The Yacón is a perennial plant grown in the Andes of Perú for its crisp, sweet-tasting tubers. The texture and flavour have been described as a cross between a fresh apple and watermelon which is why it is sometimes referred to as the apple of the earth. The tuber is composed mostly of water and fructo-oligosaccharides. It has recently been introduced into farmer's markets and natural food stores in the US.
Although sometimes confused with jicama, yacón is actually a close relative of the sunflower and Jerusalem artichoke. The plants produce propagation roots and storage tubers. Propagation roots grow just under the soil surface and produce new growing points that will become next year's aerial parts. These roots resemble Jerusalem artichokes. Storage tubers are large and edible.
Yacón plants can grow to over 2 meters in height and produce small, yellow inconspicuous flowers at the end of the growing season. Unlike many other root vegetables domesticated by the Inca (ulluco, oca), the yacón is not photoperiod sensitive, and can produce a commercial yield in the tropics.
Yacón provides for two nutritional products the yacón syrup and yacón tea. Both products are popular among diabetic people and dieters who consume these products because of its low sugar properties. The low sugar characteristic is due to the fact that the tuber is comprised of FOS (fructooligosacharides), a special type of fructose that the human body can not absorb thus it leaves the body undigested. The syrup is also a prebiotic which means that it feeds the friendly bacteria in the colon that boosts the immune system and helps digestion.
Yacón can easily be grown in home gardens in climates with only gentle frosts. It grows well in southern Australia, Tasmania and New Zealand, where the climate is mild and the growing season long. It has recently been introduced to the Philippines, and is now widely available in markets.
Propagation roots with growing points can be planted in a well-dug bed in early spring, near the time of the last expected frost. While aerial parts are damaged by frost, the roots are not harmed unless they freeze solid. Yacón is a vigorous grower much like Jerusalem artichokes. The plants grow best with fertilization.
After the first few frosts the tops will die and the plants are ready for harvest. It is generally best to leave some in the ground for propagating the following spring. Alternatively, the propagating roots can be kept in the refrigerator or buried away from frost until spring. While usable-sized tubers develop fairly early, they taste much sweeter after some frost.
The leaves of the yacón contain quantities of protocatechuic, chlorogenic, caffeic and ferulic acids, which gives tea made from the leaves prebiotic and antioxidant properties. As a result, some researchers have explored the use of yacón tea for treating diabetes and for treating diseases caused by radicals, e. g., arteriosclerosis.
In colonial times yacón consumption was identified with a Catholic religious celebration held at the time of an earlier Inca feast. In the Moche era, it maybe have been food for a special occasion. Effigies of edible food may have been placed at Moche burials for the nourishment of the dead, as offerings to lords of the other world, or in commemoration of a certain occasion. Moche depicted these yacón in their ceramics. .