Daily Archives: June 6, 2009

Fruit Of The Week GUAVA

Guava

Guavas are plants in the myrtle family (Myrtaceae) genus Psidium, which contains about 100 species of tropical shrubs and small trees. Native to Mexico and Central America, northern South America. Most likely naturally spreading (by means of ocean drifting) to parts of the Caribbean and some parts of North Africa, guavas are now cultivated and naturalized throughout the tropics, and due to growing demand they are also grown in some subtropical regions.

Facts On The Fruit

The most frequently-encountered species, and the one often simply referred to as “the guava”, is the Apple Guava (Psidium guajava).

Guavas are typical Myrtoideae, with tough dark leaves that are opposite, simple, elliptic to ovate and 5-15 cm long. The flowers are white, with five petals and numerous stamens.

The genera Accara and Feijoa (= Acca, Pineapple Guava) were formerly included in Psidium.

Common Names

The term “guava” appears to derive from Arawak guayabo “guava tree”, via the Spanish guayaba. It has been adapted in many European languages: guava (Swedish, Danish and Norwegian, also Greek Γκουάβα and Russian Гуава), Guave (Dutch and German), goyave (French), gujawa (Polish), goiaba (Portuguese).

Outside of Europe, the Arabic jwafa,the Punjabi “amrud”, the Japanese guaba (グアバ), the Tamil goiyaa, the Tongan kuava and probably also the Tagalog bayabas are ultimately derived from the Arawak term.

Another term for guavas is pera or variants thereof. It is common around the western Indian Ocean and probably derives from Portuguese, which means “pear”, or from some language of southern India, though it is so widespread in the region that its origin cannot be clearly discerned anymore. Pera itself is used in Malayalam, Sinhala and Swahili. In Marathi it is peru, in Bengali pearah, and in Dhivehi feyru.

In northern India and Southeast Asia, there are some other names for guavas which have a more limited use. These include jaam (used in Farsi, Hindi, Punjabi and Urdu). Jaama is used in Telugu, jaamba (in addition to peru) in Marathi, jambu or jambu batu in Indonesian and Malay, and jhamruk or jaamfal in Gujarati. Note that jambu or jumbu may also refer to Syzygium fruit (rose apples or water apples).

The more widespread name for guavas in Northern India is amrood (used in Farsi, Hindi, Punjabi and Urdu as an alternative to jaam), bihi (used in some Central Indian dialects of Hindi), da-bike (Khmer), ổi (Vietnamese, pa̍t-á (Min Nan), peguulli (Oriya), pha-rang (Thai) and seebe kayi (Kannada). In Assam (India), it is known as “Modhuri Aam” in Assamese & the fruit is very popular.

Additional terms for guavas from their native range are, for example, sawintu (Quechua) and xālxocotl (Nāhuatl)

Ecology And Uses

Psidium species are used as food plants by the caterpillars of some Lepidoptera, mainly moths like the Ello Sphinx (Erinnyis ello), Eupseudosoma aberrans, Snowy Eupseudosoma (E. involutum) and Hypercompe icasia. Mites like Pronematus pruni and Tydeus munsteri are known to parasitize the Apple Guava (P. guabaya) and perhaps other species. The bacterium Erwinia psidii causes rot diseases of the Apple Guava.

The fruit are not only relished by humans, but by many mammals and birds as well. The spread of introduced guavas owes much to this fact, as animals will eat the fruit and disperse the seeds in their droppings.

In several tropical regions, including Hawaii, some species (namely Strawberry guava, P. littorale) have become invasive species. On the other hand, several species have become very rare due to habitat destruction and at least one (Jamaican Guava, P. dumetorum), is already extinct.

Guava wood is used for meat smoking in Hawaiʻi and is being used at barbecue competitions across the United States. In Cuba the leaves are also used in barbecues, providing a nice smoked flavor and scent to the meat.

Cultivation For Fruit

Guavas are cultivated in many tropical and subtropical countries for their edible fruit. Several species are grown commercially; Apple Guava (P. guajava) and its cultivars are those most commonly traded internationally.

Mature trees of most species are fairly cold-hardy and can survive as low as 5 °C (41 °F) for short periods of time, but younger plants will not survive. They are known to survive in Northern Pakistan where they can get down to 5°C or lower during the night. Guavas are also of interest to home growers in temperate areas, being one of the very few tropical fruits that can be grown to fruiting size in pots indoors.

