Sweet potato is also known as yam or kumera. It is a root obtained from the plant with the same name: sweet potato. It weighs between 0.5 and 3 kg and shows an elongate shape, although some of them are almost spherical. There are sweet potatoes of a pale red colour, brownish-yellow or whitish, although the most widely cultivated varieties all over the world are those of red or pink rind and white flesh.

It has a sweet taste, due to its high sugar content. Sweet potatoes resemble potatoes, although they have no botanical relation.

Thanks to its combination of nutrients and its rich content of carbohydrates, one can say that it is a regenerative food of high energetic value. It has a high concentration of vitamin A, and significant percentage of vitamin E, C and folic acid. The latter is fundamental for the formation and maturation of red and white corpuscles, apart from its participation in the cellular multiplication and the tissues’ development.

The sweet potato (Ipomoea batatas) is also known as yam or kumera. It is an enlarged root obtained from the plant with the same name: sweet potato. It weighs between 0.5 and 3 kg and shows an elongate shape, although some of them are almost spherical. There are sweet potatoes of a pale red colour, brownish-yellow or whitish, although the most widely cultivated varieties all over the world are those of red or pink rind and white flesh.

It has a sweet taste, due to its high sugar content. Sweet potatoes resemble potatoes, although they have no botanical relation. Sweet potatoes have a fusiform shape, orange colour and a thicker and harder rind. There are two types of sweet potatoes, those with dry flesh and those with gelatinous flesh. They both have a white or orange flesh.

The sweet potato is characterized by its orange and sweet flesh, very suitable for roasting, making purees, cakes, soufflés and stuffing.

In some countries it is a basic food, since it is rich in carbohydrates, although the foliage is also eaten as a vegetable. Each 100 g of edible fresh produce provides with an energetic value of 84 kcal, greater than that of potatoes.

Its composition is similar to the potato’s but with some differences. The starch content is greater than that of potatoes. The proteins are scarce and the content of fats is even lower. It is one of the better digested vegetables. It is a regenerative food with a high energetic value. It has a great amount of vitamin A.

Once at home, sweet potatoes must be kept in a fresh, dry, dark place with good ventilation, without wrapping, where they can be stored for a week. The environmental temperature must not exceed 15ºC, since they may ferment or germinate at higher temperatures. Once cooked, they can be kept in the fridge for a week and even longer if they are frozen.

They are very popular in Creole cooking. They are always eaten cooked; the best way is to roast them in the oven. They can also be eaten fried or in puree. They go well with cinnamon, honey, coconut, lime and nutmeg, and are a good garnish for pork and poultry.

Jam, puddings, pies, cakes, soufflés and even alcoholic drinks are made of sweet potatoes, given their wealth in amylaceous and sweetened substances.

The optimal conditions for sweet potato storage are between 11-15ºC and 80-85% of relative moisture, thus lasting for several months. In the Spanish Mediterranean coast it is very frequent to put sweet potatoes under curing in the cultivation land, leaving them to dry once harvested.

The plant belongs to the Convolvulaceous family and its scientific name has several synonyms like Convulvus batatas L., Batata edulis Choisy and Ipomea batatas Lam.

It is a perennial plant, although it is cultivated as annual. It has cylindrical and climbing stems. They are crawling stems that extend up to 2-3 m long. The leaves are alternate, well-developed and usually heart-shaped. The leaves’ petiole is long, up to 20 cm. The limb is quite developed. The leaves are of a dark green colour. The flowers are bell-shaped, of great size and reddish, white or violet colour. The pollination is usually entomophilous. The multiple fruit is capsular, with 1-5 seeds/fruit of black colour and triangular and angular shape.

The root system is the most important part of the plant, since it is the main reason for its cultivation. It has numerous forked and fibrous roots. The base of some of these roots undergo a considerable enlargement varying in shape, weight, colour and fleshliness according to the varieties. They store reserve substances, chiefly in the form of starch, with a high content in carotene and vitamin C and an appreciable percentage of proteins. The weight of the tubercle ranges from 200 g to 6 kg.