The
potato is a
starchy,
tuberous crop from the
perennial Solanum
tuberosum of the
Solanaceae family
(also known as the nightshades). The word potato may refer to the
plant itself as well. In the region of the
Andes, there are some other closely related cultivated
potato species. Potatoes are the world's fourth largest food crop,
following
rice,
wheat, and
maize. Long-term storage of potatoes requires
specialised care in cold warehouses and such warehouses are among
the oldest and largest storage facilities for perishable goods in
the world.
Wild
potato species occur from the United States to Uruguay and
Peru. Genetic testing of the wide variety of
cultivars and wild species suggest that the
potato has a single origin in the area of southern Peru, from a
species in the Solanum brevicaule complex.
Although
Peru is essentially the birthplace of the potato, today
over 99% of all cultivated potatoes worldwide are descendants of a
subspecies indigenous to south-central Chile.
Based on historical records, local agriculturalists, and
DNA analyses, the most widely cultivated variety
worldwide,
Solanum tuberosum ssp. tuberosum, is believed
to be indigenous to the
Chiloé
Archipelago where it was cultivated as long as 10,000 years
ago.
Introduced to Europe in 1536, the potato was subsequently conveyed
by European mariners to territories and ports throughout the world.
Thousands of varieties persist in the Andes, where over 100
cultivars might be found in a single valley, and a dozen or more
might be maintained by a single agricultural household. Once
established in Europe, the potato soon became an important food
staple and field crop. But lack of genetic diversity, due to the
fact that very few varieties were initially introduced, left the
crop vulnerable to disease. In 1845, a plant disease known as late
blight, caused by the fungus-like
oomycete
Phytophthora
infestans, spread rapidly through the poorer communities
of western Ireland, resulting in the crop failures that led to the
Great Irish Famine. The potato
was the first vegetable inherited by the early
Australians, the
Aborigines.
The annual diet of an average global citizen in the first decade of
the twenty-first century would include about 33 kg (or
73 lb) of potato. However, the local importance of potato is
extremely variable and rapidly changing. It remains an essential
crop in Europe (especially eastern and central Europe), where per
capita production is still the highest in the world, but the most
rapid expansion over the past few decades has occurred in southern
and eastern Asia. China is now the world's largest potato-producing
country, and nearly a third of the world's potatoes are harvested
in China and India. More generally, the geographic shift of potato
production has been away from wealthier countries toward
lower-income areas of the world, although the degree of this trend
is ambiguous.
Etymology
The English word
potato comes from Spanish
patata
(the name used in Spain). The
Spanish Royal Academy says the Spanish
word is a compound of the
Taino
batata (
sweet potato) and the
Quechua papa (potato). The name
potato originally referred to a type of sweet potato rather than
the other way around, despite the fact that there is actually no
close relationship between the two plants at all. The English
confused the two plants one for the other. In many of the
chronicles detailing agriculture and plants, no distinction is made
between the two. The 16th-century English herbalist
John Gerard used the terms "Bastard potatoes"
and "Virginia potatoes" for this species and referred to sweet
potatoes as "common Potatoes". Potatoes are occasionally referred
to as "Irish potatoes" or "White potatoes" in the United States, to
distinguish them from
sweet
potatoes.
Description
Flowers of a potato plant
Flowers of a potato plant.
Potato plants are herbaceous
perennials
that grow about 60 cm (24 in) high, depending on variety,
the
culms dying back after flowering.
They bear white, pink, red, blue, or purple
flowers with yellow
stamens.
The tubers of varieties with white flowers generally have white
skins, while those of varieties with colored flowers tend to have
pinkish skins. Potatoes are
cross-pollinated mostly by
insects, including
bumblebees, which carry pollen from other potato
plants, but a substantial amount of self-fertilizing occurs as
well. Tubers form in response to decreasing day length, although
this tendency has been minimized in commercial varieties.
Potato plants
After potato plants flower, some varieties will produce small green
fruits that resemble green
cherry
tomatoes, each containing up to 300 true
seeds. Potato fruit contains large amounts of the toxic
alkaloid solanine
and is therefore unsuitable for consumption. All new potato
varieties are grown from seeds, also called "true seed" or
"botanical seed" to distinguish it from seed tubers. By finely
chopping the fruit and soaking it in water, the seeds will separate
from the flesh by sinking to the bottom after about a day (the
remnants of the fruit will float). Any potato variety can also be
propagated vegetatively by
planting tubers, pieces of tubers, cut to include at least one or
two eyes, or also by cuttings, a practice used in greenhouses for
the production of healthy seed tubers. Some commercial potato
varieties do not produce
seeds at all (they
bear imperfect flowers) and are propagated only from tuber pieces.
Confusingly, these tubers or tuber pieces are called "seed
potatoes".
Genetics
The major species grown worldwide is
Solanum tuberosum (a
tetraploid with 48
chromosomes), and modern varieties of this
species are the most widely cultivated. There are also four diploid
species (with 24 chromosomes):
Solanum stenotomum, Solanum
phureja, Solanum goniocalyx and
Solanum ajanhuiri.
There are two triploid species (with 36 chromosomes):
Solanum
chaucha and
Solanum juzepczukii. There is one
pentaploid cultivated species (with 60 chromosomes):
Solanum
curtilobum.
There are two major subspecies of
Solanum tuberosum:
andigena, or Andean; and
tuberosum, or Chilean.
The Andean potato is adapted to the short-day conditions prevalent
in the mountainous equatorial and tropical regions where it
originated. The Chilean potato is adapted to the long-day
conditions prevalent in the higher latitude region of southern
Chile, especially on
Chiloé
Archipelago where it is thought to have originated.
Genetic
testing done in 2005 shows that both species derive from a single
origin in the area of southern Peru.
