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Other [[species]] that were previously thought to have made contributions to the [[genome]] of the domestic apples are ''[[Malus baccata]]'' and ''[[Malus sylvestris]]'', but there is no hard evidence for this in older apple [[cultivar]]s. These and other ''Malus'' species have been used in some recent breeding programmes to develop apples suitable for growing in climates unsuitable for ''M. domestica'', mainly for increased cold tolerance.{{Fact|date=February 2007}}
Other [[species]] that were previously thought to have made contributions to the [[genome]] of the domestic apples are ''[[Malus baccata]]'' and ''[[Malus sylvestris]]'', but there is no hard evidence for this in older apple [[cultivar]]s. These and other ''Malus'' species have been used in some recent breeding programmes to develop apples suitable for growing in climates unsuitable for ''M. domestica'', mainly for increased cold tolerance.{{Fact|date=February 2007}}


The apple tree was perhaps the earliest tree to be cultivated, and apples have remained an important food in all cooler climates. To a greater degree than other tree fruit, except possibly [[citrus]], apples store for months while still retaining much of their nutritive value. Winter apples, picked in late autumn and stored just above freezing, have been an important food in [[Asia]] and [[Europe]] for millennia, as well as in [[Argentina]] and in the [[United States]] since the [[Immigration to the United States|arrival of Europeans]].{{Fact|date=February 2007}}
The apple tree was perhaps the earliest tree to be cultivated, and apples have remained an important food in all cooler climates. To a greater degree than other tree fruit, except possibly [[citrus]], apples store for months while still retaining much of their nutritive value. Winter apples, picked in late autumn and stored just above freezing, have been an important food in [[Asia]] and [[Europe]] for millennia, as well as in [[Argentina]] and in the [[United States]] since the [[Immigration to the United States|arrival of Europeans]].{{Fact|date=February 2007}} The importance of the apple as a fruit is shown by the popular belief that [[Adam and Eve]] ate a forbidden apple in the [[Garden of Eden]], leading to [[the Fall of Man]]; in actuality, [[Genesis]] only mentions "fruit", and apples were unknown in the ancient [[Levant]].


==Apple cultivars==
==Apple cultivars==

Revision as of 18:37, 2 January 2008

Apple
Blossoms, fruits, and leaves of the apple tree (Malus domestica)
Scientific classification
Kingdom:
Division:
Class:
Order:
Family:
Subfamily:
Genus:
Species:
M. domestica
Binomial name
Malus domestica
Wild Malus sieversii apple in Kazakhstan
Apple cut horizontally, showing seeds

The apple is the pomaceous fruit of the apple tree, species Malus domestica in the rose family Rosaceae. It is one of the most widely cultivated tree fruits. The tree is small and deciduous, reaching 5-12 m tall, with a broad, often densely twiggy crown.

The leaves are alternately arranged simple ovals 5-12 cm long and 3-6 cm broad on a 2-5 cm petiole with an acute tip, serrated margin and a slightly downy underside. Flowers are produced in spring simultaneous with the budding of the leaves.

The flowers are white with a pink tinge that gradually fades, five petaled, 2.5-3.5 cm in diameter. The fruit matures in autumn, and is typically 5-9 cm diameter. The centre of the fruit contains five carpels arranged in a five-point star, each carpel containing one to three seeds.

Botanical information

The wild ancestor of Malus domestica is Malus sieversii. It has no common name in English, but is known in Kazakhstan, where it is native, as 'alma'; in fact, the region where it is thought to originate is called Alma-Ata, or 'father of the apples'. This tree is still found wild in the mountains of Central Asia in southern Kazakhstan, Kyrgyzstan, Tajikistan, and Xinjiang, China.

For many years, there was a debate about whether M. domestica evolved from chance hybridisation among various wild species. Recent DNA analysis by Barrie Juniper, Emeritus Fellow in the Department of Plant Sciences at Oxford University and others, has indicated, however, that the hybridisation theory is probably false. Instead, it appears that a single species still growing in the Ili Valley on the northern slopes of the Tien Shan mountains at the border of northwest China and the former Soviet Republic of Kazakhstan is the progenitor of the apples we eat today. Leaves taken from trees in this area were analyzed for DNA composition, which showed them all to belong to the species M. sieversii, with some genetic sequences common to M. domestica.[citation needed]

Some individual M. sieversii, recently planted by the US government at a research facility, resist many diseases and pests that affect domestic apples, and are the subject of continuing research to develop new disease-resistant apples.

