become an important source of raw material for starch and starch-derived industrial products.
Added value for farmers comes from a variety of products and ingredients made from sweet potato root including flour, dried chips, juice, bread, noodles, candy, and pectin.
New products include liquors and a growing interest in the use of the anthocyanin pigments in the purple varieties for food colorings and use in the cosmetics industry.
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