Culinary Uses

Guava fruit, usually 4 to 12 cm long, are round or oval depending on the species. The outer skin may be rough, often with a bitter taste, or soft and sweet. Varying between species, the skin can be any thickness, is usually green before maturity, but becomes yellow, maroon, or green when ripe. Guava fruit generally have a pronounced and typical fragrance, similar to lemon rind but less sharp. Guava pulp may be sweet or sour, off-white to deep pink, with the seeds in the central pulp of variable number and hardness, again depending on species.

Guavas in Larkana, PakistanThe fruit is also often prepared as a dessert. In Asia, fresh raw guava is often dipped in preserved prune powder or salt. Because of the skin’s high level of pectin, boiled guava is also extensively used to make candies, preserves, jellies, jams, marmalades (goiabada), and also for juices and aguas frescas. Guava juice is very popular in Mexico, Colombia, Egypt and South Africa. Red guavas can be used as the base of salted products such as sauces, constituting a substitute for tomatoes, especially for those sensitive to the latter’s acidity. In Asia, a tea is made from guava fruits and leaves.

Nutritional Value

Guavas are often marketed as “superfruits”, being rich in vitamins A and C, and if the seeds are eaten too, omega-3 and omega-6 polyunsaturated fatty acids and especially high levels of dietary fiber. A single Apple Guava (P. guajava) fruit contains over four times the amount of vitamin C as a single orange (over 200 mg per 100 g serving) and also has good levels of the dietary minerals, potassium, magnesium, and generally a broad, low-calorie profile of essential nutrients.

However, nutritional value is greatly dependent on species, the Strawberry Guava (P. littorale var. cattleianum) notably containing only 30–40 mg of vitamin C per 100g serving, practically a tenth of the vitamin C found in more common varieties. Vitamin C content in the Strawberry Guava is still a high percentage (62%) of the Dietary Reference Intake however.

‘Thai Maroon’ guavas, a red Apple Guava cultivar extremely rich in antioxidants

Green apple guavas are less rich in antioxidantsGuavas contain both carotenoids and polyphenols – the major classes of antioxidant pigments –, giving them relatively high dietary antioxidant value among plant foods. As these pigments produce the fruits’ color, guavas that are red or orange in color have more potential value as antioxidants sources than yelllowish-green ones.

Medical Uses

Since the 1950s, guavas – particularly the leaves – have been a subject for diverse research in chemical identity of their constituents, pharmacological properties and history in folk medicine; most research has been restricted to the Apple Guava (P. guajava) however, and any additional beneficial properties of other species remain essentially unstudied. From preliminary medical research in laboratory models, extracts from Apple Guava leaves or bark are implicated in therapeutic mechanisms against cancer, bacterial infections, inflammation and pain. Essential oils from guava leaves have shown strong anti-cancer activity in vitro.

Guava leaves are used in folk medicine as a remedy for diarrhea and, as well as the bark, for their supposed antimicrobial properties and as an astringent. Guava leaves or bark are used in traditional treatments against diabetes.

Recipes

You can Find number of different recipes in Ayesha’s Kitchen.

Vegetable Of The Week BITTER MELON

Bitter Mellon

Momordica charantia is a tropical and subtropical vine of the family Cucurbitaceae, widely grown for edible fruit, which is among the most bitter of all vegetables. English names for the plant and its fruit include bitter melon or bitter gourd (translated from Chinese: 苦瓜; pinyin: kǔguā), and karela from the Indian name of the vegetable.

The original home of the species is not known, other than that it is a native of the tropics. It is widely grown in South and Southeast Asia, China, Africa, and the Caribbean.

Description

The herbaceous, tendril-bearing vine grows to 5 m. It bears simple, alternate leaves 4-12 cm across, with 3-7 deeply separated lobes. Each plant bears separate yellow male and female flowers.

The fruit has a distinct warty looking exterior and an oblong shape. It is hollow in cross-section, with a relatively thin layer of flesh surrounding a central seed cavity filled with large flat seeds and pith. Seeds and pith appear white in unripe fruits, ripening to red; they are not intensely bitter and can be removed before cooking. However, the pith will become sweet when the fruit is fully ripe, and the pith’s color will turn red. The pith can be eaten uncooked in this state, but the flesh of the melon will be far too tough to be eaten anymore. Red and sweet bitter melon pith is a popular ingredient in some special southeast Asian style salad. The flesh is crunchy and watery in texture, similar to cucumber, chayote or green bell pepper. The skin is tender and edible. The fruit is most often eaten green. Although it can also be eaten when it has started to ripen and turn yellowish, it becomes more bitter as it ripens. The fully ripe fruit turns orange and mushy, is too bitter to eat, and splits into segments which curl back dramatically to expose seeds covered in bright red pulp.

