A member of the sunflower
family, native to the lower Peruvian Andes and many many South American
forest regions, and long valued as a root crop. It was first recorded
as a native cultivated root crop by the Andeans in 1615. Fresh tubers
are crisp and juicy redolent of apples and melons, sometimes referred
to as "Apple of the Earth." It has a sweetness that increases
with storage. Eaten raw, baked, roasted, jammed, juiced into syrup or
drinks, or made into pudding dishes.
Yacon is a perennial herb growing
to a height of 2 to 3 meters. Leaves are broadly ovate with widely toothed
margins and extending into the stems. Flowers are daisy-like, yellow to orange,
avidly pollinated by insects. Root crop is edible, fleshy, yellowish white,
sweet, with a crisp consistency of sinkamas.
- Recently introduced and
cultivated in the Mountain Province area.
- Originally cultivated in the Andean highlights.
- Reported in China and Japan.
• The root or tuber is a rich source of fructo-oligosaccharides
(FOS), 'prebiotics' responsible for the sweet flavor while poorly metabolized
or digested, a characteristic for a potential low calorie sweetener.
• Probiotic and antioxidant properties from protocatechuic, chlorogenic,
caffeic and ferulic acids found in the leaves.
• Inulin may be responsible for its effect on blood sugar.
• Leaves yield monoterpenes, sesquiterpenes, and diterpenes.
• Tubers yield a high content of oligofructans and polyphenols.
• Other chemicals documented in yacon include: y-cadinene, caffeic-acid,
3-caffeoylquinic-acid, chlorogenic-acid, 2,4-dicaffeoylaltraric-acid,
2,5-dicaffeoylaltraric-acid, 3,5-dicaffeoylaltraric-acid, 3,5-dicaffeoylquinic-acid,
enhydrin, ferulic-acid, fluctuanin, gallic-acid, gentisic-acid, inulin,
melampolides, oligofructans, beta-pinene, protocatechuic-acid, rosmarinic-acid,
sonchifolin, tryptophan, 2,3,5-tricaffeoylaltraric-acid, 2,4,5-tricaffeoylaltraric-acid,
• Chloroform fraction of alcohol extract of leaves yielded seven compounds: gallic acid (1), beta-sitosterol (2), behenic acid (3), kaempferol (4), quercetin (5), vanillic acid (6), hexadecanoic acid (7). (12)
• Major portion of tuberous root biomass is water (>70% of fresh weight), saccharides, especially oligofructans (70-80% of dry weight), protein content (0.3% to 3.7%). (23)
• Mean tuberous root composition per 100 g of fresh matter is: water 81.3, saccharides 13.8, fiber 0.9, proteins 1.0, lipids 0.1, and ash 1.1. (23)
• Mean mineral content per 100 g of fresh matter are: potassium 334, phosphorus 34, calcium 12, magnesium 8.4, sodium 0.4 and iron 0.2. Vitamins B1, B2, C, β-carotene and polyphenols in the same weight are present at mean concentrations 0.07, 0.31, 5.0, 0.13 and 203 mg, respectively. (23)
• Leaves yield di- and sesquiterpenes, polyphenolic antioxidants, esp. hydroxycinnamic acids and chlorogenic acid; a new antifungal melampolide – sesquiterpene lactone named sonchifolin, as well as three known melampolides, polymatin B, uvedalin and enhydrin. (23)
• Study of free amino acid composition of roots of yacon cultivars ranged from 147.9 to 341.1 mg/q00 g. The main free amino acids in all cultivars were arginine and glutamine. Proline content varies from 1.1 to 97.4 mg/100 g. Freeze-dried yacon powder yielded total free amino acids of 1941.2 mg/100 g, glutamine 212.4 mg/100g, and arginine 994.1 mg/100 g. (38)
• Nutritional proximate analysis of a 100-gram sample of freeze-dried yacon tuber yielded low levels of protein (2.43 g), moderate fiber (4.47 g) and high level of carbohydrate (73.8 g). A 100-gram sample of dried leaves yielded high protein levels (15.24 g), and fiber (5.67 g) and moderate level of lipids (2.81 g). Potassium comprised more than 50% of total mineral content of leaves and tuber. Phytochemical screening yielded phenolics, alkaloids, sesquiterpene lactones, terpenoids and triterpenoids. (see study below) (44)