There are about five-thousand potato varieties worldwide. Three
thousand of them are found in the Andes alone, mainly in Peru,
Bolivia, Ecuador, Chile and Colombia. They belong to eight or nine
species, depending on the taxonomic school. Apart from the
five-thousand cultivated varieties, there are about 200 wild
species and subspecies, many of which can be cross-bred with
cultivated varieties, which has been done repeatedly to transfer
resistances to certain pests and diseases from the gene pool of
wild species to the gene pool of cultivated potato species.
Genetically modified
varieties have met public resistance in the United States and in
the European Union.
Most modern potatoes grown in North America arrived through
European settlement and not independently from the South American
sources. However, at least one wild potato species,
Solanum
fendleri, is found as far north as Texas and used in breeding
for resistance to a
nematode species that
attacks cultivated potatoes. A secondary center of genetic
variability of the potato is Mexico, where important wild species
are found that have been used extensively in modern breeding, such
as the hexaploid
Solanum demissum, as a source of
resistance to the devastating late blight disease. Another relative
native to this region,
Solanum
bulbocastanum, has been used to genetically engineer the
potato to resist potato blight.
The
International Potato
Center, based in Lima,
Peru, holds an ISO-accredited
collection of potato germplasm.
History
Potatoes yield abundantly with little effort, and adapt readily to
diverse climates so long as the climate is cool and moist enough
for the plants to gather sufficient water from the soil to form the
starchy tubers. Potatoes do not keep very well in storage and are
vulnerable to molds that feed on the stored tubers, quickly turning
them rotten. By contrast grain can be stored for several years
without much risk of rotting.
Spread
Peru
The potato
originated in the region of southern Peru.
However, based on historical records, local agriculturalists, and
DNA analyses, the most widely cultivated variety
worldwide,
Solanum tuberosum ssp. tuberosum, is believed
to be a variation indigenous to the
Chiloé Archipelago where it was
cultivated as long as 10,000 years ago.
Potatoes were first domesticated in Peru between 3000 BC and 2000
BC. In the altiplano, potatoes provided the principal energy source
for the
Inca Empire, its predecessors
and its Spanish successor. In Peru above 10,000 feet altitude,
tubers exposed to the cold night air turned into chuño; when kept
in permanently-frozen underground storehouses, chuño can be stored
for years with no loss of nutritional value. The Spanish fed chuño
to the silver miners who produced vast wealth in the 16th century
for the Spanish government.
Europe
Sailors returning from Peru to Spain with silver presumably brought
maize and potatoes for their own food on the trip. Historians
speculate that leftover tubers (and maize) was carried ashore and
planted. Basque fishermen from Spain used potatoes as ships stores
for their voyages across Atlantic in the 15th century, and
introduced the tuber to western Ireland, where they landed to dried
their cod. In 1580, English adventurer
Francis Drake introduced potatoes into England
along with his other Spanish booty when he returned from his famous
circumnavigation of the globe. In 1588 botanist Carolus Clusius
made a painting of what he called "Papas Peruanorum" from a
specimen in Belgium; in 1601 he reported that potatoes were in
common use in northern Italy for animal fodder and for human
consumption.
The Spanish had an empire across Europe, and brought potatoes for
their armies. Peasants along the way adopted the crop, which was
less often pillaged by marauding armies than above-ground stores of
grain. Across most of northern Europe, where open fields prevailed,
potatoes were strictly confined to small garden plots because field
agriculture was strictly governed by custom that prescribed
seasonal rhythms for plowing, sowing, harvesting and grazing
animals on fallow and stubble. This meant that potatoes were barred
from large-scale cultivation because the rules allowed only grain
to be planted in the open fields. In France and Germany government
officials and noble landowners promoted the rapid conversion of
fallow land into potato fields after 1750. The potato thus became
an important
staple crop in northern
Europe. Famines in the early 1770s contributed to its acceptance,
as did government policies in several European countries and
climate change during the
Little Ice
Age, when traditional crops in this region did not produce as
reliably as before. At times when and where most other crops would
fail, potatoes could still typically be relied upon to contribute
adequately to food supplies during the colder years.
The potato was not popular in France before 1800. It took time to
be popularly adopted, but had widely replaced the
turnip and
rutabaga by the
nineteenth century. Today, the potato forms an important part of
the traditional cuisines of most of Europe.
Belarus has the
highest consumption of potato per capita,
with each Belorussian consuming 338 kg in 2005—about two
pounds per person per day.
19th century Europe
French physician Antoine Parmentier studied the potato intensely
and in
Examen chymique des pommes de terres (Paris, 1774)
showed their enormous nutritional value. King
Louis XVI and his court eagerly promoted the new
crop, with Queen Marie Antoinette even wearing a headdress of
potato flowers at a fancy dress ball. The annual potato crop of
France soared to 21 million hectoliters in 1815 and 117 millions in
1840, allowing a concomitant growth in population while avoiding
the Malthusian trap. Although potatoes had become widely familiar
in Russia by 1800, they were confined to garden plots until the
grain failure in 1838–1839 persuaded peasants and landlords in
central and northern Russia to devote their fallow fields to
raising potatoes. Potatoes yielded from two to four times more
calories per acre than grain did, and eventually came to dominate
the food supply in eastern Europe. Boiled or baked potatoes were
cheaper than rye bread, just as nutritious, and did not require a
gristmill for grinding. On the other hand cash-oriented landlords
realized that grain was much easier to ship, store and sell, so
both grain and potatoes coexisted.
Throughout Europe the most important new food in the 19th century
was the potato, which had three major advantages over other foods:
its lower rate of spoilage, its bulk (which easily satisfied
hunger), and its cheapness. The crop slowly spread across Europe,
such that, for example, by 1845 it occupied one-third of Irish
arable land. Potatoes comprised about 10% of the caloric intake of
Europeans. Other foods imported from the New World included cod,
sugar, rice, flour, and rum. These also provided an additional 10%
of daily calories and proved a crucial factor in biodiversity of
crops, thus preventing famines.
