Chinese water chestnut or water chestnut scientifically known as Eleocharis dulcis is an edible tuber that belongs to the sedge family of Cyperaceae and is native to Asia (China, Japan, India, Philippines, etc.), Australia, tropical Africa, and various islands of the Pacific and Indian Oceans. It is grown in many countries for its edible corms. Chinese water chestnut may be mistaken for the European type (Trapa natans) and another Chinese water chestnut (Trapa bicornis) which have dense floating leaves and produce a horn-shaped nut. These are not economically important and can become weeds. Bush Nut, Chinese water chestnut, Edible Spike Rush, Ground Chestnut, Spike Rush, Water Chestnut and Water Nut are some of the popular common names of Chinese Water chestnuts. Water chestnut is not a nut at all, but an aquatic vegetable that grows in marshes, underwater, in the mud and has a delicate taste and a crunchy texture that makes it ideal in stir-fried and sautéed vegetable dishes or simply raw in a salad.
Plant
Water chestnuts are leafless, tuberous, rush-like, and marginal aquatic perennial vegetable found growing in mud in margins of Shallow lakes, ponds, paddy fields, swamps and marshes and prefers sunny locations and normally grows well in rich, friable soil, well manure or fertilized in shallow water. Chestnuts are grown in water and are often rotated with the rice crop. Plants grow from 50 to 200 cm tall and stem is erect, terete, tufted, 40-200 cm tall, 3-10 mm in diameter, longitudinally striate, distinctly transversely septate, the intersepta 5-12 mm long, hollow, smooth, greyish to glossy dark green colored. They produce many flowers which are very small and occur on the tips of the culms. Flowers are generally produced before the plant reaches its height of vegetative growth. The plants have elongated stolons with a tuber attached to it at its bottom. Due to the absence of leaves, photosynthesis in the plants is carried out by the culms or stems.
Fruit
Water chestnut is a tuberous, aquatic perennial vegetable most likely grown for its edible, dark brown tubers (corms) than it is grown for ornamental purposes. Water chestnut is not a nut at all, but an aquatic vegetable that grows in marshes, underwater, in the mud. Water chestnut is a small, round gladiola bulbs vegetable about 2-4 cm in diameter that has a thin brown skin and a crunchy, juicy, sweet and fragrant white flesh. It has a fresh, delicate taste and mild flavor like a blend between apple, chestnut and coconut and crunchy texture ideal for stir-fried and sautéed vegetable dishes or simply raw in a salad. It holds an important place in Oriental cuisines. Because of its amazing taste Chinese water chestnut is a popular ingredient in Chinese and Southeast Asian cuisines as well.
History
Water Chestnut plant is indigenous to the old world tropics- tropical West Africa and Madagascar to southern Asia, Indian Ocean Islands, south-east Asia, southern China, Taiwan and Japan, Melesia, northern Australia and eastward to the Pacific in Melanesia and Micronesia. At present it is grown in throughout the world because of its edible corms.
Nutritional Value
Apart from their fresh, delicate taste and mild flavor, water chestnut is a good source of nutrients, vitamins and minerals. Consuming 124 gram of water chestnuts offers 0.404 mg of Copper, 0.407 mg of Vitamin B6, 29.69 g of Carbohydrate, 0.248 mg of Vitamin B2, 0.41 mg of Manganese, 724 mg of Potassium, 0.174 mg of Vitamin B1 and 0.594 mg of Vitamin B5.
It has sweet mild flavor and crunchy texture. Due to high nutrition content, it becomes an excellent food source. Due to its medicinal properties it is used in Ayurvedic medicines. The health benefits of water chestnuts are discussed below:
1. Proper Growth
Water chestnuts contains sufficient amount of Copper which is vital for normal growth and health. Thus, it is very important to include this mineral in balanced levels in your regular diets. It is supportive in the protection of the skeletal, cardiovascular and nervous systems. Normal and healthy growth of organs and tissues, as well as their proper oxygenation from an ample red blood cell concentration, would be impossible if your body is lacking copper. A copper deficiency is seen in many countries, and is reflected in the number of birth and growth defects in children of those nations.
2. Protects Eye Health
Poor diet or nutrient deficiencies are actually fundamental reasons of countless eye diseases. Research has shown that that taking vitamin B6 along with other vitamins, like folate, can help with the prevention of eye disorders and loss of vision. Vitamin B6 rich food like water chest nut is one of the best options for getting sufficient amount of vitamin b6 since it has 0.407 mg of vitamin b6 which is 31.31% of the daily recommended value. Vitamin B6 is considered to help slow the beginning of certain eye diseases as well as age-related macular degeneration.
3. Provide Energy
Almost all regular activities need energy. Even walking or breathing needs energy. The main source of energy required for your daily requirements comes from glucose. The source of glucose is from the starches and sugars you consume. Starches and sugars get broken down to simple sugar with help of insulin during the process of digestion. Glucose is then enters the cell wall. The extra sugar available from food gets stored muscles, liver, or other parts of your body. This then gets converted in fat later. Water chestnut consists of 29.69 g of carbohydrate which is 22.84% of the daily recommended value.