• Total phenolic content of tuber and leaf extracts (mg GAE/100 g and mg QE/100 g were: tuber methanolic extract (164.2 ± 16.9 and 167.5 ± 15.0), leaf decoction extract (3,489.4 ± 129.9 and 3,484.7 ±142.1) and leaf methanol extract (529.2 ± 52.4 and 214.8 ± 46.1). (see study below) (44)
• Study of leaves yielded three novel compounds viz., ent-kaurane-3β,16β,17,18-tertol, 3R,7E-9-butoxyl-megastigma-3-ol-3-O-β-d-glucopyranoside, and 3S,5R,6Z-megastigma-6-en-3,5,8,9-tertol, together with five known ingredients: octacosanol (1), 3′,4′,5-trihydroxy-3,7-dimethoxyflavone (2), 3,4-dihydroxybenzaldehyde (3), isorhamnetin (4), and ent-kaurane-3β,16β,17-triol (5). (45)
• Studies have suggested antioxidant, cytoprotective, antidiabetic, prebiotic, antimicrobial, hepatoprotective, trypanocidal, antiteratogenic, anti-inflammatory, hypolipidemic, immunomodulatory properties.
Leaves and tubers.
Edibility / Nutrition
- Fresh tubers are crisp and juicy when eaten raw; sweetness increases with storage.
- Tubers also steamed, baked, or roasted. Also, processed into jams, juice, cereals, etc. (2)
- In Japan and Brazil, aerial parts used as components of
medicinal tea. (See caution below) (25)
- Rich in potassium, calcium, and phosphorus.
- Decoction of leaves used
as tea for diabetics.
- In South America, the raw tubers as a diuretic
for kidney and bladder problems.
- In Bolivia, decoction of leaves used for cystitis,
hepatosis and nephrosis.
- In Peru, warm poultice of leaves used for
myalgias and rheumatism.
- In Brazil, leaves decocted for diabetes.
• Local Root Crops as Antioxidant:
A 2006 study of commonly consumed roots crops in the Philippines (Kamote,
ubi, purple yam, Dioscorea alata; cassava, Manihot esculenta;
taro or gabi, Colocasia esculenta; carrot, Daucus carota; yacon (Smallanthus
sonchifolius) showed them to be rich sources of phenolic compounds with
antioxidant activity, highest in sweet potato, followed by taro, potato,
purple yam and lowest in the carrot. (1)
Acid / Antioxidant:
A study of the crude extracts of dried leaves and tubers of yacon
yielded phenolic acids – chlorogenic, caffeic and ferulic acids
– contributing to the radical scavenging activity detected. (4)
/ Anti-hyperglycemic: Report suggests the
anti-hyperglycemic activity of tubers and cytoprotective activity of
its leaves are probably due to the oligofructan and phenolic content,
Inulin and oligofructose from the extracts of
yacon roots known for its prebiotic properties presents a potential
use in treating certain types of colitis by stimulating growth of Lactobacillus
and Bifidogacterium microflora. (6)
/ Colonic Transit Time: Yacon syrup's
effect on colon-transit time was studied in healthy volunteers. Results
showed an softer stools and acceleration of colonic transit time. Transit time through the gastrointestinal tract was significant decreased from 59.7 ± 4.3 to 38.4 ± 4.2 h (p<0.001). It was well tolerated with an excellent side effect profile. With
its low caloric content, it presents a potential treatment of
constipation in the obese and diabetic. (8)
• Subchronic Toxicity Studies: A 4-month oral consumption of dried yacon root flour and diet supplement on normal Wistar rats showed to be well tolerated with no negative responses, toxicity, or adverse nutritional effects. It showed significantly reduced serum triglyceride levels. (9)
• Antioxidant / Cytoprotective/ Antihyperglycemic: All extracts exhibited strong protective activity against oxidative damage to rat hepatocyte cultures, reduced hepatic glucose production via gluconeogenesis and glycogenolysis. The combination of radical scavenging, cytoprotective and antihyperglycemic activities presents a potential use in the prevention and treatment of chronic diseases involving oxidative stress, especially diabetes.