In Britain the potato promoted economic development by underpinning
the
Industrial Revolution in
the 19th century. As a cheap source of calories and nutrients that
was easy for urban workers to cultivate on small backyard plots.
Potatoes became popular in the north of England, where coal was
readily available, so a potato-driven population boom provided
ample workers for the new factories. Marxist
Friedrich Engels even declared that the
potato was the equal of iron for its "historically revolutionary
role. The Dutch potato-starch industry grew rapidly in the 19th
century, especially under the leadership of entrepreneur Willem
Albert Scholten (1819–92).
Ireland
In Ireland the expansion of potato cultivation was due entirely to
the landless laborers, renting tiny plots from landowners who were
interested only in raising cattle or in producing grain for market.
A single acre of potatoes and the milk of a single cow was enough
to feed a whole Irish family a monotonous but nutritionally
adequate diet for a healthy, vigorous (and desperately poor) rural
population. Often even poor families grew enough extra potatoes to
feed a pig which could be sold for cash.
A lack of genetic diversity from the low number of varieties left
the crop vulnerable to disease. In 1845, a plant disease known as
late blight, caused by the fungus-like
oomycete Phytophthora infestans, spread
rapidly through the poorer communities of western Ireland,
resulting in the crop failures that led to the
Great Irish Famine.
The Lumper potato, widely cultivated in western and southern
Ireland before and during the great famine, was tasteless, wet, and
poorly resistant to the potato blight, but yielded large crops and
usually provided adequate calories for peasants and laborers. Heavy
dependence on this potato led to disaster when the potato blight
turned a newly harvested potato into a putrid mush in minutes. The
Irish Famine in the western and
southern parts of the British-controlled island of Ireland,
1845–49, was a catastrophic failure in the food supply that led to
approximately a million deaths from famine and (especially)
diseases that attacked weakened bodies, and to massive emigration
to Britain, the U.S. and Canada.
Asia
The potato diffused widely after 1600, becoming a major food
resource in Europe and East Asia. Following its introduction into
China toward the end of the Ming dynasty, the potato immediately
became a delicacy of the imperial family. After the middle period
of the Qianlong reign (1735–96), population increases and a
subsequent need to increase grain yields coupled with greater
peasant geographic mobility, led to the rapid spread of potato
cultivation throughout China, and it was acclimated to local
natural conditions.
Boomgaard (2003) looks at the adoption of various root and tuber
crops in Indonesia throughout the colonial period and examines the
chronology and reasons for progressive adoption of foreign crops –
sweet potato, Irish potato, bengkuang (yam beans), and
cassava.
The potato
was introduced in the Philippines during the late 16th century, and
to Java and China during the 17th century. It was
well-established as a crop in India by the late 18th century and in
Africa by the mid-20th century.
US and Canada
Potatoes were planted in Idaho as early as 1838; by 1900 the
state's production exceeded a million bushels. Prior to 1910, the
crops were stored in barns or root cellars, but by the 1920s potato
cellars came into use. U.S. potato production has increased
steadily; two-thirds of the crop comes from Idaho, Washington,
Oregon, Colorado, and Maine, and potato growers have strengthened
their position in both domestic and foreign markets.
By the 1960s, the Canadian Potato Research Centre in Fredericton,
New Brunswick, was one of the top six potato research institutes in
the world. Established in 1912 as a dominion experimental station,
the station began in the 1930s to concentrate on breeding new
varieties of disease-resistant potatoes. In the 1950s–60s the
growth of the french fry industry in New Brunswick led to a focus
on developing varieties for the industry. By the 1970s the
station's potato research was broader than ever before, but the
station and its research programs had changed, as emphasis was
placed on serving industry rather than potato farmers in general.
Scientists at the station even began describing their work using
engineering language rather than scientific prose.
Role in world food supply
Potato output in 2005
The United Nations
FAO reports that the world
production of potatoes in 2006 was 315 million tonnes. The annual
diet of an average global citizen in the first decade of the
twenty-first century would include about 33 kg (or 73 lb)
of potato. However, the local importance of potato is extremely
variable and rapidly changing. It remains an essential crop in
Europe (especially eastern and central Europe), where per capita
production is still the highest in the world, but the most rapid
expansion over the past few decades has occurred in southern and
eastern Asia. China is now the world's largest potato producing
country, and nearly a third of the world's potatoes are harvested
in China and India. More generally, the geographic shift of potato
production has been away from wealthier countries toward
lower-income areas of the world, although the degree of this trend
is ambiguous.
In 2008, several international organizations highlighted the
potato's role in world food production, in the face of developing
economic problems. They cited its potential derived from its status
as a cheap and plentiful crop which can be raised in a wide variety
of climates and locales. Due to perishability, only about 5% of the
world's potato crop is traded internationally; its minimal presence
in world financial markets contributed to its stable pricing during
the
2007–2008
world food price crisis. Thus, the
United Nations officially declared the year
2008 as the
International Year of the
Potato, to raise its profile in developing nations,
calling the crop a "hidden treasure". This followed the
International
Rice Year in 2004.
Nutrition
The potato contains
vitamins and
minerals that have been identified as vital
to human nutrition, as well as an assortment of
phytochemicals, such as
carotenoids and
polyphenols. A medium-sized 150 g (5.3 oz)
potato with the skin provides 27 mg of
vitamin C (45% of the Daily Value (DV)),
620 mg of
potassium (18% of DV),
0.2 mg
vitamin B6 (10% of DV) and
trace amounts of
thiamin,
riboflavin,
folate,
niacin,
magnesium,
phosphorus,
iron, and
zinc. The fiber content of a potato
with skin (2 g) is equivalent to that of many whole grain
breads,
pastas, and
cereals.
Nutritionally, the potato is best known for its
carbohydrate content (approximately 26 grams in
a medium potato). The predominant form of this carbohydrate is
starch. A small but significant portion of
this starch is resistant to digestion by
enzymes in the
stomach and
small intestine, and so reaches the
large intestine essentially intact.
