Family • Discororeaceae - Dioscorea esculenta Lour. - LESSER YAM - Gan shu
|Dioscorea esculenta Lour.|
|Discorea papillaris Blanco|
|Discorea tugui Blanco|
|Discorea sativa Blanco|
|Discorea fasciculata Roxb.|
|Discorea tiliaefolia Kunth|
|Discorea aculeata Naves|
|Oncus esculentus Lour.|
|Gan shu (Chin.)|
|Tugi (Tag., Ilk.)|
|Asiatic yam (Engl.)|
|Chinese yam (Engl.)|
|Lesser yam (Engl.)|
|Tian shu (Chin.)|
Other vernacular names
|CHINESE: Ci shu yu, You ci gan shu.|
|FRENCH: Igname De Chine épineuse, Igname Des Blancs.|
|GERMAN: Chinesischer yam.|
|PORTUGUESE: Inhame, Inhame-De-São.|
|SPANISH: Batata de China.|
|TAMIL: Siruvalli kilangu.|
|TELUGU: Tippa Tiga.|
Tugi is a slender, slightly hairy, spiny vine, reaching a height of several meters. Tubers are 15 to 20 centimeters long, except in the case of some cultivated forms. Leaves are simple, suborbicular to reniform, 6 to 12 centimeters long, apiculate, the base 11- to 15-nerved, prominently heart-shaped, with rounded lobes. Spikes are slender, axillary, pubescent, up to 50 centimeters long. Flowers are green, about 4 millimeters in diameter.
Additional Sources and Suggested Readings
(1) Local Root Crops as Antioxidants / Innovations Report
(2) Starch and sugar conversion in Dioscorea esculenta tubers and Curcuma longa rhizomes during storage / R Panneerselvam and C Abdul Jaleel / Caspian J. Env. Sci. 2008, Vol. 6 No. 2 pp. 151~160
(3) In vitro antioxidant studies of Dioscorea esculenta (Lour). Burkill / Manickam Murugan, Veerabahu Ramasamy Mohan* / Asian Pacific Journal of Tropical Biomedicine (2012)S1620-S1624
(4) Antifertility acitivity of ethanol extract of Dioscorea esculenta (L.) Schott on male albino rats. / P.S. Shajeela, V.R.Mohan*, L. Louis Jesudas and P.Tresina Soris / International Journal of PharmTech Research, Vol. 3, No.2, pp 946-954, April-June 2011
– In thickets and secondary forests at low altitudes in Bataan Islands, in Cagayan, Benguet, La Union, Pangasinan in Luzon, and in Semirara.
– Also cultivated, but not as extensively as ubi (Dioscorea alata).
– Also occurs in China, India to Malaya and Polynesia.
– Contains 83% starch, 12% protein.
– Tubers are a good source of vitamin B.
– Phytochemical screening yielded saponins, diosgenin, ß-sitosterol, stigmasterol, cardiac glycosides, fat and starch.
– Edible yams have yield polyphenolic substances such as catechins, epicatechins, chlorogenic acids, leucoanthocyanidins and anthocyanins.
Edibility / Nutritional
– Cooked like potatoes.
– Rich in carbohydrates, a good source of vitamin B, with a nutritional value similar to ubi.
– The raw tubers are applied to swellings.
– In Indo-China, decoction of the tubers used for rheumatism and as diuretic.
– In China, used for beriberi.
– Tuber paste applied to ulcers, boils, abscesses.
– Used in the treatment of menopausal symptoms and other genital organ disorders.
• Anti-inflammatory / Phytochemicals: Methanol extract study of D esculenta exhibited significant dose-dependent inhibition of carrageenan-induced edema and supports its folkloric use in inflammation. Phytochemical screening yielded saponins, diosgenin, ß-sitosterol, stigmasterol, cardiac glycosides, fat and starch.
• Antioxidant: Study screening the phenolic content of different varieties of root crops in the Philippines, including D esculenta, found the roots crops a rich source of phenolic compounds with antioxidant activity.
• Storage Effect: Study of 1 to 7 weeks of storage revealed the moisture content, dray weight and starch levels decreased gradually with a concomitant increase in sugar content under different stages of dormancy.
• Antioxidant / Phenolic Content: Study of a methanolic extract showed a total phenolic content of 0.7 g/110g. Results confirmed potential in vitro antioxidant activity, which was attributed to phenols and flavonoids.
• Inulin: Study showed the production of inulin powder from lesser yam through the foam mat drying method using maltodextrin and egg white as filler and foaming agent. Inulin is a natural nondigestible fructooligosaccharide that occurs as reserve carbohydrate in several plants. Higher amounts of inulin could be extracted from D. esculenta compared to other tubers.
• Antifertility Activity: Study investigated the antifertility effect of an ethanol extract in male albino rats. Results showed antifertility effects by inhibition of sperm concentration, motility, and testosterone.