Dietary fiber or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition and can be grouped generally by their solubility, viscosity and fermentability which affect how fibers are processed in the body. Dietary fiber has two main subtypes: soluble fiber and insoluble fiber which are components of plant-based foods such as legumes, whole grains, cereals, vegetables, fruits, and nuts or seeds. A diet high in regular fiber consumption is generally associated with supporting health and lowering the risk of several diseases. Dietary fiber consists of non-starch polysaccharides and other plant components such as cellulose, resistant starch, resistant dextrins, inulins, lignins, chitins, pectins, beta-glucans, and oligosaccharides.
Root vegetables are underground plant parts eaten by humans or animals as food. In agricultural and culinary terminology, the term applies to true roots such as taproots and tuberous roots as well as non-roots such as bulbs, corms, rhizomes, and stem tubers.
Dioscorea alata – also called ube, ubi, purple yam, or greater yam, among many other names – is a species of yam. The tubers are usually a vivid violet-purple to bright lavender in color, but some range in color from cream to plain white. It is sometimes confused with taro and the Okinawa sweet potato beniimo (紅芋), however D. alata is also grown in Okinawa. With its origins in the Asian and Oceanian tropics, D. alata has been known to humans since ancient times.
Amorphophallus konjac –also known as konnyaku, and konjac– is a vegetable species native to Yunnan in southwest China which has an edible corm. It is also known as devil's tongue, voodoo lily, snake palm, or elephant yam. It is a relative of the titan arum, one of the largest flowering plants in the world and a congener of konjac.
Taro is a root vegetable. It is the most widely cultivated species of several plants in the family Araceae that are used as vegetables for their corms, leaves, stems and petioles. Taro corms are a food staple in African, Oceanic, East Asian, Southeast Asian and South Asian cultures. Taro is believed to be one of the earliest cultivated plants.
Dioscorea communis or Tamus communis is a species of flowering plant in the yam family Dioscoreaceae and is commonly known as black bryony, lady's-seal or black bindweed.
Yam is the common name for some plant species in the genus Dioscorea that form edible tubers.
Dioscorea polystachya or Chinese yam, also called cinnamon-vine, is a species of flowering plant in the yam family. It is sometimes called Chinese potato or by its Korean name ma. It is also called huaishan in Mandarin and wàaih sāan in Cantonese.
Dioscorea bulbifera is a species of true yam in the yam family, Dioscoreaceae. It is native to Africa, Asia and northern Australia. It is widely cultivated and has become naturalized in many regions.
Amorphophallus paeoniifolius, the elephant foot yam or whitespot giant arum, is a tropical plant native to Island Southeast Asia. It is cultivated for its edible tubers in Southeast Asia, South Asia, Madagascar, New Guinea, and the Pacific islands. Because of its production potential and popularity as a vegetable in various cuisines, it can be raised as a cash crop.
Dioscorea esculenta, commonly known as the lesser yam, is a yam species native to Island Southeast Asia and introduced to Near Oceania and East Africa by early Austronesian voyagers. It is grown for their edible tubers, though it has smaller tubers than the more widely-cultivated Dioscorea alata and is usually spiny.
Dioscorea trifida is a species of flowering plant in the family Dioscoreaceae. It is a species of yam. It is native to the Caribbean and Central and South America. Its many common names include Indian yam, cush-cush, and yampee. It is called mapuey in Venezuela, inhame in Brazil, tabena and ñame in Colombia, sacha papa in Peru, and ñampi in Costa Rica.
Tacca leontopetaloides is a species of flowering plant in the yam family Dioscoreaceae. It is native to the islands of Southeast Asia. Austronesian peoples introduced it as a canoe plant throughout the Indo-Pacific tropics during prehistoric times. It has become naturalized to tropical Africa, South Asia, northern Australia, and Oceania. Common names include Polynesian arrowroot, Fiji arrowroot, East Indies arrowroot, pia, and seashore bat lily.
Nigeria is by far the world’s largest producer of yams, accounting for over 70–76 percent of the world production. According to the Food and Agriculture Organization report, in 1985, Nigeria produced 18.3 million tonnes of yam from 1.5 million hectares, representing 73.8 percent of total yam production in Africa. According to 2008 figures, yam production in Nigeria has nearly doubled since 1985, with Nigeria producing 35.017 million metric tonnes with value equivalent of US$5.654 billion. In perspective, the world's second and third largest producers of yams, Côte d'Ivoire and Ghana, only produced 6.9 and 4.8 million tonnes of yams in 2008 respectively. According to the International Institute of Tropical Agriculture, Nigeria accounted for about 70 percent of the world production amounting to 17 million tonnes from land area 2,837,000 hectares under yam cultivation.
Dioscorea pentaphylla is a species of flowering plant in the yam family known by the common name fiveleaf yam. It is native to southern and eastern Asia as well as New Guinea, Sri Lanka and northern Australia. It is widely cultivated as a food crop and naturalized in Cuba and on several island chains in the Pacific.
Dioscorine is an alkaloid toxin isolated from the tubers of tropical yam on several continents. It has been used as a monkey poison in some African countries, and as an arrow poison to aid in hunting in several parts of Asia. It was first isolated from Dioscorea hirsute by Boorsma in 1894 and obtained in a crystalline form by Schutte in 1897, and has since been found in other Dioscorea species. Dioscorine is a neurotoxin that acts by blocking the nicotinic acetylcholine receptor. Dioscorine is generally isolated in tandem with other alkaloids such as dioscin but is usually the most potent toxin in the mixture. It is a convulsant, producing symptoms similar to picrotoxin, with which it shares a similar mechanism of action.
Kripik or keripik are Indonesian chips or crisps, bite-size snack crackers that can be savoury or sweet. They are made from various dried fruits, tubers, vegetables, and fish that have undergone a deep frying process in hot vegetable oil. They can be lightly seasoned with salt, or spiced with chili powder and sugar.
Dioscorea dumetorum, also known as the bitter yam, cluster yam, trifoliate yam, or three-leaved yam, is a species of flowering plant in the yam family, Dioscorea. It is native to sub-Saharan Africa and especially common in the tropical regions of West Africa, including Nigeria, Benin, and Ghana. D. dumetorum has both toxic and non-toxic varieties.
One of the major human migration events was the maritime settlement of the islands of the Indo-Pacific by the Austronesian peoples, believed to have started from at least 5,500 to 4,000 BP. These migrations were accompanied by a set of domesticated, semi-domesticated, and commensal plants and animals transported via outrigger ships and catamarans that enabled early Austronesians to thrive in the islands of Maritime Southeast Asia, Near Oceania (Melanesia), Remote Oceania, Madagascar, and the Comoros Islands.
Dioscorea deltoidea, the Nepal yam, is a species of flowering plant in the family Dioscoreaceae. Its native range is the Himalayas through to south-central China and mainland Southeast Asia. Its tubers contain diosgenin and are harvested by local peoples as a treatment for a variety of conditions, including gastrointestinal disorders and intestinal worms. Tubers are also eaten after boiling, washing, and baking. It grows in forests and humus-rich soils.