This
resistant starch is considered
to have similar physiological effects and health benefits as
fiber: it provides bulk, offers
protection against
colon cancer,
improves
glucose tolerance and insulin
sensitivity, lowers plasma cholesterol and
triglyceride concentrations, increases satiety,
and possibly even reduces fat storage. The amount of resistant
starch in potatoes depends much on preparation methods. Cooking and
then cooling potatoes significantly increased resistant starch. For
example, cooked
potato starch contains
about 7% resistant starch, which increases to about 13% upon
cooling.
The nutrients of the potato seem to be fairly evenly distributed
between the flesh and the skin. For a medium potato, with and
without the skin, nutritiondata.com gives the following:
Nutrient |
Without skin (156 g) (% RDA) |
With skin (173 g) (% RDA) |
Vitamin C |
33 |
28 |
Thiamin |
11 |
7 |
Niacin |
11 |
12 |
Vitamin B6 |
23 |
27 |
Folate |
4 |
12 |
Pantothenic Acid |
9 |
7 |
Iron |
3 |
10 |
Magnesium |
10 |
12 |
Potassium |
17 |
26 |
Copper |
17 |
10 |
Dietary Fiber |
9 |
15 |
Almost all the protein content of a potato is contained in a thin
layer just under its skin.
The cooking method used can significantly impact the nutrient
availability of the potato.
Potatoes are often broadly classified as high on the
glycemic index (GI) and so are often excluded
from the diets of individuals trying to follow a
low GI diet. In fact, the GI of potatoes can
vary considerably depending on type (such as red, russet, white, or
Prince Edward), origin (where it was grown), preparation methods
(i.e., cooking method, whether it is eaten hot or cold, whether it
is mashed or cubed or consumed whole, etc), and with what it is
consumed (i.e., the addition of various high fat or high protein
toppings).
Toxicity
Seed tuber with sprouts
Early Rose variety
Potatoes contain toxic compounds known as
glycoalkaloids, of which the most prevalent
are
solanine and
chaconine. Solanine is also found in other plants
in the family
solanaceae, which includes
such plants as the deadly nightshade (
Atropa belladonna), henbane
(
Hyoscyamus niger) and
tobacco (
Nicotiana) as well as
the potato, eggplant and
tomato. This poison
affects the nervous system causing weakness and confusion.
These compounds, which protect the plant from its predators, are
generally concentrated in its leaves, stems, sprouts, and fruits.
Exposure to light, physical damage, and age increase glycoalkaloid
content within the tuber; the highest concentrations occur just
underneath the skin. Cooking at high temperatures (over 170 °C or
340 °F) partly destroys these. The concentration of glycoalkaloid
in wild potatoes suffices to produce toxic effects in humans.
Glycoalkaloids may cause
headaches,
diarrhea,
cramps and
in severe cases
coma and death; however,
poisoning from potatoes occurs very rarely. Light exposure causes
greening from
chlorophyll synthesis,
thus giving a visual clue as to areas of the tuber that may have
become more toxic; however, this does not provide a definitive
guide, as greening and glycoalkaloid accumulation can occur
independently of each other. Some varieties of potato contain
greater glycoalkaloid concentrations than others; breeders
developing new varieties test for this, and sometimes have to
discard an otherwise promising
cultivar.
Breeders try to keep solanine levels below 200 mg/kg (200
ppmw). However, when these commercial varieties turn green, even
they can approach concentrations of solanine of 1000 mg/kg
(1000 ppmw). In normal potatoes, analysis has shown solanine levels
may be as little as 3.5% of the breeders' maximum, with
7–187 mg/kg being found.
The US National Toxicology Program suggests that the average
American consumes at most 12.5 mg/day of solanine from
potatoes (the toxic dose is actually several times this, depending
on body weight). Dr. Douglas L.
Holt, the State Extension Specialist for Food
Safety at the University of Missouri, notes that no reported cases of potato-source
solanine poisoning have occurred in the U.S. in the last 50 years
and most cases involved eating green potatoes or drinking
potato-leaf tea.
Cultivation
Potatoes grown in a tall bag are
common in gardens as they increase potato yield and minimize the
amount of digging required at harvest
Correct potato husbandry can be an arduous task in some
circumstances. Good ground preparation,
harrowing,
plowing, and
rolling are always needed, along with a little grace from the
weather and a good source of water. Three successive plowings, with
associated harrowing and rolling, are desirable before planting.
Eliminating all root-weeds is desirable in potato cultivation. The
potatoes themselves are generally grown from the eyes of another
potato and not from seed. Home gardeners often plant a piece of
potato with two or three eyes in a hill of mounded soil. Commercial
growers plant potatoes as a row crop using seed tubers, young
plants or microtubers and may mound the entire row. Seed potato
crops are 'rogued' in some countries to eliminate diseased plants
or those of a different variety from the seed crop.
Potatoes are sensitive to heavy
frosts, which
damage them in the ground. Even cold weather makes potatoes more
susceptible to bruising and possibly later rotting which can
quickly ruin a large stored crop.
At harvest time, gardeners usually dig up potatoes with a
long-handled, three-prong "grape" (or graip), i.e. a
spading fork, or a potato hook which is similar
to the graip but its tines are at a 90 degree angle to the handle.
In larger plots, the plow can serve as the fastest implement for
unearthing potatoes. Commercial harvesting is typically done with
large potato harvesters which scoop up the plant and the
surrounding earth. This is transported up an apron chain consisting
of steel links several feet wide, which separates some of the dirt.
The chain deposits into an area where further separation occurs.
Different designs use different systems at this point. The most
complex designs use vine choppers and shakers, along with a blower
system or "Flying Willard" to separate the potatoes from the plant.
The result is then usually run past workers who continue to sort
out plant material, stones, and rotten potatoes before the potatoes
are continuously delivered to a wagon or truck. Further inspection
and separation occurs when the potatoes are unloaded from the field
vehicles and put into storage.