• Antibacterial: Study showed the enhancement and antimicrobial activity of yacon leaves against methicillin-resistant Staphylococcus aureus in the presence of light. (10)
• Antiteratogenic Potential: Extracts from the leaf of P. laevigata and yacon tubers (Smallanthus sonchifolius) were studied for antiteratogenic potential using duck embryos. Extracts administered with retinoic acid had antiteratogenic properties. (11)
• Antidiabetic / Alpha-Glucosidase Inhibition: Study evaluated the inhibitory effect of smallanthaditerpenic acids A, B, C and D on alpha-glucosidases. Their IC50 were determined to be 0.48 mg/mL, 0.59 mg/mL, 1.00 mg/mL, and 1.17 mg/mL respectively. (13)
• Antidiabetic / Tubers: Study evaluated the hypoglycemic effect of yacon tubers on alloxan-induced diabetes in mice. Results showed yacon significantly reduced blood sugar level. (14)
• Decreased Hepatic Insulin Resistance: Study evaluated the effect of a yacon diet on blood glucose. Results showed reduction of blood glucose likely due to its beneficial effects on hepatic insulin sensitivity in the insulin resistance state. (16)
• Yacon FOS (Fructo-Oligosaccharides) / Prebiotic: Study have shown the benefits of prebiotics like inulin and FOS in health and nutrition. This study showed yacon can prevent enteric infection caused by S. typhimurium, the effect mediated by enhancing non-specific immunity, such as total S-IgA, that improves the immunological intestinal barrier. (17)
• Antibacterial Activity of Leaf Constituents / Enhydrin: Study investigated the antibacterial activity of leaf constituents enhydrin, polymatin B, alloschkuhriolide. Results showed only enhydrin showed antibacterial activity against MRSA (methicillin resistant Staphylococcus aureus). (18)
• Yacon Fructans Effect on Maintenance of Healthy Bones: Yacon flour consumption significantly resulted in a positive Ca and Mg balance leading to higher bone mineral retention and biomechanical properties. The positive effects on mineral intestinal absorption, bone mass, and biomechanical properties showed yacon's important role in the maintenance of healthy bones. (19)
• Trypanocidal / Chagas Disease: Study isolated sesquiterpene lactones enhydrin, uvedalin, and polymatin B from an organic extract of S. sonchifolius. The compounds were tested for trypanocidal activity against Trypanosoma cruzi. Results suggest enhydrin and uvedalin might have potential as agents against Chagas disease. (20)
• Antioxidant / Leaves: Study evaluated various extracts of leaves for antioxidant activity and phenolic content. Study yielded protocatechuic, chlorogenic, caffeic and ferulic acids from two fractions. Both fractions showed potent antioxidant activity in the DPPH and xanthine/XOD superoxide radical scavenging tests. Results suggest the use of leaves in human diet may be a potential remedy for the prevention of chronic diseases cause by radicals, e.g., arteriosclerosis. (21)
• Constituents and Activities: Study evaluated the botany, composition, and main constituents of Smallanthus sonchifolius (yacon) and Lepidium meyeni (maca). The potential of yacon tubers to treat hyperglycemia, kidney problems and skin rejuvenation and the antihyperglycemic and cytoprotective activity of leaves seem mostly related to its oligofructan and phenolic content. (22)
• Glycemic Effect in Diabetic Rats: Study of crude extracts of leaves showed on STZ induced glycemia in rats showed the effectiveness of yacon extracts is related to the method of preparation and time of treatment. The hydroalcoholic extract significantly reduced the levels of glucose in the diabetic rats. (24)
• Caution / Renal Toxicity Report / Leaves: Study evaluated the repeated-dose toxicity of three extracts of yacon leaves. Results showed renal damage associated with increased blood glucose levels after prolonged oral administration of aqueous extract. Evidence suggests the terpenoids were the main toxic compounds. Based on the results, the oral use of yacon leaves is not recommended to treat diabetes. (25)