Bitter melon comes in a variety of shapes and sizes. The typical Chinese phenotype is 20 to 30 cm long, oblong with bluntly tapering ends and pale green in color, with a gently undulating, warty surface. The bitter melon more typical of India has a narrower shape with pointed ends, and a surface covered with jagged, triangular “teeth” and ridges. Coloration is green or white. Between these two extremes are any number of intermediate forms. Some bear miniature fruit of only 6 – 10 cm in length, which may be served individually as stuffed vegetables. These miniature fruit are popular in Southeast Asia as well as India.

Culinary Uses

Bitter melons are seldom mixed with other vegetables due to the strong bitter taste, although this can be moderated to some extent by salting and then washing the cut melon before use.

Bitter melon is often used in Chinese cooking for its bitter flavor, typically in stir-fries (often with pork and douchi), soups, and also as tea.

It is also a popular vegetable in the cuisines of South Asia and the West Indies. In these culinary traditions, it is often prepared with potatoes and served with yogurt on the side to offset the bitterness, or used in sabji. Bitter melon is stuffed with spices and then fried in oil, which is very popular in Punjabi Cuisine. It is a popular food in Tamil Nadu and referred as பாகற்காய் (Pagarkai) slangily called as Pavakkai பாவக்காய். Bitter Gourd is popular in the cuisine of South Indian state of Kerala. They use it for making a dish called thoran mixed with grated coconut, theeyal and pachadi. This is one common medicinal food for diabetics. In Karnataka, the term used for bitter gourd is haagalakai (ಹಾಗಲಕಾಯಿ) and used in preparation of a delicacy called gojju (ಗೊಜ್ಜು). In Andhra Pradesh, it is called as ” Kaakarakaaya ” (కాకరకాయ). Popular recipes are curry, deep fry with peanuts (ground nuts) , ‘Pachi Pulusu’ (కాకరకాయ పచ్చి పులుసు), a kind of soup made up of boiled Bitter Melon, fried onions and other spices.

Bitter melon is rarely used in mainland Japan, but is a significant component of Okinawan cuisine, it is credited with Okinawan life expectancies being significantly higher than already long Japanese ones. Bitter melon oil contains Eleostearic acid, which is shown to prevent angiogenesis, which is implicated in the growth (but not the incidence) of cancer.

In Indonesia, bitter melon is prepared in various dishes, such as stir fry, cooked in coconut milk, or steamed.

In Vietnam, raw bitter melon slices consumed with dried meat floss and stuffed to make bitter melon soup with shrimp are popular dishes. Bitter melons stuffed with ground pork are served as a popular summer soup in the South.

It is prepared in various dishes in the Philippines, where it is known as Ampalaya. Ampalaya may also be stir-fried with ground beef and oyster sauce, or with eggs and diced tomato.

A very popular dish from the Ilocos region of the Philippines, pinakbet, consists mainly of bitter melons, eggplant, okra, string beans, tomatoes, lima beans, and other various regional vegetables stewed with a little bagoong-based stock.

The young shoots and leaves may also be eaten as greens; in the Philippines, where bitter melon leaves are commonly consumed, they are called dahon (leaves) ng ampalaya.

The seeds can also be eaten, and have a sweet taste; but are known to cause nausea In Nepal bitter melon is prepared in various ways. Most prepare it as fresh achar (a type of pickle). For this the bitter gourd is cut into cubes or slices and sautéed covered in little oil and a sprinkle of water. When it is softened and reduced, it is minced in a mortar with few cloves of garlic, salt and a red or green pepper. Another way is the sautéed version. In this, bitter gourd is cut in thin round slices or cubes and fried (sauteed) with much less oil and some salt, cumin and red chili. It is fried until the vegetable softens with hints of golden brown. It is even prepared as a curry on its own, or with potato; and made as stuffed vegetables.

In Pakistan bitter melon is available in the summertime, and is cooked with lots of onions.

A Malaysian-style bitter melon dish, cooked with sambal, onion, and red bird’s-eye chili peppersA traditional way to cook bitter melon curry is to peel off the skin and cut into thin slices. It is salted and exposed to direct sunlight for few hours to reduce its bitterness. After a few hours, its salty, bitter water is reduced by squeezing out the excess by hand. Then it’s rinsed with water a few times. Then fried in cooking oil, with onions also fried in another pan. When the onions have turned a little pink in color, the fried bitter melon is added to them. After some further frying of both the onions and bitter melon, red chili powder, turmeric powder, salt, coriander powder, and a pinch of cumin seeds are also added. A little water can be sprinkled while frying the spices to prevent burning. Then a good amount of tomato is added to the curry, with green chillies, according to taste. Now the pan is covered with a lid, heat reduced to minimum, the tomatoes reduce, and all the spices work their magic. The curry is stirred a few times (at intervals) during this covering period. After half an hour or so, the curry is ready to serve, with soft hot flatbreads (chappatis, چپاتی) and yogurt chutney.