Immature potatoes may be sold as "New Potatoes" and are
particularly valued for taste. These are often harvested by the
home gardener or farmer by "grabbling", i.e. pulling out the young
tubers by hand while leaving the plant in place.
Potatoes are usually cured after harvest to improve skin-set.
Skin-set is the process by which the skin of the potato becomes
resistant to skinning damage. Potato tubers may be susceptible to
skinning at harvest and suffer skinning damage during harvest and
handling operations. Curing allows the skin to fully set and any
wounds to heal. Wound-healing prevents infection and water-loss
from the tubers during storage. Curing is normally done at
relatively warm temperatures to with high humidity and good
gas-exchange if at all possible.
Storage
Storage facilities need to be carefully designed to keep the
potatoes alive and slow the natural process of decomposition, which
involves the breakdown of starch. It is crucial that the storage
area is dark, well ventilated and for long-term storage maintained
at temperatures near . For short-term storage before cooking,
temperatures of about to are preferred. Temperatures below convert
potatoes' starch into sugar, which alters their taste and cooking
qualities and leads to higher
acrylamide
levels in the cooked product, especially in deep-fried
dishes.
Under optimum conditions possible in commercial warehouses,
potatoes can be stored for up to ten to twelve months. When stored
at homes the shelf life is usually only for several weeks. If
potatoes develop green areas or start to sprout, these areas should
be trimmed before using.
When stored commercially, Potatoes should undergo the following
storage phases –
- Equalisation or drying phase: tuber surface
moisture may need drying. Ventilation fans are run continuously to
equalize average pile temperature to within 2°C (3°F) of average
pulp temperature.
- Wound Healing, pre-conditioning phase: to at
85% to 95% RH for 15 to 30 days.
Care is taken to avoid water condensation. Higher temperatures are
sometimes used but above is avoided.
- Cooling phase: temperature is brought down by
from 4°C (7°F) to 10°C (18°F) (depending on variety) at about 0.5
to 1 °C per day. Cooling air should not be lower than 1.5 °C than
the potatoes. Efficient Air flow is maintained to provide even
cooling. A RH of 95% to 98% is
preferred.
- Holding phase: holding temperature and high
RH is maintained. Intermittent
ventilation only to control CO² build up and maintain O² levels.
Maintain potatoes at various locations within 1°C (2°F) pulp
temperature of one another.
- Reconditioning phase: warming up of the potato
from holding temperature to preferably within 5°C (9°F) of handling
temperatures to avoid condensation, handling damage, recover
color.
Varieties
Different types of potato
Organically grown Russet
Burbanks
While there are close to 4000 different varieties of potato, it has
been bred into many standard or well-known varieties, each of which
has particular agricultural or culinary attributes. Varieties are
generally categorized into a few main groups—such as russets, reds,
whites, yellows (also called Yukons) and purples—based on common
characteristics. Around 80 varieties are commercially available in
the UK. For culinary purposes, varieties are often described in
terms of their waxiness. Floury, or mealy (baking) potatoes have
more starch (20–22%) than waxy (boiling) potatoes (16–18%). The
distinction may also arises from variation in the comparative ratio
of two potato starch compounds:
amylose and
amylopectin. Amylose, a long-chain
molecule, diffuse out of the starch granule when cooked in water,
and lends itself to dishes in which the potato is mashed; varieties
containing a slightly higher amylopectin content, a highly branched
molecule, help to retain the potato its shape during boiling.
The
European
Cultivated Potato Database (ECPD) is an online collaborative
database of potato variety descriptions, updated and maintained by
the Scottish Agricultural Science Agency within the framework of
the European Cooperative Programme for Crop Genetic Resources
Networks (ECP/GR) which is organised by the International Plant
Genetic Resources Institute (IPGRI).
Popular varieties (
cultivars)
include:
- Anya
- Atlantic
- Belle de Fontenay
- BF-15
- Bintje
- Cabritas
- Camota
- Chelina
- Chiloé
- Cielo
- Clavela Blanca
- Désirée
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Genetic research has produced several
genetically modified varieties.
New
Leaf, owned by
Monsanto
Company, incorporated genes from
Bacillus thuringiensis, which
conferred resistance to the
Colorado potato beetle;
New Leaf
Plus and
New Leaf Y, approved by US regulatory
agencies during the 1990s, also included resistance to viruses.
McDonald's,
Burger
King,
Frito-Lay, and
Procter & Gamble announced that
they would not use genetically modified potatoes, and Monsanto
published its intent to discontinue the line in March 2001.
The
starch content of Amflora, waxy potato variety from the German
chemical company BASF, has been
modified to contain only amylopectin,
making it inedible but more useful for industrial purposes; as of
2007, it was close to gaining acceptance in the European Union. On 22 September 2007,
Benguet State University (BSU) announced that four
potato varieties—Igorota, Solibao, Ganza and one not yet officially
named—possess more than 18% dry matter
content required by fast-food chains to
make crispy and sturdy French
fries. Since 2005 a natural 100% amylopectine waxy
potato variety called ELIANE is being cultivated by the starch
company AVEBE.
Some horticulturists sell
chimeras, made by grafting a
tomato plant onto a potato plant, producing both edible tomatoes
and potatoes. This practice is not very widespread.
Pests
A potato ruined by late blight
The historically significant
Phytophthora infestans (late
blight) remains an ongoing problem in Europe and the United States.
Other potato diseases include
Rhizoctonia,
Sclerotinia,
Black Leg,
Powdery Mildew,
Powdery Scab,
Leafroll Virus, and
Purple Top.
Insects that commonly transmit potato diseases or damage the plants
include the
Colorado potato
beetle, the
potato tuber moth,
the green peach aphid (
Myzus
persicae), the Potato Aphid, Beetleafhoppers,
Thrips, and
Mites. The
potato root nematode is a microscopic
worm that thrives on the roots, thus causing the potato plants to
wilt. Since its eggs can survive in the soil for several years,
crop rotation is recommended.