• Effect of Hepatic Metabolism: Study of extracts and fractions of leaves extracts showed strong protective effect against oxidative damage to rat hepatocyte cultures, reduced glucose production via gluconeogenesis and glycogenolysis. The combination of radical scavenging, cytoprotective and anti-hyperglycemic activity of leaves suggest potential for use in prevention and treatment of chronic diseases involving oxidative stress, particularly diabetes. (26)
• Prebiotic Effect on Intestinal Mucosa / Yacon Root Flour: Study evaluated the prebiotic property of yacon root flour and its influence on the intestinal microbiota and gut immune system using a mice model. Results showed long term administration of yacon root flour maintained the intestinal homeostasis without inflammatory effect regulated through IL-10 and IL-4 regulatory cytokines. (27)
• Protective Effect / Colon Carcinogenesis: Study investigated the potential benefit of yacon intake on colon carcinogenesis induced by DMH in male Wistar rats. Results showed a significant reduction in number of aberrant crypt foci and number of invasive adenocarcinomas. Results suggest dried extract of yacon root or a symbiotic formulation of yacon plus Lactobacillus casei intake may reduce the development of chemically-induced colon cancer. Study suggests yacon root intake may have a potential as chemopreventive agent against colon carcinogenesis. (28)
• Topical Anti-Inflammatory / Effect on Neutrophil Migration: Study evaluated the in vivo topical anti-inflammatory potential of a leaf-rinse extract from dried leaves of yacon on croton oil ear edema assay in mice. Results showed topical anti-inflammatory effect with anti-oedematogenic activity followed by inhibition of neutrophil migration. (29)
• Colonic Health Maintenance: Study in rats showed consuming 10% yacon tuber powder and cookies containing 14.75% yacon tuber (equivalent to 5% and 9.5% of FOS, respectively) for 28 days resulted in changes in bowel habit, cecum size, SCFAs production and intestinal microbial community significantly different from consumption of commercialized FOS and placebo cookies. Results suggests yacon tuber consumption may play an important and slightly different role in colonic health. (31)
• Improved Antioxidant Activity: Study evaluated the effects of different forms of yacon extracts on the lipid oxidation and color of emulsion-type sausage. Study reported significant decrease in pH and residual nitrite values, increased thiobarbituric and reactive substances. Results suggest the addition of 20% yacon extract to emulsion-type sausages was most effective in improving lipid oxidative stability. (32)
• Comparative Hypoglycemic Activity of Yacon and Stevia: Study evaluated ethanolic leaf extracts of Yacon and Stevia for hypoglycemic action in streptozotocin induced diabetic mice. Results showed Stevia rebaudiana exhibited hypoglycemic activity comparable to the drug metformin while the leaf extract of Smallanthus sonchifolius showed no hypoglycemic action. (33)
• Hypoglycemic / Hypolipidemic / Tuber Extract and Chlorogenic Acid Constituent: Study evaluated the hypoglycemic effect of Yacon tuber extract and its constituent, chlorogenic acid (CGA), in streptozotocin induced diabetic rats. Results showed a significant hypoglycemic effect, together with significant decreases in total cholesterol and triglycerides. Radical scavenging activity of CGA was similar to vitamin E control. Results suggest a potential in the management of hyperglycemia and diabetic nephropathy. (34)
• Hypolipidemic / Roots: Frutooligosaccharides (FOS) are sugars naturally found at high concentrations in storage roots of yacon. Study evaluated the effects of subchronic oral consumption of yacon root flour as diet supplement in STZ-induced diabetic Wistar rats. The FOS-rich yacon flour did not significantly alter the weight of test animals. There was a significant decrease in fasting plasma triacylglycerol and VLDL. An identified incretin could be an effective mediator of the lipid lowering effects of FOS present in the yacon flour. Results suggest yacon root flour, a natural product rich in FOS, has potential as a nutraceutical product with beneficial effects in diabetes-associated hyperlipidemia. (36)
