Sunday, November 28, 2010

Healthy Fruit: Pear

The pear is a fruit tree of genus Pyrus and also the name of the tree's edible pomaceous fruit. The pear is classified in subtribe Pyrinae within tribe Pyreae and is a perennial. The apple (Malus × domestica), which it resembles in floral structure, is also a member of this subcategory.
The English word “pear” is probably from Common West Germanic *pera, probably a loanword of Vulgar Latin pira, the plural of pirum, akin to Greek apios which is likely of Semitic origin. The place name Perry can indicate the historical presence of pear trees. The term "pyriform" is sometimes used to describe something which is "pear-shaped".
Pears grow in the sublime orchard of Alcinous, in Odyssey vii: "Therein grow trees, tall and luxuriant, pears and pomegranates and apple-trees with their bright fruit, and sweet figs, and luxuriant olives. Of these the fruit perishes not nor fails in winter or in summer, but lasts throughout the year."
Pears have been cultivated in China for approximately 3000 years. The genus is thought to have originated in present-day western China in the foothills of the Tian Shan, a mountain range of Central Asia, and to have spread to the north and south along mountain chains, evolving into a diverse group of over 20 widely recognized primary species. The enormous number of varieties of the cultivated European pear (Pyrus communis subsp. communis), are without doubt derived from one or two wild subspecies (P. communis subsp. pyraster and P. communis subsp. caucasica), widely distributed throughout Europe, and sometimes forming part of the natural vegetation of the forests.
Asian species with medium to large edible fruit include P. pyrifolia, P. ussuriensis, P. × bretschneideri, P. × sinkiangensis, and P. pashia. Other small-fruited species are frequently used as rootstocks for the cultivated forms.
Pears are native to coastal and mildly temperate regions of the Old World, from western Europe and north Africa east right across Asia. They are medium sized trees, reaching 10–17 m tall, often with a tall, narrow crown; a few species are shrubby. The leaves are alternately arranged, simple, 2–12 cm long, glossy green on some species, densely silvery-hairy in some others; leaf shape varies from broad oval to narrow lanceolate. Most pears are deciduous, but one or two species in southeast Asia are evergreen. Most are cold-hardy, withstanding temperatures between −25 °C and −40 °C in winter, except for the evergreen species, which only tolerate temperatures down to about −15 °C. The flowers are white, rarely tinted yellow or pink, 2–4 cm diameter, and have five petals. Like that of the related apple, the pear fruit is a pome, in most wild species 1–4 cm diameter, but in some cultivated forms up to 18 cm long and 8 cm broad; the shape varies in most species from oblate or globose, to the classic pyriform 'pear-shape' of the European Pear with an elongated basal portion and a bulbous end.
The fruit is composed of the receptacle or upper end of the flower-stalk (the so-called calyx tube) greatly dilated. Enclosed within its cellular flesh is the true fruit: five cartilaginous carpels, known colloquially as the "core". From the upper rim of the receptacle are given off the five sepals, the five petals, and the very numerous stamens. The pear is very similar to the apple in cultivation, propagation and pollination. The pear and the apple are also related to the quince.
Pears and apples cannot always be distinguished by the form of the fruit; some pears look very much like some apples. One major difference is that the flesh of pear fruit contains stone cells (also called "grit"). Pear trees and apple trees do have several visible differences. Another interesting difference is that apples, when placed carefully in water, will float; pears will sink. There are about 30 primary species, major subspecies, and naturally occurring interspecific hybrids of pears.
Pears may be stored at room temperature until ripe. Pears are ripe when flesh around stem gives to gentle pressure. Ripe pears are optimally stored refrigerated, uncovered in a single layer, where they have a shelf life of 2 to 3 days.
Pears are consumed fresh, canned, as juice, and dried. The juice can also be used in jellies and jams, usually in combination with other fruits or berries. Fermented pear juice is called perry or pear cider.
Pears ripen at room temperature. They will ripen faster if placed next to bananas in a fruit bowl. Refrigerate pears to slow further ripening. Pear Bureau Northwest offers tips on ripening and judging ripeness: While the skin on Bartlett pears changes from green to yellow as they ripen, most varieties show little color change as they ripen. Because pears ripen from the inside out, the best way to judge ripeness is to "Check the Neck." To Check the Neck for ripeness, apply gentle thumb pressure to the neck, or stem end of the pear. If it yields to gentle pressure, then the pear is ripe, sweet, and juicy. If it is firm, leave pear at room temperature and Check the Neck daily for ripeness. Source: Pear Bureau Northwest
Health Benefits
Pears are an excellent source of dietary fiber and a good source of Vitamin C. The nutritional content of a medium-sized fresh pear weighing 166 g (5.9 oz) is as follows: 100 calories, 26 g of carbohydrates (16 g sugars and  6 g fibre), 1 g of protein, 190 mg (5%) of potassium, 2% and 10% of the daily value (DV) for calcium and vitamin C.

Pear, raw : Nutritional value per 100 g (3.5 oz)
Energy 242 kJ (58 kcal) | Carbohydrates 15.46 g
Sugars 9.80 g | Dietary fiber 3.1 g | Protein 0.38 g
Thiamine (Vit. B1) 0.012 mg (1%)
Riboflavin (Vit. B2) 0.025 mg (2%)
Niacin (Vit. B3) 0.157 mg (1%)
Pantothenic acid (B5) 0.048 mg (1%) | Vitamin B6 0.028 mg (2%)
Folate (Vit. B9) 7 μg (2%) | Vitamin C 4.2 mg (7%)
Calcium 9 mg (1%) | Iron 0.17 mg (1%)
Magnesium 7 mg (2%) | Phosphorus 11 mg (2%)
Potassium 119 mg (3%) | Zinc 0.10 mg (1%)
Percentages are relative to US recommendations for adults.
Source: USDA Nutrient database
Pears are less allergenic than many other fruits, and pear juice is therefore sometimes used as the first juice introduced to infants. However, caution is recommended for all fruit juice consumption by infants as studies have suggested a link between excessive fruit juice consumption and reduced nutrient intake as well as a tendency towards obesity. Pears are low in salicylates and benzoates and are therefore recommended in exclusion diets for allergy sufferers. Along with lamb and rice, pears may form part of the strictest exclusion diet for allergy sufferers although allergies to these foods are possible.
Pears can be useful in treating inflammation of mucous membranes, colitis, chronic gallbladder disorders, arthritis, and gout. Pears can also be beneficial in lowering high blood pressure, controlling blood cholesterol levels, and increasing urine acidity. In ancient Greece, pears were used to treat nausea. Most of the fiber is insoluble, making pears a good laxative. The gritty fiber content may cut down on the number of cancerous colon polyps. Most of the vitamin C, as well as the dietary fiber, is contained within the skin of the fruit.

Source, Images: http://en.wikipedia.org/wiki/Pear

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