Culinary sugars Biochemists regard sugars as relatively simple
carbohydrates. Sugars include
monosaccharides,
disaccharides, trisaccharides and the oligosaccharides - containing 1, 2, 3, and 4 or more monosaccharide units respectively. Sugars contain either
aldehyde groups (-CHO) or
ketone groups (C=O), where there are
carbon-oxygen double bonds, making the sugars reactive. Most sugars conform to (CH
2O)
n where n is between 3 and 7. A notable exception,
deoxyribose, as its name suggests, has a "missing" oxygen atom. As well as being classified by their reactive group, sugars are also classified by the number of carbons they contain. Derivatives of trioses (C
3H
6O
3) are intermediates in
glycolysis. Pentoses (5 carbon sugars) include
ribose and deoxyribose, which are present in
nucleic acids. Ribose is also a component of several chemicals that are important to the metabolic process, including
NADH and
ATP. Hexoses (6 carbon sugars) include glucose which is a universal substrate for the production of energy in the form of ATP. Through
photosynthesis plants produce glucose, which has the formula C6H12O6, and then convert it for storage as an energy reserve in the form of other carbohydrates such as
starch, or (as in cane and beet) as sucrose.
Many pentoses and hexoses can form
ring structures. In these closed-chain forms, the aldehyde or ketone group is not free, so many of the reactions typical of these groups cannot occur. Glucose in solution exists mostly in the ring form at
equilibrium, with less than 0.1% of the molecules in the open-chain form.
Monosaccharides in a closed-chain form can form
glycosidic bonds with other monosaccharides, creating disaccharides (such as sucrose) and polysaccharides (such as starch).
Enzymes must
hydrolyse or otherwise break these glycosidic bonds before such compounds will
metabolise. After digestion and absorption the principal monosaccharides present in the blood and internal tissues are: glucose, fructose, and galactose.
The prefix "glyco-" indicates the presence of a sugar in an otherwise non-carbohydrate substance. Note for example
glycoproteins, proteins to which one or more sugars are connected.
Simple sugars include
fructose,
glucose,
galactose,
maltose,
lactose and
mannose. Disaccharides occur most commonly as sucrose (cane or beet sugar - made from one glucose and one fructose), lactose (milk sugar - made from one glucose and one galactose) and maltose (made of two glucoses). These disaccharides have the formula C
12H
22O
11.
Hydrolysis can convert sucrose into a syrup of fructose and glucose, producing
invert sugar. This resulting syrup is sweeter than the original sucrose, and is useful for making confections because it does not crystalize as easily and thus produces a smoother finished product.
Chemistry Sugarcane, a tropical grass, probably originated in
New Guinea. During
prehistoric times its culture spread throughout the
Pacific Islands and into
India. By 200 BC producers in China had begun to grow it too. Westerners learned of sugarcane in the course of military expeditions into India.
Nearchos, one of Alexander the Great's commanders, described it as "a reed that gives honey without bees".
Originally, people chewed the cane raw to extract its sweetness. The process of making sugar by evaporating juice from
sugarcane developed in
India around 500 BC. In South Asia, the
Middle East and
China, sugar became a staple of cooking and
desserts.
Early refining methods involved grinding or pounding the cane in order to extract the juice, and then boiling down the juice or drying it in the sun to yield sugary solids that resembled gravel. The Sanskrit word for "sugar" (
sharkara), also means "gravel". Similarly, the
Chinese use the term "gravel sugar" (
Traditional Chinese: 砂糖) for table sugar.
History The Arabs and Berbers introduced sugar to Western Europe when they conquered the Iberian peninsula in the 8th century AD.
Crusaders also brought sugar home with them after their campaigns in the
Holy Land, where they encountered caravans carrying "sweet salt". Crusade chronicler
William of Tyre described sugar as "very necessary for the use and health of mankind."
The 1390s saw the development of a better press, which doubled the juice obtained from the cane. This permitted economic expansion of sugar plantations to
Andalucia and to the
Algarve. The 1420s saw sugar-production extended to the
Canary Islands,
Madeira and the
Azores.
