category: food/groceries: vegetables: tuber vegetables

Sweet potato, Spanish potato, bot.: Ipomoea batatas, de.: Süßkartoffel, Batate, Weiße Kartoffel, Knollenwinde, fr.: batate, patate douce, artichaut des indes, it.: patata americane, patata dolce, es.: batata

Origin and history of sweet potatoes

The Sweet potato belongs to the botanical family of bindweed (lat.: Convolvulaceae). Sweet potatoes are thought to have originated in Middle and South America. Nowadays they are cultivated in most countries with tropical, subtropical and temperate climates. China is the largest producer of sweet potatoes worldwide. With 100 million tons per year it produces about one third of the world production.

Plant description of sweet potatoes

Sweet potatoes are perennial plants. The upper part of the plant grows as a herbaceous vine. The large tuberous roots look similar to those of potatoes. They are also often confused with Jerusalem artichokes and yams. Botanically they are not related with either plant.

Sweet potatoes are available in different sizes and shapes: long, round or spindle-shaped. The ends are usually tapered. The tubers grow up to 30 cm long and weigh about 1 kg on average, with some reaching a weight of up to 3 kg. Their skin colour varies from red and brown to yellow and white. The flesh may be red, brown, yellow or white as well.

Properties of sweet potatoes

Sweet potatoes contain a lot of sugar, which gives it a sweet taste. Apart from that they consist mainly of starch, the so-called sweet potato starch. Depending on the climate and growing area sugar and starch content vary highly. In countries with a tropical climate the sugar content is much higher than the starch content.

Storage of sweet potatoes

Sweet potatoes may be grown year-round. Because of its high water content the tubers cannot be stored very long. Perfect storage conditions are like those of potatoes, in cool, dry and dark cellars. The temperature should not drop below 5°C. Alternatively sweet potatoes may be stored in dry peat.

Use of sweet potatoes

In many native countries of the sweet potato, it is an important and diverse staple food. Its importance is comparable to that of potatoes in many European countries, as are its cooking properties. Sweet potatoes are often used as a source of carbohydrates in hot vegetable curries. They are served boiled or roasted with spicy sauces or used for bread baking. In some countries leaves and young sprouts growing from the roots are eaten as vegetable. In others leaves and sprouts are used as animal feed. Sweet potatoes are often oven-baked. To prepare them, they are peeled, pierced several times with a fork, rubbed with oil, and wrapped in aluminium foil. A delicious purée can be prepared from oven-baked sweet potatoes and cream.

In food industry sweet potatoes are used for the production of flour and starch (sweet potato starch contains between 24 and 26% starch). Other industrial products made from sweet potatoes include glucose syrup, industrial alcohol, brandy and other alcoholic beverages.