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.
- 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%
- 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.
- Traditionally uses suggest anti-inflammatory, anti-stress, anti-spasmodic properties.
Edibility / Nutritional
- Cooked like potatoes.
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.