Organic potatoes
During the crop year 2008 many of the
certified organic potatoes produced
in the United Kingdom and certified by the
Soil Association as organic were sprayed
with a
copper pesticide to control
potato blight (
Phytophthora infestans). According to the
Soil Association, the total copper that can be applied to organic
land is 6 kg/ha/year.
Culinary uses
Potatoes are prepared in many ways: skin-on or peeled, whole or cut
up, with seasonings or without. The only requirement involves
cooking to break down the starch. Most potato dishes are served
hot, but some are first cooked then served cold, notably
potato salad and
potato
chips/crisps.
Common dishes are:
mashed potatoes,
which are first boiled (usually peeled), and then mashed with
milk or
yogurt and
butter; whole
baked
potatoes;
boiled or
steamed potatoes;
French-fried potatoes or chips; cut into cubes
and
roasted;
scalloped, diced, or sliced and fried
(home fries); grated into small thin strips and fried (hash
browns); grated and formed into dumplings,
Rösti or
potato
pancakes. Unlike many foods, potatoes can also be easily cooked
in a
microwave oven and still retain
nearly all of their nutritional value, provided that they are
covered in ventilated
plastic wrap to
prevent
moisture from escaping—this method
produces a meal very similar to a steamed potato while retaining
the appearance of a conventionally baked potato. Potato chunks also
commonly appear as a
stew ingredient.
Potatoes are boiled between 10 and 25 minutes, depending on size
and type, to become soft.
Regional dishes
Latin America
Papa rellena
Peruvian Cuisine naturally contains
the potato as a primary ingredient in many dishes, as around 3,000
varieties of this tuber are grown there.Some of the more famous
dishes include
Papa a la
huancaina,
Papa rellena, Ocopa,
Carapulcra, Causa and Cau Cau among many others. French-fried
potatoes are a typical ingredient in Peruvian stir-fries, including
the classic dish
Lomo saltado.
Chuño is a freeze-dried potato product traditionally made
by Quechua and Aymara
communities of Peru and Bolivia , and is known in various countries of South
America, including Peru, Bolivia, Argentina, and Chile. In
Chile's Chiloé archipelago, potatoes are the main ingredient of
many dishes, including milcaos, chapaleles,
curanto and chochoca.
In Ecuador the potato, as well as being a staple with most
dishes, is featured in the hearty Locro de Papas, a thick
soup of potato, squash, and cheese.
Europe
Fish and chips
In the UK, potatoes form part of the traditional staple
fish and chips. Roast potatoes are commonly
served with a
Sunday roast. Mashed
potatoes also form a major component of several other traditional
dishes such as
shepherd's pie,
bubble and squeak,
champ,
bangers and
mash, and the mashed potatoes which accompany
haggis. The
Tattie scone
is another popular Scottish dish containing potatoes. Potatoes are
also often
sautéed to accompany a meal.
In the UK, new potatoes are typically cooked with
mint and served with a little melted butter;
Jersey Royal potatoes are the most
prized new potatoes, and have their own
Protected Designation of
Origin.
In Ireland,
Colcannon is a traditional
Irish dish involving mashed potato combined with shredded cabbage
and onion.
Boxty pancakes are eaten all over
Ireland, although associated especially with the north, and in
Irish diaspora communities: they are traditionally made with grated
potatoes, soaked to loosen the starch and mixed with flour,
buttermilk and baking powder.
A variant eaten and sold in Lancashire, especially Liverpool, is made with cooked and mashed
potatoes.
Bryndzové halušky is the
Slovakian national dish, made of a batter of flour and finely
grated potatoes that is boiled to form dumplings. These are
then mixed with regionally varying ingredients.
In
Northern and Eastern Europe, especially in Scandinavian countries, Poland, Russia, Belarus and Ukraine, newly harvested, early ripening varieties are
considered a special delicacy. Boiled whole and served with
dill, these "new potatoes" are traditionally
consumed together with
Baltic
herring. Puddings made from grated potatoes (
kugel,
kugelis, and
potato babka) are popular items of
Ashkenazi,
Lithuanian, and
Belarussian cuisine.
A baked potato served with
butter
In
Western Europe, especially in
Belgium, sliced potatoes are fried to create
frieten, the
original
French fried
potatoes.
Stamppot, a
traditional Dutch meal, is
based on mashed potatoes mixed with vegetables.
In France, the most famous potato dish is the
Hachis Parmentier, named after
Antoine-Augustin
Parmentier, a French pharmacist, nutritionist, and agronomist
who, in the late 18th century, was instrumental in the acceptance
of the potato as an edible crop in the country.
The Pâté aux pommes de
terre is a regional potato dish from the central Allier and Limousin regions.
In the
north of Italy, particularly in the Friuli region of
the northeast, potatoes serve to make a type of pasta called
gnocchi. Similarly, cooked and
mashed potatoes or potato flour can be used in the knödel or dumpling eaten
with or added to meat dishes all over central and Eastern Europe,
but especially in Bavaria and Luxembourg. Potatoes form one of the main ingredients
in many soups such as the
vichyssoise
and Albanian potato and cabbage soup. In western Norway,
komle is popular.
A
traditional Canary
Islands dish is Canarian wrinkly potatoes or
Papas arrugadas. Tortilla de patatas (potato
omelete) and
Patatas bravas (a dish of fried potatoes in a
spicy tomato sauce) are near-universal constituent of Spanish
tapas.
North America
French fries served with a
hamburger
Poutine: Fried potatoes, cheese curds,
and gravy
In the United States, potatoes have become one of the most widely
consumed crops and thus have a variety of preparation methods and
condiments.
French fries and often
hash browns are commonly found in
typical American fast-food burger joints and cafeterias.
