Sweet Potato Ipomoea batatas Remains of sweet potato have been found in Peruvian caves known to have been inhabited by Man since around 8,000BC. The tuber of a convolvulus vine from the same family as the ‘Morning Glory’, it is thought to have been brought under cultivation by about 200-100BC, well before the time of the Incas, becoming one of the staple carbohydrates in the tropical Americas. Its use as a food spread eastwards to the Caribbean islands and it is thought that early trans-Pacific migration took it westwards into the Pacific Islands, reaching as far as New Zealand by the early 13th century. This theory would seem to be supported by the fact that many of the words used to describe the tuber in the region differ only very slightly from the original Peruvian name, kumara. Discovered by Colombus’ expedition of 1492 in Haiti, where it was called batatas by the local population, the sweet varieties soon found favour with the Spanish explorers. They took it with them to the Phillipines from where the Portuguese transported it to the East Indies. It was also via the Phillipines route that the sweet potato was to find its way into China: a famine in the Fujian Province in 1593 prompted an expedition to the islands in search of food plants; the ships returned a year later bearing, amongst others, the sweet potato. It was such a success in the province that when it travelled onwards to Japan in the 18th century the Japanese called it the ‘Chinese potato’. It is believed that the slave trade was responsible for the arrival of the sweet potato in Africa, where it was accepted as another type of yam, which it resembles. Europe and the more northern countries were a different matter, however.Unlike its namesake, the white potato, a solanaceae tuber which grows well in cooler climates, the sweet potato only thrives in warmer regions keeping it firmly in the novelty food bracket until the more efficient and speedier trans-global transportations metods of modern times. Nutritionally, the sweet potato is a good source of potassium, a useful source of vitamin C and the deeper orange the potato, the more beta-carotene it provides, which may help to prevent certain forms of cancer. 100g raw gives, on average, 91 kcalories energy, 1.2g protein, 0.6g fat, 21.5g carbohydrate, 19mg sodium, 320mg potassium, 22mg calcium, 13mg magnesium, 0.7mg iron, 0.16mg copper, 4000-1200µg carotene, 0.10mg vitamin B1, 0.06mg vitamin B2, 1.2mg niacin, 25mg vitamin C. 100g, boiled in salted water, gives 84 kcalories of energy, 1.1g protein, 0.3g fat, 20.5g carbohydrate, 11.6g sugars, 2.3g fibre, 23mg calcium, 0.7mg iron, 32mg sodium, 660µg vitamin A (beta carotene), 0.07mg Thiamin, 17mg vitamin C.