Another dish in Pakistan calls for whole, unpeeled bitter melon to be boiled and then stuffed with cooked ground beef. In this dish, it is recommended that the bitter melon be left ‘debittered’. It is either served with hot tandoori bread, naan, chappati, or with khichri (a mixture of lentils and rice).

Medicinal Uses

Bitter melon has been used in various Asian traditional medicine systems for a long time [1]. Like most bitter-tasting foods, bitter melon stimulates digestion. While this can be helpful in people with sluggish digestion, dyspepsia, and constipation, it can sometimes make heartburn and ulcers worse. The fact that bitter melon is also a demulcent and at least mild inflammation modulator, however, means that it rarely does have these negative effects, based on clinical experience and traditional reports.

Though it has been claimed that bitter melon’s bitterness comes from quinine, no evidence could be located supporting this claim. Bitter melon is traditionally regarded by Asians, as well as Panamanians and Colombians, as useful for preventing and treating malaria. Laboratory studies have confirmed that various species of bitter melon have anti-malarial activity, though human studies have not yet been published.

In Panama bitter melon is known as Balsamino. The pods are smaller and bright orange when ripe with very sweet red seeds, but only the leaves of the plant are brewed in hot water to create a tea to treat malaria and diabetes. The leaves are allowed to steep in hot water before being strained thoroughly so that only the remaining liquid is used for the tea.

Laboratory tests suggest that compounds in bitter melon might be effective for treating HIV infection. As most compounds isolated from bitter melon that impact HIV have either been proteins or glycoproteins lectins), neither of which are well-absorbed, it is unlikely that oral intake of bitter melon will slow HIV in infected people. It is possible oral ingestion of bitter melon could offset negative effects of anti-HIV drugs, if a test tube study can be shown to be applicable to people. In one preliminary clinical trial, an enema form of a bitter melon extract showed some benefits in people infected with HIV (Zhang 1992). Clearly more research is necessary before this could be recommended.

The other realm showing the most promise related to bitter melon is as an immunomodulator. One clinical trial found very limited evidence that bitter melon might improve immune cell function in people with cancer, but this needs to be verified and amplified in other research. If proven correct this is another way bitter melon could help people infected with HIV.

Folk wisdom has it that ampalaya (Momordica charantia Linn.) helps to prevent or counteract type-II diabetes. A recent scientific study at JIPMER, India has proved that ampalaya increases insulin sensitivity. Also, in 2007, the Philippine Department of Health issued a circular stating that Ampalaya as a scientifically validated herbal medicinal plant, can lower elevated blood sugar levels. It is sold in the Philippines as a food supplement and marketed under the trade name Ampalaya Plus and the like. The study revealed that a 100 milligram per kilo dose per day is comparable to 2.5 milligrams of the anti-diabetes drug Glibenclamide taken twice per day.

Bitter melon transformed into capsule form and sold as a food supplement.Bitter Melon contains four very promising bioactive compounds. These compounds activate a protein called AMPK, which is well known for regulating fuel metabolism and enabling glucose uptake, processes which are impaired in diabetics. “We can now understand at a molecular level why bitter melon works as a treatment for diabetes,” said David James, director of the diabetes and obesity program at the Garvan Institute of Medical Research in Sydney. “By isolating the compounds we believe to be therapeutic, we can investigate how they work together in our cells.”

Bitter melon contains a lectin that has insulin-like activity. The insulin-like bioactivity of this lectin is due to its linking together 2 insulin receptors. This lectin lowers blood glucose concentrations by acting on peripheral tissues and, similar to insulin’s effects in the brain, suppressing appetite. This lectin is likely a major contributor to the hypoglycemic effect that develops after eating bitter melon and why it may be a way of managing adult-onset diabetes. Lectin binding is non-protein specific, and this is likely why bitter melon has been credited with immunostimulatory activity – by linking receptors that modulate the immune system, thereby stimulating said receptors.

Various cautions are indicated. The seeds contains vicine and therefore can trigger symptoms of favism in susceptible individuals. In addition, the red arils of the seeds are reported to be toxic to children, and the fruit is contraindicated during pregnancy.

Recipe:

You can Find number of recipes in Ayesha’s Kitchen.