One
popular favorite involves a baked potato with cheddar cheese (or
sour cream and chives) on top, and in New England "smashed potatoes" (a chunkier variation on mashed
potatoes, retaining the peel) have great popularity. Potato
flakes are popular as an instant variety of mashed potatoes, which
reconstitute into mashed potatoes by adding water, with butter or
oil and salt to taste. A regional dish of
Central New York,
salt potatoes are bite-sized new potatoes
boiled in water saturated with salt then served with melted butter.
At more formal dinners, a common practice includes taking small red
potatoes, slicing them, and roasting them in an iron skillet. Among
American Jews, the practice of eating
latkes (fried potato pancakes) is common
during the festival of
Hanukkah.
A
traditional Acadian dish from New Brunswick is known as poutine râpée. The
Acadian poutine is a ball of grated and
mashed potato, salted, sometimes filled with
pork in the center, and boiled. The result is a
moist ball about the size of a
baseball. It is commonly eaten with salt and
pepper or
brown sugar. It is believed to
have originated from the German
Klöße, prepared by early German
settlers who lived among the Acadians.
Poutine, by contrast, is a hearty
serving of french fries, fresh
cheese
curds and hot gravy.
Tracing its origins to Quebec in the
1950s, it has become a widespread and popular dish throughout
Canada.
Indian Subcontinent
In India, the most popular potato dishes are aloo ki sabzi, and
samosa, which is spicy mashed potato mixed
with a small amount of vegetable stuffed in conical dough, and deep
fried. Potatoes are also a major ingredient as fast food items,
such as aloo chaat, where they are deep fried and served with
chutney. In Northern India, alu dum and alu paratha are a favorite
part of the diet: the first is a spicy curry of boiled potato, the
second is a type of stuffed chapati.
A dish called Masala Dosa from South India is very famous all over
India. It is a thin pancake of rice and pulse paste rolled over
spicy smashed potato and eaten with sambhar and chutney.Other
favorite dishes are Alu Tikki, pakoda items etc.
Vada pav is a popular vegetarian fast food
dish in Mumbai and other regions in the Maharashtra in India.
East Asia
In East Asia, rice still dominates the potato, especially in China
and Japan. However, it is occasionally seen in Korean and Thai
cuisines.
Other uses
- Potatoes are also used to brew alcoholic beverages such as
vodka, and potcheen.
As well as food for domestic animals.
- Potato starch is used in the food
industry as for example thickener and binder of soups and sauces,
in the textile industry, as adhesive, and for the manufacturing of
papers and boards.
- Maine companies
are exploring the possibilities of using waste potatoes to obtain
polylactic acid for use in plastic
products; other research projects seek ways to use the starch as a
base for biodegradable
packaging.
In art
The potato has been an essential crop in the
Andes since the
pre-Columbian Era.
The Moche culture from Northern Peru made
ceramics from earth, water, and fire. This pottery was a
sacred substance, formed in significant shapes and used to
represent important themes. Potatoes are represented
anthropomorphically as well as naturally.
During the late 19th century, numerous images of potato harvesting
appeared in European art, including the works of
Willem Witsen and
Anton
Mauve.
Van Gogh's 1885 painting
"
The Potato Eaters" portrays a
family eating potatoes.
Invented in 1949 and marketed and sold commercially by
Hasbro in 1952,
Mr. Potato
Head is an American toy consisting of a plastic model of a
potato which can be decorated with a variety of attachable plastic
parts such as ears and eyes to make a face. It was the first toy
ever advertised on television.
There is
an Idaho Potato Museum in
Blackfoot,
Idaho.
See also
Notes
- Potato storage, value Preservation:
- Lay summary
- Real Academia Española. Diccionario Usual
- Chilean Tetraploid Cultivated Potato, Solanum
tuberosum is Distinct from the Andean Populations:
Microsatellite Data, Celeste M. Raker and David M. Spooner,
Univewrsity of Wisconsin, published in Crop Science,
Vol.42, 2002
- Electronic Journal of Biotechnology – Molecular
description and similarity relationships among native germplasm
potatoes (Solanum tuberosum ssp. tuberosum L.) using
morphological data and AFLP markers
- Gene RB cloned from Solanum bulbocastanum confers
broad spectrum resistance to potato late blight, Junqi Song et al.,
PNAS 2003
- The yield of Calories per acre (about 9.2 million) is higher
than that of maize (7.5
million), rice (7.4 million),
wheat (3 million), or
soybean (2.8
million).
- Lay summary
- Office of International Affairs, Lost Crops of the Incas:
Little-Known Plants of the Andes with Promise for Worldwide
Cultivation (1989) online
- John Reader, John. Propitious Esculent: The Potato in World
History (2008)
- William H. McNeill, "How the Potato Changed the World's
History." Social Research 1999 66(1): 67–83.
- John Reader, Propitious Esculent: The Potato in World
History (2008)
- von Bremzen, p. 322
- Economist.com Llamas and mash
- International year of the potato website
- William L. Langer, "American Foods and Europe's Population
Growth 1750–1850," Journal of Social History, 8#2 (1975),
pp. 51–66
- John Komlos, "The New World's Contribution to Food Consumption
During the Industrial Revolution." Journal of European Economic
History 1998 27(1): 67–82. Issn: 0391-5115
- John Reader, John. Propitious Esculent: The Potato in World
History (2008)
- Dorien Knaap, The W.A. Scholtencompany: the first Dutch
industrial multinational, Summery of dissertation, University of
Groningen, 2004 [1]
- William H. McNeill, "The Introduction of the Potato into
Ireland," Journal of Modern History 21 (1948): 218–21.
in
JSTOR
- Cormac Ó Gráda, Black '47 and Beyond: The Great Irish
Famine in History, Economy, and Memory. (1999).
- Cormac Ó Gráda, et al. When the Potato Failed: Causes and
Effects of the Last European Subsistence Crisis, 1845–1850.
(2007)
- Steven Turner, and Heather Molyneaux, "Agricultural Science,
Potato Breeding and the Fredericton Experimental Station, 1912–66."