Other species that were previously thought to have made contributions to the genome of the domestic apples are Malus baccata and Malus sylvestris, but there is no hard evidence for this in older apple cultivars. These and other Malus species have been used in some recent breeding programmes to develop apples suitable for growing in climates unsuitable for M. domestica, mainly for increased cold tolerance.[citation needed]

The apple tree was perhaps the earliest tree to be cultivated, and apples have remained an important food in all cooler climates. To a greater degree than other tree fruit, except possibly citrus, apples store for months while still retaining much of their nutritive value. Winter apples, picked in late autumn and stored just above freezing, have been an important food in Asia and Europe for millennia, as well as in Argentina and in the United States since the arrival of Europeans.[citation needed] The importance of the apple as a fruit is shown by the popular belief that Adam and Eve ate a forbidden apple in the Garden of Eden, leading to the Fall of Man; in actuality, Genesis only mentions "fruit", and apples were unknown in the ancient Levant.

Apple cultivars

See List of apple cultivars for a listing.

There are more than 7,500 known cultivars of apples. Different cultivars are available for temperate and subtropical climates. Reputedly the world's biggest collection of apple cultivars is housed at the National Fruit Collection in England. Apples do not flower in tropical climates because they have a chilling requirement.

Different kinds of apple cultivars in a supermarket
A cross section and whole Granny Smith

Commercially popular apple cultivars are soft but crisp. Other desired qualities in modern commercial apple breeding are a colourful skin, absence of russeting, ease of shipping, lengthy storage ability, high yields, disease resistance, typical "Red Delicious" apple shape, long stem (to allow pesticides to penetrate the top of the fruit), and popular flavour. The taste of the apple doesn't depend on the colour. If the apple is bright red it could still taste bad.

Old cultivars are often oddly shaped, russeted, and have a variety of textures and colours. Many of them have excellent flavour (often better than most modern cultivars), but may have other problems which make them commercially unviable, such as low yield, liability to disease, or poor tolerance for storage or transport. A few old cultivars are still produced on a large scale, but many have been kept alive by home gardeners and farmers that sell directly to local markets. Many unusual and locally important cultivars with their own unique taste and appearance are out there to discover; apple conservation campaigns have sprung up around the world to preserve such local cultivars from extinction. In the United Kingdom old cultivars such as Cox's Orange Pippin and Egremont Russett are still commercially important even though by modern standards they are low yielding and disease prone.

Although most cultivars are bred for eating fresh (dessert apples), some are cultivated specifically for cooking (cooking apples) or producing cider. Cider apples are typically too tart and astringent to eat fresh, but they give the beverage a rich flavour that dessert apples cannot.

Modern apples are, as a rule, sweeter than older cultivars. Most North Americans and Europeans favour sweet, subacid apples, but tart apples have a strong minority following. Extremely sweet apples with barely any acid flavour are popular in Asia and especially India.

Tastes in apples vary from one person to another and change continually over time. As an example, the U.S. state of Washington made its reputation for apple growing on Red Delicious. In recent years, many apple connoisseurs have come to regard the Red Delicious as inferior to cultivars such as Fuji and Gala due to its merely mild flavour and insufficiently firm texture.

Growing apples

Apple breeding

In this hybrid of an orchard apple with a red-fruited crabapple cultivar, the pulp is of the same colour as the peel.
Seeds of the above apple, which are same colour as the rest of the fruit.
Apple tree in flower

Like most perennial fruits, apples ordinarily propagate asexually by grafting. Seedling apples are different from their parents, sometimes radically. Most new apple cultivars originate as seedlings, which either arise by chance or are bred by deliberately crossing cultivars with promising characteristics. The words 'seedling', 'pippin', and 'kernel' in the name of an apple cultivar suggest that it originated as a seedling. Apples can also form bud sports (mutations on a single branch). Some bud sports turn out to be improved strains of the parent cultivar. Some differ sufficiently from the parent tree to be considered new cultivars.

Some breeders have crossed ordinary apples with crabapples or unusually hardy apples in order to produce hardier cultivars. For example, the Excelsior Experiment Station of the University of Minnesota has, since the 1930s, introduced a steady progression of important hardy apples that are widely grown, both commercially and by backyard orchardists, throughout Minnesota and Wisconsin. Its most important introductions have included 'Haralson' (which is the most widely cultivated apple in Minnesota), 'Wealthy', 'Honeygold', and 'Honeycrisp'. [1]

Pollination

Apples are self-incompatible; they must cross-pollinate to develop fruit. During the flowering each season, apple growers usually provide pollinators to carry the pollen. Honeybee hives are most commonly used. Orchard mason bees are also used as supplemental pollinators in commercial orchards. Bumble bee queens are sometimes present in orchards, but not usually in enough quantity to be significant pollinators.