• Caffeic Acid / Roots: Study of a phenolic fraction of yacon roots yielded major water-soluble phenolic compounds: two of these were chlorogenic acid (3-caffeoylquinic acid) and 3,5-dicaffeoylquinic acid; three were novel caffeic acid esters of altraric acid, viz. 2,4- or 3,5-dicaffeoylaltraric acid, 2,5-dicaffeoylaltraric acid, and 2,3,5- or 2,4,5- tricaffeoylaltraric acid. (35)
• Effect of Aging on Fermented Yacon and Sensory Profile: Perishability and low production volume is a problem. Study analyzed the changes in aging during one year of storage and sensory analysis of fermented yacon. At the end of the one-year aging, total and volatile acidity increased significantly (p<0.05), together with a decrease in FOS (fructooligosaccharide). The product showed good antioxidant capacity with acceptable sensory profiles. Results suggest alternatives in the industrial sector and potential for farmers to do large-scale production. (37)
• Effect on Pancreatic Fibrosis: Study in rats suggests 1% yacon extract has an inhibitory effect on DBTC-induced pancreatic fibrosis. (39)
• Prebiotic and Immunomodulatory Effect: Yacon tubers contain frutooligosaccharidges (FOS), known as prebiotics, beneficial in improving the host's intestinal flora balance and enhance immunomodulatory potential. This study investigated the effect of FOS-rich yacon extract on intestinal flora and immune system of BABL/c mice sensitized and challenged with ovalbumin. Study showed improvement in intestinal flora. Results suggest yacon-derived FOS can epidemiologically improve Th1/Th2 cytokine balance through its prebiotic effect on the number of beneficial bacterial in the animal gut. (40)
• Effect in an Intestinal Infection Model of Salmonella typhimurium: Study analyzed the preventive effects of yacon on enteric infection caused by a strain of Salmonella enteritidis serovar typhimurium in a mouse model. Results suggest yacon can prevent enteric S. typhimurium infection given up to 30 days, mediated by enhancing non-specific immunity such as total S-IgA which improved the immunological intestinal barrier. (41)
• Comparative Antioxidant Effect of Leaves and Roots: Study compared the in vivo hepatic antioxidant activity of hydroalcoholic extracts of yacon leaves and roots in rats with STZ-induced diabetes in terms of in vitro antioxidant capacity. Both roots and leaves extract restored the increased protein carbonyl levels to normality, while the roots extract restored ROS levels to normality. The in vivo action of the root extract was more effective than the leaf extract in reducing hepatic oxidative stress that accompanies diabetes. (42)
• Invention / Buccal Tablet Formulation: An invention reports on the use of dried power of Smallanthus sonchifolius as the main drug component in buccal tablet formulation, as well as fermented S. sonchifolius leaves, chrysanthemum and liquorice extracts as adjuvant components together with auxillary ingredients. The resulting buccal tablet has the characteristic of diminishing inflammation, inhibiting bacteria, as well as a pleasant mouthfeel and easy absorption property. (43)
• Bioactivities of Phenolic Compounds / Antioxidant: Phenolic extracts were found to have significant DPPH radical scavenging activity and significant anti-lipoperoxidativve activity on rat liver microsomes comparable to commercial supplement containing silymarin. On CAM vascular irritation assay, the phenolic extract exhibited an anti-inflammatory activity comparable to hydrocortisone. (see constituents above) (44)
- Although the roots
and tubers are popular marketed for its diabetic benefits, many studies report the hypoglycemic
or sugar-lowering effect only in the leaves.
- Commercial herbal tea leaves.
- Root and leaf extracts in the cybermarket.