In August 1492
Christopher Columbus stopped at
Gomera in the
Canary Islands, for wine and water, intending to stay only four days. He became romantically involved with the Governor of the island, Beatrice de Bobadilla, and stayed a month. When he finally sailed she gave him cuttings of sugarcane, which became the first to reach the New World.
The Portuguese took sugar to
Brazil.
Hans Staden, published in 1555, writes that by 1540
Santa Catalina Island had 800 sugar-mills and that the north coast of Brazil,
Demarara and
Surinam had another 2000. Approximately 3000 small mills built before 1550 in the New World created an unprecedented demand for
cast iron gears, levers, axles and other implements. Specialist trades in mold making and iron casting were inevitably created in Europe by the expansion of sugar. Sugar mill construction is the missing link of the technological skills needed for the
Industrial Revolution that is recognized as beginning in the first part of the 1600s.
After 1625 the
Dutch carried sugarcane from South America to the Caribbean islands — from
Barbados to the
Virgin Islands. The years 1625 to 1750 saw sugar become worth its weight in gold. Prices declined slowly as production became multi-sourced, especially through British colonial policy. Sugar-production increased in mainland North American colonies, in
Cuba, and in
Brazil. African
slaves became the dominant plantation-workers as they proved resistant to the diseases of
malaria and
yellow fever. (European
indentured servants remained in shorter supply, susceptible to disease and overall forming a less economic investment. European diseases such as
smallpox had reduced the numbers of local
Native Americans.) But replacement of Native American with African slaves also occurred because of the high death-rates on sugar-plantations. The British West Indies imported almost 4 million slaves, but had only 400 000 Blacks left after slavery ended.
With the
European colonization of the Americas, the
Caribbean became the world's largest source of sugar. These islands could supply sugar-cane using slave-labor and produce sugar at prices vastly lower than those of cane sugar imported from the East. Thus the economies of entire islands such as
Guadaloupe and
Barbados became based on sugar-production. By 1750 the French colony known as
Saint-Domingue (subsequently the independent country of
Haiti) became the largest sugar-producer in the world.
Jamaica too became a major producer in the 18th century.
Sugar-plantations fueled a demand for manpower; between 1701 and 1810 ships brought nearly one million slaves to work in Jamaica and in
Barbados.
During the eighteenth century, sugar became enormously popular and the sugar-market went through a series of
booms. The heightened demand and production of sugar came about to a large extent due to a great change in the eating habits of many Europeans. For example, they began consuming
jams,
candy, tea, coffee, cocoa, processed foods, and other sweet victuals in much greater numbers. Reacting to this increasing craze, the islands took advantage of the situation and began harvesting sugar in extreme amounts. In fact, they produced up to ninety percent of the sugar that the western Europeans consumed. Of course some islands were more successful than others when it came to producing the product. For instance, Barbados and the British Leewards can be said to have been the most successful in the production of sugar because it counted for 93% and 97% respectively of each island's exports.
Planters later began developing ways to boost production even more. For example, they began using more
manure when growing their crops. They also developed more advanced mills and began using better types of sugar-cane. Despite these and other improvements, the price of sugar reached soaring heights, especially during events such as the revolt against the Dutch and the
Napoleonic Wars. Sugar remained in high demand, and the islands' planters knew exactly how to take advantage of the situation.
As Europeans established sugar-plantations on the larger Caribbean islands, prices fell, especially in
Britain. By the
eighteenth century all levels of society had become common consumers of the former luxury product. At first most sugar in Britain went into tea, but later
confectionery and
chocolates became extremely popular. Suppliers commonly sold sugar in solid cones and consumers required a
sugar nip, a pliers-like tool, to break off pieces.
Sugar-cane quickly exhausts the
soil in which it grows, and planters pressed larger islands with fresher soil into production in the nineteenth century. In this century, for example, Cuba rose to become the richest land in the Caribbean (with sugar as its dominant crop) because it had the only major island land-mass free of mountainous terrain. Instead, nearly three-quarters of its land formed a rolling plain — ideal for planting crops. Cuba also prospered above other islands because Cubans used better methods when harvesting the sugar crops: they adopted modern milling-methods such as water-mills, enclosed furnaces, steam-engines, and vacuum-pans. All these technologies increased productivity.