There are four to seven pollination groups in apples depending on climate:

One cultivar can be pollinized by a compatible cultivar from the same group or close (A with A or A with B but not A with C or D).

Apple tree ready for harvest

Maturation and harvest

Cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock. Some cultivars, if left unpruned, will grow very large, which allows them to bear a great deal more fruit, but makes harvest very difficult. Mature trees typically bear 40-200 kg of apples each year, though productivity can be close to zero in poor years. Apples are harvested using three-point ladders that are designed to fit amongst the branches. Dwarf trees will bear about 10-80 kg of fruit per year.

Pests and diseases

The trees are susceptible to a number of fungal and bacterial diseases and insect pests. Nearly all commercial orchards pursue an aggressive program of chemical sprays to maintain high fruit quality, tree health, and high yields. A trend in orchard management is the use of organic methods. These use a less aggressive and direct methods of conventional farming. Instead of spraying potent chemicals, often shown to be potentially dangerous and maleficent to the tree in the long run, organic methods include encouraging or discouraging certain cycles and pests.

Leaves with significant insect damage.
An apple rotting on the stem

To control a specific pest, organic growers might encourage the prosperity of its natural predator instead of outright killing it, and with it the natural biochemistry around the tree. Organic apples generally have the same or greater taste than conventionally grown apples, with reduced cosmetic appearances.

Among the most serious disease problems are fireblight, a bacterial disease; and Gymnosporangium rust, apple scab, and black spot, three fungal diseases.

The plum curculio is the most serious insect pest. Others include Apple maggot and codling moth.

Young apple trees are also prone to mammal pests like mice and deer, which feed on the soft bark of the trees, especially in winter.

Organic apples are commonly produced in the United States.[2] Organic production is difficult in Europe, though a few orchards have done so with commercial success, using disease-resistant cultivars and the very best cultural controls. The latest tool in the organic repertoire is a spray of a light coating of kaolin clay, which forms a physical barrier to some pests, and also helps prevent apple sun scald.

Commerce

Apple output in 2005

At least 55 million tonnes of apples were grown worldwide in 2005, with a value of about $10 billion. China produced about two-fifth of this total. United States is the second leading producer, with more than 7.5% of the world production. Turkey, France, Italy and Iran are among the leading apple exporters.

In the United States, more than 60% of all the apples sold commercially are grown in Washington state. Imported apples from New Zealand and other more temperate areas are competing with US production and increasing each year.

A display of different apples

Apples as food

Different cultivars of apples have a distinct different taste, and this can be separated into two separate factors of flavour and texture.

Apples can be canned, juiced, and optionally fermented to produce apple juice, cider, ciderkin, vinegar, and pectin. Distilled apple cider produces the spirits applejack and Calvados. Apple wine can also be made. They make a popular lunchbox fruit as well.

Apples are an important ingredient in many winter desserts, for example apple pie, apple crumble, apple crisp and apple cake. They are often eaten baked or stewed, and they can also be dried and eaten or re-constituted (soaked in water, alcohol or some other liquid) for later use. Puréed apples are generally known as apple sauce. Apples are also made into apple butter and apple jelly. They are also used cooked in meat dishes.

  • In the UK, a toffee apple is a traditional confection made by coating an apple in hot toffee and allowing it to cool. Similar treats in the US are candy apples (coated in a hard shell of crystallised sugar syrup), and caramel apples, coated with cooled caramel.
  • Apples are eaten with honey at the Jewish New Year of Rosh Hashanah to symbolize a sweet new year.
  • Farms with apple orchards may open them to the public, so consumers may themselves pick the apples they will buy.

Sliced apples turn brown with exposure to air due to the conversion of natural phenolic substances into melanin upon exposure to oxygen. Different cultivars differ in their propensity to brown after slicing. Sliced fruit can be treated with acidulated water to prevent this effect.

