Yacon

Smallanthus sonchifolius

Fructooligosaccharide-rich root, sweet but largely undigested

Yacon tastes sweet, but much of that sweetness comes from fructooligosaccharides that pass through undigested, so this root vegetable carries little energy for its bulk. Crisp and cool, it is best peeled and eaten raw or shredded into a salad. Because those sugars ferment in the large intestine, a large helping at once can leave the belly gassy, so start with a small portion. Set out plants in May or June and lift the roots from mid-October. The edible part is the storage root; leaf tea is not recommended, as its safety has not been established.

Year-Round Calendar

Sowing

Harvest

Where It Grows

Origin Major producer Wild population Latitudes at 18–25℃ Zoom and pan to explore · temperatures are rough zonal averages

Origin The valleys of the eastern Andean slopes are its place of origin and remain a growing area today. The Cajamarca and Ancash areas are the best known.
Origin In the eastern Andean valleys it forms a single native range continuous with Peru.
Wild population Traditional local strains survive in the Andean valleys.
Major producer It was brought in during the 1980s and cultivation began in several prefectures, with growing areas scattered about.

It is native to the valleys of the eastern slopes of the Andes, at 1,000–3,000 m above sea level, and it is a root vegetable that has been grown there since before the Inca. In the late twentieth century it spread by way of New Zealand to Japan, Korea and Brazil, and because world trade in it is still small, no country-by-country production figures have been compiled.

Optimum: 18~25℃
Range: 8~30℃
Hardiness: Not hardy

Yacon comes from the cool, sunny climate of the mid-altitude Andes, so it grows better in the cool of spring and autumn than in the heat of midsummer. A frost wilts the top growth the same day, but the tubers underground are unharmed, and the crop is dug after that.

In Korea Nationwide

How to grow

Light: Somewhere sunny
Soil and depth: 30cm deep or more
Spacing: 60cm. It gets large
Watering: Do not let it dry in summer
Feeding: Generous base dressing
Harvest: Lift once frost has knocked the leaves down. Leave the tubers a week and they sweeten

What makes the difference. It grows as tall as a person. In a windy spot, stake it

This page describes how a crop is grown and used. It does not claim health effects for any food, nor is it intended to prevent or treat disease. Component and study notes are references only and do not mean the same result occurs in people. Consult a medical professional about health concerns.

Health Benefits

No old record to draw on. Yacon comes from the Andes. It was brought into Korea as a trial crop at a horticultural experiment station in 1985, and cultivation spread among growers from the 1990s. It appears in no old East Asian medical text such as the Donguibogam, so what can be said here reaches only as far as composition analysis and recent research.

Composition - fructooligosaccharides. Composition analysis confirms that much of the yacon root's sweetness comes from fructooligosaccharides, sugars that human digestive enzymes do not break down and that therefore travel intact to the large intestine. That is also why the root carries little energy for how sweet it tastes.

Present-day view - the syrup studies. Human studies have mostly used yacon syrup, the pressed and reduced concentrate of the root, given as a supplement, which is a different thing from peeling and eating the root as food. Results have varied from trial to trial, and pooled analyses have not produced a consistent conclusion. What can be stated for now reaches only as far as the composition.

Present-day view - what happens in the large intestine. That fructooligosaccharides are fermented by gut microbes is established. Being fermentable, though, a large amount at once can leave the belly gassy or loose, so it is worth starting with a small portion.

Nutrition

Fructooligosaccharides (FOS) (Abundant) — A sugar that reaches the large intestine and ferments there
Low calorie, low sugar (Defining trait) — Little energy for how sweet it tastes

Fructooligosaccharides (FOS) & inulin The core component of the yacon root; analyses report it as more than half of the dry weight. Human digestive enzymes do not break it down, so it travels intact to the large intestine, where resident microbes ferment it. That is why the root tastes sweet yet carries little energy.

Sweetness without much energy Yacon tastes strongly sweet, yet much of the sugar behind that sweetness is not absorbed in the small intestine, so the root carries little energy for its bulk and its sweetness. The crisp grain and high water content suit it to being peeled and eaten raw or shredded into a salad.

Chlorogenic acid & caffeic acid Analyses report the antioxidant polyphenols chlorogenic acid and caffeic acid in yacon. The cut surface browning after peeling comes from these phenolic compounds oxidising. This concerns composition only, and nothing has been confirmed in people.

Potassium & dietary fiber Food composition tables confirm potassium and dietary fiber in the root. The portion eaten at one sitting is not large, however, so its share as a nutrient source is modest.

The leaf is not the edible part The part eaten is the underground storage root. Analyses report sesquiterpenoids and flavonoids in the leaves, and Andean tradition includes brewing them as a tea, but whether regular drinking is safe for people has not been established. There is no basis for making leaf tea a daily habit.

Pairings

○ Eaten raw (fresh yacon) — Yacon has a crisp, sweet texture much like an apple, making it perfect to eat as is or to add to salads. It's a root vegetable you can enjoy without cooking, offering a fresh take on an unfamiliar ingredient.

○ Lemon or vinegar — A squeeze of lemon or a splash of vinegar keeps peeled yacon from browning while adding a bright tang. It's a practical pairing that preserves the color of cut yacon and lifts its flavor at the same time.

○ Yogurt and honey — Pairing yacon with yogurt and honey brings prebiotics and probiotics together for a synergistic combination. The FOS in yacon supports the growth of the beneficial bacteria in yogurt, taking the gut-health benefit up a notch.

○ Salad greens — Add yacon slices to lettuce or carrots for a salad with rich, varied texture. Its crunchy bite and natural sweetness round out the plainness of other vegetables.

○ Kimchi and water kimchi — As a Korean twist, more cooks are working yacon into kimchi or mul-kimchi (a mild, brothy 'water kimchi'). The sweetness of yacon meeting the tangy sourness of fermented foods creates a fresh new flavor experience.

△ IBS patients — Yacon's abundant FOS (fructooligosaccharides) can cause gas and bloating in people with irritable bowel syndrome. As a high-FODMAP food, it's best avoided by anyone diagnosed with IBS.

△ Blood-sugar-lowering medication + large amounts — Yacon has a blood-sugar-lowering effect, so patients on glucose-lowering medication risk hypoglycemia if they eat large amounts. It's safest to adjust your intake with medical guidance.

△ Asteraceae (daisy family) allergy — Yacon belongs to the Asteraceae (daisy) family, so anyone allergic to these plants should avoid it. If you react to daisies, ragweed, or chrysanthemums, treat yacon with the same caution.

Varieties

White-fleshed type (Transplant) — The type most often grown in Korean plots. Crisp and juicy, best peeled raw.
Yellow-fleshed type (Transplant) — Flesh has a yellow tinge and a little more sweetness. It browns fast once cut.

Source: Food and Nutrition Information