After the
Haïtian Revolution established the independent state of
Haiti, sugar production in that country declined and
Cuba replaced Saint-Domingue as the world's largest producer.
Long established in
Brazil, sugar-production spread to other parts of
South America, as well as to newer European colonies in
Africa and in the Pacific, where it became especially important in
Fiji. In Colombia, the planting of sugar started very early on, and entrepreneurs imported many African slaves to cultivate the fields. The industrialization of the Colombian industry started in 1901 with the establishment of the first steam-powered sugar mill by
Santiago Eder.
Cane sugar outside Asia In 1747 the German chemist
Andreas Marggraf identified sucrose in
beet root. This discovery remained a mere curiosity for some time, but eventually Marggraf's student
Franz Achard built a sugarbeet-processing factory at
Cunern in
Silesia, under the patronage of King
Frederick William III of Prussia (reigned 1797 - 1840). While never profitable, this plant operated from 1801 until it suffered destruction during the
Napoleonic Wars (ca 1802 - 1815).
Napoleon, cut off from Caribbean imports by a British
blockade and at any rate not wanting to fund British merchants, banned sugar imports in 1813. The beet-sugar industry that emerged in consequence grew, and today, sugar-beet provides approximately 30% of world sugar production.
While no longer grown by slaves, sugar from developing countries has an on-going association with workers earning minimal wages and living in extreme poverty.
In the developed countries, the sugar industry relies on machinery, with a low requirement for manpower. A large beet-refinery producing around 1,500 tonnes of sugar a day needs a permanent workforce of about 150 for 24-hour production.
The rise of beet sugar Beginning in the late 18th century, sugar production became increasingly mechanized. The
steam engine first powered a sugar mill in
Jamaica in
1768, and soon thereafter, steam replaced direct firing as the source of process heat.
In 1813 the
British chemist
Edward Charles Howard invented a method of refining sugar that involved boiling the cane juice not in an open kettle, but in a closed vessel heated by steam and held under partial vacuum. At reduced pressure, water boils at a lower temperature, and this development both saved fuel and reduced the amount of sugar lost through
caramelization. Further gains in fuel efficiency came from the
multiple-effect evaporator, designed by the
African-American engineer
Norbert Rillieux perhaps as early as the 1820s, although the first working model dates from 1845. This system consisted of a series of vacuum pans, each held at a lower pressure than the previous one. The vapors from each pan were used to heat the next, and little heat wasted. Today, multiple-effect evaporators are employed widely in many industries for evaporating water.
The process of separating the sugar from the molasses also received mechanical attention: David Weston first applied the centrifuge to this task in
Hawaii in 1852.
Mechanization See also
International Commission for Uniform Methods of Sugar Analysis Measuring sugar Scientists use degrees
Brix (symbol °Bx), introduced by
Antoine Brix, as units of measurement of the mass ratio of dissolved substance to water in a liquid. A 25 °Bx sucrose solution has 25 grams of sucrose sugar per 100 grams of liquid. Or, to put it another way, 25 grams of sucrose sugar and 75 grams of water exist in the 100 grams of solution.
An infrared Brix sensor measures the vibrational frequency of the sugar molecules, giving a Brix degrees measurement. This does not equate to Brix degrees from a density or refractive index measurement because it will specifically measure dissolved sugar concentration instead of all dissolved solids. When using a refractometer, one should report the result as "refractometric dried substance" (RDS). One might speak of a liquid as having 20 °Bx RDS. This refers to a measure of percent by weight of
total dried solids and, although not technically the same as Brix degrees determined through an infrared method, renders an accurate measurement of sucrose content, since sucrose in fact forms the majority of dried solids. The advent of in-line infrared Brix measurement sensors has made measuring the amount of dissolved sugar in products economical using a direct measurement.
Dissolved sugar content Technicians usually measure the purity of sugar, i.e. the sucrose content, by
polarimetry — the measurement of the rotation of plane-polarized light by a solution of sugar.