Health benefits

Apples, with skin (edible parts)
Nutritional value per 100 g (3.5 oz)
Energy218 kJ (52 kcal)
13.81 g
Sugars10.39 g
Dietary fiber2.4 g
0.17 g
0.26 g
VitaminsQuantity
%DV
Thiamine (B1)
1%
0.017 mg
Riboflavin (B2)
2%
0.026 mg
Niacin (B3)
1%
0.091 mg
Pantothenic acid (B5)
1%
0.061 mg
Vitamin B6
2%
0.041 mg
Folate (B9)
1%
3 μg
Vitamin C
5%
4.6 mg
MineralsQuantity
%DV
Calcium
0%
6 mg
Iron
1%
0.12 mg
Magnesium
1%
5 mg
Phosphorus
1%
11 mg
Potassium
4%
107 mg
Zinc
0%
0.04 mg
Percentages estimated using US recommendations for adults,[3] except for potassium, which is estimated based on expert recommendation from the National Academies.[4]

An old proverb attests to the health benefits of the fruit: "An apple a day keeps the doctor away." Research suggests that apples may reduce the risk of colon cancer, prostate cancer and lung cancer.[5] Like many fruits, apples contain Vitamin C as well as a host of other antioxidant compounds, which may reduce the risk of cancer by preventing DNA damage. The fiber content, while less than in most other fruits, helps regulate bowel movements and may thus reduce the risk of colon cancer. They may also help with heart disease, weight loss and controlling cholesterol, as they do not have any cholesterol, have fibre (which reduces cholesterol by preventing reabsorption), and are bulky for their caloric content like most fruits and vegetables.

There is evidence that in vitro, apples possess phenolic compounds which may be cancer-protective and demonstrate antioxidant activity.[6] The predominant phenolic phytochemicals in apples are quercetin, epicatechin, and procyanidin B2.[7]

The seeds are mildly poisonous, containing a small amount of amygdalin, a cyanogenic glycoside, but a large amount would need to be chewed to have any toxic effect.[8]

Cultural aspects

For the allegorical use of the apple in religion, mythology and folktales, as well as other cultural aspects, see : Apple symbolism.

Apples appear in many religious traditions, often as a mystical and forbidden fruit. One of the problems identifying apples in religion, mythology and folktales is that the word "apple" was used as a generic term for all fruit, other than berries but including nuts, as late as the 1600s.

Storage

Commercially, apples can be stored for some months in controlled-atmosphere chambers to delay ethylene-induced onset of ripening. Ripening begins when the fruit is removed.[9] For home storage, most varieties of apple can be stored for approximately two weeks, when kept at the coolest part of the refrigerator. Some types of apple, including the Granny Smith and Fuji, have an even longer shelf life.[10]

See also

References

  1. ^ Stalking the Placid Apple’s Untamed Kin; By HAROLD McGEE; Published: November 21, 2007; NY Times
  2. ^ http://www.bestapples.com/facts/organic.html The Best Organic Apples On Earth
  3. ^ United States Food and Drug Administration (2024). "Daily Value on the Nutrition and Supplement Facts Labels". FDA. Archived from the original on 2024-03-27. Retrieved 2024-03-28.
  4. ^ National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Food and Nutrition Board; Committee to Review the Dietary Reference Intakes for Sodium and Potassium (2019). Oria, Maria; Harrison, Meghan; Stallings, Virginia A. (eds.). Dietary Reference Intakes for Sodium and Potassium. The National Academies Collection: Reports funded by National Institutes of Health. Washington, DC: National Academies Press (US). ISBN 978-0-309-48834-1. PMID 30844154. Archived from the original on 2024-05-09. Retrieved 2024-06-21.
  5. ^ Information about cancer, from Stanford comprehensive cancer center.
  6. ^ Lee KW, Lee SJ, Kang NJ, Lee CY, Lee HJ (2004). "Effects of phenolics in Empire apples on hydrogen peroxide-induced inhibition of gap-junctional intercellular communication". Biofactors. 21 (1–4): 361–5. PMID 15630226.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  7. ^ Lee KW, Kim YJ, Kim DO, Lee HJ, Lee CY (2003). "Major phenolics in apple and their contribution to the total antioxidant capacity". J. Agric. Food Chem. 51 (22): 6516–20. doi:10.1021/jf034475w. PMID 14558772.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  8. ^ "Raw Food Toxins". Retrieved 2006-09-16. {{cite web}}: Text "RawVeg.info" ignored (help)
  9. ^ Controlled Atmosphere Storage
  10. ^ Food Science Australia (February, 2005). "Food Science Australia Fact Sheet: Refrigerated storage of perishable foods". Retrieved 2007-05-25. {{cite web}}: Check date values in: |date= (help)

External links

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