Acadiensis 2004 33(2): 44–67. Issn: 0044-5851
- As other staples soar, potatoes break new
ground By Terry Wade, Reuters, 15 April 2008.
- Khaleej Times Online – UN launches Int'national
Year of the Potato
- 'Humble' Potato Emerging as World's next Food Source, p.
20
- Cummings JH, Beatty ER, Kingman SM, Bingham SA, Englyst HN.
Digestion and physiological properties of resistant starch in the
human large bowel. Br J Nutr. 1996;75:733-47.
- Hylla S, Gostner A, Dusel G, Anger H, Bartram HP, Christl SU,
Kasper H, Scheppach W. Effects of resistant starch on the colon in
healthy volunteers: possible implications for cancer prevention. Am
J Clin Nutr. 1998;67:136-42
- Raban A, Tagliabue A, Christensen NJ, Madsen J, Host JJ, Astrup
A. Resistant starch: the effect on postprandial glycemia, hormonal
response, and satiety. Am J Clin Nutr. 1994;60:544–551.
- Nutritiondata.com
- Nutritiondata.com
- Glycoalkaloid and calystegine contents of eight potato
cultivars J-Agric-Food-Chem. 2003 May 7; 51(10):
2964–73
- Kleinkopf G.E. and N. Olsen. 2003. Storage Management, in:
Potato Production Systems, J.C. Stark and S.L. Love (eds),
University of Idaho Agricultural Communications, 363–381.
- "Potato storage and care" – Healthy
Potato.com
- Europotato.org
- Papas Nativas de Chiloé – Descripción de
tuberculos
- Inquirer.net, RP's new potato varieties good for
French fries
- Section 4.11.11, page 103 Soil Association Organic Standards for Producer,
Verion 16, January, 2009
- "Thousands of tons of organic food produced using
toxic chemicals" article by David Derbyshire in
The Daily
Mail 1 January 2008
- Links to forms permitting application of copper
fungicide on the website of the Soil Association
- Swegro
- Peru Celebrates Potato Diversity
- Timothy Johns: With bitter Herbs They Shall Eat it : Chemical
ecology and the origins of human diet and medicine, The University
of Arizona Press, Tucson 1990, ISBN 0-8165-1023-7, p. 82-84
- Berrin, Katherine & Larco Museum. The Spirit of Ancient
Peru:Treasures from the Museo Arqueológico Rafael Larco Herrera.
New York:Thames and Hudson, 1997.
- “The Tater Temple,” Via Magazine, July 2000
References
- Economist. "Llamas and mash," The Economist 28 Feb 2008 online
- Economist. "The potato: Spud we like," (leader)
The Economist 28 Feb 2008 online
- Boomgaard, Peter. "In the Shadow of Rice: Roots and Tubers in
Indonesian History, 1500–1950." Agricultural History 2003
77(4): 582–610. Issn: 0002-1482 Fulltext: Ebsco
- Hawkes, J.G. (1990). The Potato: Evolution, Biodiversity
& Genetic Resources, Smithsonian Institution Press,
Washington, D.C.
- Lang, James (2001). Notes of a Potato Watcher, Texas
A&M University, College Station, TX.
- Langer, William L. "American Foods and Europe's Population
Growth 1750–1850," Journal of Social History, Vol. 8, No.
2 (Winter, 1975), pp. 51–66 in
JSTOR
- McNeill, William H. "How the Potato Changed the World's
History." Social Research 1999 66(1): 67–83. Issn:
0037-783x Fulltext: Ebsco, by a leading
historian
- McNeill, William H. "The Introduction of the Potato into
Ireland," Journal of Modern History 21 (1948): 218–21.
in
JSTOR
- Ó Gráda, Cormac. Black '47 and Beyond: The Great Irish
Famine in History, Economy, and Memory. (1999). 272 pp.
- Ó Gráda, Cormac, Richard Paping, and Eric Vanhaute, eds.
When the Potato Failed: Causes and Effects of the Last European
Subsistence Crisis, 1845–1850. (2007). 342 pp. ISBN
978-2-503-51985-2. 15 essays by scholars looking at Ireland and all
of Europe
- Reader, John. Propitious Esculent: The Potato in World
History (2008), 315pp a standard scholarly history
- Salaman, Redcliffe N. (1989). The History and Social
Influence of the Potato, Cambridge University Press
(originally published in 1949; reprinted 1985 with new introduction
and corrections by J.G. Hawkes).
- Stevenson, W.R., Loria, R., Franc, G.D., and Weingartner, D.P.
(2001) Compendium of Potato Diseases, 2nd ed, Amer.
Phytopathological Society, St. Paul, MN.
- Zuckerman, Larry. The Potato: How the Humble Spud Rescued
the Western World. (1998). 304 pp. Douglas & McIntyre.
ISBN 0-86547-578-4.
Further reading
- The World Potato Atlas at Cgiar.org, released by the International Potato Center
in 2006 and regularly updated. Includes current chapters of 15
countries:
- South America: (English and Spanish): Bolivia, Colombia,
Ecuador, Peru
- Africa: Cameroon, Ethiopia, Kenya
- Eurasia: Armenia, Bangladesh, China, India, Myanmar, Nepal,
Pakistan, Tajikistan
- 38 others as brief "archive" chapters
- Further information links at Cgiar.org.
- World Geography of the Potato at UGA.edu,
released in 1993.
- Reference for potato history: The Vegetable Ingredients
Cookbook by Christine Ingram, Lorenz Books, 1996 ISBN
1-85967-264-7
- The History and Social Influence of the Potato by
Redcliffe N. Salaman ISBN 0-521-31623-5
- Hamilton, Andy & Dave, (2004), Potatoes – Solanum tuberosums retrieved on 4 May
2005
- Gauldie, Enid (1981). The Scottish Miller 1700 – 1900. Pub.
John Donald. ISBN 0-85976-067-7.
External links