Sugar purity Historically one of the most widely-traded commodities in the world, sugar accounts for around 2% of the global dry cargo market. International sugar prices show great volatility, ranging from around 3 to over 60 cents per pound in the
past 50 years. Of the world's 180-odd countries, around 100 produce sugar from beet or cane, a few more refine raw sugar to produce white sugar, and all countries consume sugar. Consumption of sugar ranges from around 3 kilogrammes per person per annum in Ethiopia to around 40 kg/person/yr in Belgium. Consumption per capita rises with income per capita until it reaches a plateau of around 35kg per person per year in middle-income countries.
Many countries subsidize sugar-production heavily. The European Union, the United States, Japan and many developing countries subsidize domestic production and maintain high tariffs on imports. Sugar prices in these countries have often exceeded prices on the international market by up to three times;
today, with world market sugar futures prices
currently strong, such prices typically exceed world prices by two times.
Within international trade bodies, especially in the
World Trade Organization, the "
G20" countries led by Brazil have long argued that because these sugar markets essentially exclude cane-sugar imports, the G20 sugar-producers receive lower prices than they would under
free trade. While both the
European Union and United States maintain trade agreements whereby certain developing and
less-developed countries (LDCs) can sell certain quantities of sugar into their markets, free of the usual import tariffs, countries outside these preferred trade régimes have complained that these arrangements violate the "
most favoured nation" principle of international trade.
In 2004, the
WTO sided with a group of cane-sugar exporting nations (led by Brazil and Australia) and ruled the EU sugar-régime and the accompanying ACP-EU Sugar Protocol (whereby a group of African, Caribbean, and Pacific countries receive preferential access to the European sugar market) illegal. In response to this and to other rulings of the WTO, and owing to internal pressures on the EU sugar regime, the European Commission proposed on
22 June 2005 a radical reform of the EU sugar régime, cutting prices by 39% and eliminating all EU sugar exports. The African, Caribbean, Pacific and
least developed country sugar-exporters reacted with dismay to the EU sugar proposals, arguing for a fairer reform of the EU régime which would foster development and contribute meaningfully to the achievement of the
Millennium Development Goals. On
25 November 2005 the Council of the EU agreed to cut EU sugar prices by 36% as from 2009. It now seems
Small quantities of sugar, especially specialty grades of sugar, reach the market as '
fair trade' commodities; the fair-trade system produces and sells these products with the understanding that a larger-than-usual fraction of the revenue will support small farmers in the developing world. However, whilst the Fairtrade Foundation offers a premium of USD 60.00 per tonne to small farmers for sugar branded as "Fairtrade", government schemes such the U.S. Sugar Program and the
ACP Sugar Protocol offer premiums of around USD 400.00 per tonne above world market prices.
Sugar economics Biobutanol Brown sugar Brix Palm sugar Caramel Corn syrup Fermentation Glycomics Golden syrup Holing cane Natural brown sugar Stevia, a herb many times sweeter than pure sugar
Sugar plantations in the Caribbean Sugar loaf Sugar substitute List of unrefined sweeteners Rock candy Barley sugar See also History and culture Cook's Thesaurus: Sugar (www.foodsubs.com)
Food Expert Report on diet and chronic disease (WHO/FAO)
Center for Science in the Public Interest sugar-labeling campaign Health Ethical Sugar NGO The politics of sugar Harvesting Poverty: America's Sugar Daddies Social and environmental Wide range of information about sugars, from the Canadian Sugar Institute, a non-profit trade association of Canada's manufacturers of refined sugar Least Developed Countries sugar site African, Caribbean and Pacific sugar exporters Sugar Traders Association of the UK European Union sugar-régime proposals WTO ruling on the EU sugar-régime U.S. Sugar Import Program Sugar Association of London Sugar Statistics at Chronos Shipping website Sample trade-sugars Trade "The Myth of the Sugar Buzz" article from Skepticism.Net
Chemical A C Hannah,
The International Sugar Trade,
ISBN 1-85573-069-3 William Dufty,
Sugar Blues,
ISBN 0-446-34312-9
Beet
1 comment:
Nice post !! Thanks for sharing with us. If anyone required industrial gears then come to Ashoka Group, the India's leading gears manufacturers and gears suppliers. Here you will get all type of quality gears at competitive rates. We serves industrial gears to almost every industries.
Post a Comment