4. Migraine
Those people who do not get sufficient riboflavin have a tendency to experience repeated headaches and even migraines. However, when a person gets enough riboflavin, the number of headaches is reduced. A vitamin b2 or riboflavin rich food like water chestnut is recommended to include in your regular diet to solve this problems. One experimental research of 55 patients displayed that those who took 200-400 mg of riboflavin had considerably fewer migraines and headaches than those given the placebo. Research proves that vitamin b2 help to reduce both the frequency and intensity of the headaches.
5. Helps Prevent Osteoporosis
Manganese along with other minerals, like calcium, copper and zinc can help reduce bone loss, particularly in older women who are more vulnerable to bone fractures and weak bones. Manganese deficiency also poses a risk for bone-related complaints since manganese helps with the formation of bone regulatory hormones and enzymes involved in bone metabolism.
According to research, taking manganese along with other bone-supporting nutrients like calcium, vitamin D, magnesium, zinc, copper and boron can improve bone mass in women with weak bones, which is beneficial to naturally treat osteoporosis. So manganese rich food like water chestnut must be included in your regular diet to prevent osteoporosis problems.
6. Good for the heart
Water chestnut helps to keep the body healthy simply by lowering blood pressure. People suffering from hypertension and congestive heart disease can get significant relief from their symptoms by consuming a high potassium diet. Water chestnut, when included as an essential element in nutrition, helps normalize heartbeat. It also reduces the incidence of heart arrhythmia and heart attack. High potassium foods when combined with a diuretic are known to decrease the incidence of stroke by an astonishing 60% in men.
7. Prevents Alzheimer’s disease
Vitamin B1 found in water chestnut is supposed to slow down the progression of Alzheimer’s disease. People suffering from this disease have benefited when treated with vitamin B1 supplements of 100 mg per day. There are placebo-controlled trial researches that are ongoing to determine more about the mechanism by which this occurs.
8. Helps Wound Healing
Research has shown that vitamin B5 found in water chestnut help in treating skin reactions from radiation therapy and may speed up wound and cut healing. It is also known to delay the appearance of premature aging, like wrinkles and dark spots on the skin.
9. Helps Maintain Dental Health
Phosphorus is essential for maintaining teeth and gum health. Calcium, vitamin D and phosphorus all play an important role in the formation and maintenance of dental health by supporting tooth enamel, jaw-bone mineral density and holding the teeth in place, too — thus, these minerals and vitamins can also help heal tooth decay.
Children particularly need foods high in phosphorus and calcium-rich foods while they are developing adult teeth in order to form teeth’s hard structure. Vitamin D is needed along with phosphorus to regulate the body’s balance of calcium and improve its absorption during tooth formation. Vitamin D can also help to decrease inflammation of gums that is associated with periodontal gum disease. Water chestnut consists of 78 mg of phosphorus which is 11.14% of the daily recommended value.
10. Helps PMS Symptoms
Taking a vitamin E supplement 2-3 days before and 2-3 days after a menstrual period help to reduce anxiety, cramping and cravings that are related to PMS. Water chestnut consists of considerable amount of Vitamin E that help to decrease pain severity and duration, and it can reduce menstrual blood loss. It does this by balancing your hormones naturally and it helps to keep your menstrual cycle regulated.
How to Eat
Corm has a crispy, white flesh and can be consumed raw, somewhat boiled, fried, cooked, grilled, pickled, candied or canned.
Canned and peeled water chestnuts, whole or sliced are normally sold in all Asian food stores around the world.
Corm is a common ingredient in many of the Asian cuisines and delicacies.
They are commonly consumed raw and fresh as dessert, sometimes sweetened in China and Southeast Asia.
Chinese water chestnut may be either used as a vegetable or in starch (flour) manufacture.
Due to its crisp, sweet, apple like flesh, honn matai is extensively eaten out of hand in China as a substitute for fresh fruits.
Chinese water chestnut are sliced, diced, or grated with other vegetables in omelet, soups, chop suey, salads etc. or in stews, curry.
It is often shredded for meat and fish dishes and is used as a common ingredients in stuffing and filling for dim sum.
A peeled metaion bamboo skewer is a popular and common item sold by street or train hawkers.
Minced matai is made into puddings and fritters including matai ko, a kind of cake which is bought from portable made shift kitchens on the street cornersor in tea houses.
Matai is often served boiled or steamed as a winter vegetable sometimes in a sauce of sugar, butter and flour.
Two popular Chinese recipes are jellied water chestnut prepared from ground water chestnut, agar and sugar and water chestnut meatballs made with minced water chestnuts, beef or pork, scallions, ginger, corn starch, salt and soy sauce.
Corms are usually made into chips in Indonesia and the Philippines.
Other traditional uses and benefits of Water Chestnuts
Plant is used to treat a number of ailments like abdominal pain, amenorrhea, hernia and liver problems.
The expressed juice of the tuber is bactericidal.
Other Facts
Stems are used for making sleeping mats in Sumatra, Sulawesi and skirts in Papua New Guinea.