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Yacon (Polymnia sonchifolia) is a distant relative of the sunflower, but this Andean crop is grown not for seed but for its edible tubers.1 These enlarged storage organs have a clean, crunchy crispness, set off by a refreshing sweetness. They have been described as being like a fresh-picked apple with mild, sweet flavor reminiscent of watermelon.

Yacon (pronounced ya-kon)2 should prove agreeable to a wide range of palates, and it also has a future as an industrial crop. Most other roots and tubers store carbohydrate in the form of starch—a polymer of glucose; yacon, on the other hand, stores carbohydrate in the form of inulin—a polymer composed mainly of fructose.3 Yacon, therefore, may possibly be a fructose-sugar counterpart of sugar beets.

Yacon tubers also may have potential as a diet food. The human body has no enzyme to hydrolyze inulin, so it passes through the digestive tract unmetabolized, which means that yacon provides few calories. This could be an attractive marketing feature to dieters and diabetics.

In addition, the main stem of the young plant is used as a cooked vegetable. The species also shows promise as a fodder crop because the leaves contain 11–17 percent protein on a dry-weight basis.

From Colombia and Venezuela to northwestern Argentina, yacon is found at elevations below about 3,300 m. Children, in particular, consider its roots a special treat. In some areas, almost everyone has a few plants in the family garden plot. Much is grown in northern Argentina, for instance, and in Latacunga, Ecuador, yacon is sold in large quantities, especially on the traditional Day of the Dead.4 On the other hand, in other areas, it is seldom abundant in markets; in some places it is almost unknown.

1 Strictly speaking, these are not tubers, but an integrated mass of root and stem.
2 In Ecuador it is frequently called “jicama.” Internationally, that name is used for another plant (see page 39).
3 Yacon shares this form of carbohydrate storage with most members of the Compositae, or sunflower family. Rarely, however, does inulin appear so abundantly or in so pure a form.
4 Information from R. Castillo.

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