Yacon: Smallanthus sonchifolius
- Kami Kenna
- Jan 16
- 3 min read
Taxonomically, yacon pertains to the Asteraceae family (the sunflower family), the same family as chicory, Jerusalem artichokes, and dahlias (Manrique et al., 3). Smallanthus sonchifolius is a genus comprising 21 species. “The storage organ of all of these species accumulates a type of fructan known as inulin, which is similar to FOS [fructooligosaccharides] except at a high degree of polymerization” (Manrique et al., 5). Yacon is the plant source with the largest known content of FOS.
A relative of the sunchoke (topinambur), a tuber native to North America, yacon is the South American counterpart native to the Andes. It is cultivated in Amazonas, Cajamarca, San Martín, Pasco, Puno, Cuzco, and Apurímac in Perú, as well as in Bolivia, Colombia, and Venezuela, growing across elevations from 800 to 2,800 meters.
It is eaten fresh, like a pear or an apple; more like a fruit than other tubers, it is sold alongside chirimoya in markets rather than with potatoes and other tubers. When consumed fresh, yacon is first left to dry in the sun for as many as ten days to concentrate its natural sweetness. “Studies have demonstrated that soon after harvesting, a rapid transformation of the composition of the sugars occurs: the FOS are hydrolyzed by an enzyme called fructan hydrolase into simple sugars (i.e., fructose, glucose, and sucrose). After a week of storage at room temperature, approximately 30–40% of the FOS will have transformed into simple sugars” (Graefe et al., 2004; Manrique et al., 7).
Another popular use is making a syrup from fresh yacon juice, which can serve as an alternative to sugar. Its high inulin content makes yacon suitable for diabetics and provides significant prebiotics. “Yacon syrup can also be consumed (in moderation) by diabetics, as the consumption of FOS does not increase the amount of glucose in the blood” (Manrique et al., 5).
FOS explained: “...chemically composed of 1 molecule of glucose connected to between 2 and 10 fructose molecules. The bonds that connect the molecules of fructose are able to resist the hydrolysis of enzymes in the human digestive system and are therefore able to reach the colon without being broken down and digested by the body. It is for this reason that FOS have a low caloric value for humans (25–30% of the calories possessed by other sugars)” (Manrique et al., 5).
In Japan, Brazil, and Peru, the leaves have been used as an infusion or tea, thought to lower blood glucose levels in people with diabetes.
Yacon is a perennial plant that grows in bunches of 4 to 20 fibrous tubers that can be white, orange, or purple. It thrives at higher altitudes between 1,500 and 2,000 meters, where hot days give way to cool nights. In the high jungles of the Andes, it can be cultivated year-round. Here’s looking at you, Cocachimba, located at 1800 meters, this an ideal growing region for yacon.
The initial sugar concentration in the root ranges from 8–12º Brix (Manrique et al., 9). FOS are only affected by temperatures above 120ºC, at which point the sugars begin to break down into simpler forms (L’homme et al., 2003), which are required for fermentation. “The simple sugars found in yacon (sucrose, fructose, and glucose) are four times sweeter than FOS. This means that if the roots taste less sweet, there is a greater probability that they have a high content of FOS (Manrique et al., 11).
“In preliminary tests conducted at the International Potato Center (CIP), it was found that the skin could easily be removed after being exposed to high-pressure steam in a domestic pressure cooker. The skin is released in a clean fashion, without wastage of the flesh, resulting in a significant saving of raw material in comparison with conventional peeling methods” (Manrique et al., 14). Based on this, I used a pressure cooker at 120ºC to break down FOS and significantly facilitate the peeling of the skin.
Read “Distilling Yacon” for how I processed the yacon for distillation at the Pirqapata lab during my residency in December 2025.
Works Cited
Manrique, I.; A. Párraga, and M. Hermann 2005. Yacon syrup: Principles and processing. Series: Conservación y uso de la biodiversidad de raíces y tubérculos andinos: Una década de investigación para el desarrollo (1993-2003). No. 8B. International Potato Center, Universidad Nacional Daniel Alcides Carrión, Erbacher Foundation, Swiss Agency for Development and Cooperation. Lima, Peru. 31
Works Consulted
BLANCKE, ROLF. “Tubers.” Tropical Fruits and Other Edible Plants of the World: An Illustrated Guide, Cornell University Press, 2016, pp. 258–74. JSTOR, http://www.jstor.org/stable/10.7591/j.ctvrf8b9w.6. Accessed 9 Dec. 2025.
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