Sugar

This article is about sugar as food and as an important and widely-traded commodity. For other uses, see Sugar (disambiguation).

Magnification of grains of sugar, showing their monoclinic hemihedral crystalline structure.

Sugar, granulated

Nutritional value per 100 g (3.5 oz)
Energy	1,619 kJ (387 kcal)
Carbohydrates	99.98 g
Sugars	99.91 g
Dietary fiber	0 g
Fat	0 g
Protein	0 g
Vitamins	Quantity %DV†
Riboflavin (B2)	1% 0.019 mg
Minerals	Quantity %DV†
Calcium	0% 1 mg
Iron	0% 0.01 mg
Potassium	0% 2 mg
Other constituents	Quantity
Water	0.03 g
†Percentages estimated using US recommendations for adults, except for potassium, which is estimated based on expert recommendation from the National Academies.

Sugars, brown

Nutritional value per 100 g (3.5 oz)
Energy	1,576 kJ (377 kcal)
Carbohydrates	97.33 g
Sugars	96.21 g
Dietary fiber	0 g
Fat	0 g
Protein	0 g
Vitamins	Quantity %DV†
Thiamine (B1)	1% 0.008 mg
Riboflavin (B2)	1% 0.007 mg
Niacin (B3)	1% 0.082 mg
Vitamin B6	2% 0.026 mg
Folate (B9)	0% 1 μg
Minerals	Quantity %DV†
Calcium	7% 85 mg
Iron	11% 1.91 mg
Magnesium	7% 29 mg
Phosphorus	2% 22 mg
Potassium	12% 346 mg
Sodium	2% 39 mg
Zinc	2% 0.18 mg
Other constituents	Quantity
Water	1.77 g
†Percentages estimated using US recommendations for adults, except for potassium, which is estimated based on expert recommendation from the National Academies.

Magnified crystals of refined sugar.

Sugar, (the word stems from the Sanskrit sharkara) consists of a class of edible crystalline substances including sucrose, lactose, and fructose. Human taste-buds interpret its flavor as sweet. Sugar as a basic food carbohydrate primarily comes from sugar cane and from sugar beet, but also appears in sorghum, as sugar maple (in maple syrup), and from many other sources. It forms the main ingredient in much candy. Some claim that excessive consumption of sugar correlates with damage to one's teeth and with obesity.

Terminology

Popular

In non-scientific use, the term sugar refers to sucrose (also called "table sugar" or "saccharose") — a white crystalline solid disaccharide. In this informal sense, the word "sugar" principally refers to crystalline sugars.

Humans most commonly use sucrose as their sugar of choice for altering the flavor and properties (such as mouthfeel, preservation, and texture) of beverages and food. Commercially-produced table-sugar comes either from sugar cane or from sugar beet. Manufacturing and preparing food may involve other sugars, including palm sugar and fructose, generally obtained from corn (maize) or from fruit.

Sugar may dissolve in water to form a syrup. A great many foods exist which principally contain dissolved sugar. Generically known as "syrups", they may also have other more specific names such as "honey" or "molasses".

Scientific

Scientifically, sugar refers to any monosaccharide or disaccharide. Monosaccharides (also called "simple sugars"), such as glucose, store chemical energy which biological cells convert to other types of energy.

In a list of ingredients, any word that ends with "ose" will likely denote a sugar. Sometimes such words may also refer to any types of carbohydrates soluble in water.

Glucose (a type of sugar found in human blood-plasma) has the molecular formula C₆ H₁₂ O₆.

Culinary/nutritional

In culinary terms, the foodstuff known as sugar delivers a primary taste sensation of sweetness. Apart from the many forms of sugar and of sugar-containing foodstuffs, alternative non-sugar-based sweeteners exist, and these particularly attract interest from people who have problems with their blood-sugar level (such as diabetics) and people who wish to limit their calorie-intake while still enjoying sweet foods. Both natural and synthetic substitutes exist with no significant carbohydrate (and thus low-calorie) content: for instance stevia (a herb), and saccharin (produced from naturally occurring but not necessarily naturally edible substances by inducing appropriate chemical reactions).

History

Early use of sugar-cane in Asia

Originally, people chewed the cane raw to extract its sweetness. The Indians discovered how to crystallize sugar during the Gupta dynasty, around 350 AD. John F. Robyt (1998) locates the two most probable origins of sugar cultivation as North East India or the South Pacific, which provide evidence of sugarcane cultivation as early as 10,000 BC and 6,000 BC respectively. Further archaeological evidence associates sugar with the Indus valley.

This cultivation spread to the Indian subcontinent during early antiquity. Sugar culture spread from India to China, and from China it spread even further. However, sugar remained relatively unimportant until the Indians discovered methods of turning sugarcane juice into granulated crystals which would prove easier to store and to transport. Indian sailors, consumers of clarified butter and sugar, spread this food through various trade routes. In South Asia, the Middle East and China, sugar became a staple of cooking and desserts.

Some evidence suggests that the Greeks under Alexander the Great may have taken sugar from India during their retreat. It would later spread to Europe and to Africa.

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 looked like 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.

Cane sugar outside Asia

A sugar-cane cutter in Cuba.

During the Muslim Agricultural Revolution, Arab entrepreneurs adopted the techniques of sugar production from India and then refined and transformed them into a large-scale industry. Arabs set up the first sugar mills, refineries, factories and plantations. The Arabs and Berbers diffused sugar throughout the Arab Empire and beyond across much of the Old World, including Western Europe after they conquered the Iberian Peninsula in the 8th century AD. Crusaders also brought sugar home with them to Europe after their campaigns in the Holy Land, where they encountered caravans carrying "sweet salt". Crusade chronicler William of Tyre, writing in the late 12th century, 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 sugar-cane, 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 developed in Europe due to the expansion of sugar-production. Sugar-mill construction developed technological skills needed for a nascent industrial revolution in the early 17th-century.

After 1625 the Dutch carried sugar-cane from South America to the Caribbean islands — where it became grown from Barbados to the Virgin Islands. The years 1625 to 1750 saw sugar become worth its weight in gold. Contemporaries often compared the worth of sugar with valuable commodities including musk, pearls, and spices. Prices declined slowly as production became multi-sourced, especially through British colonial policy. Formerly an indulgence of the rich, sugar became increasingly common among the poor. Sugar-production increased in mainland North American colonies, in Cuba, and in Brazil. African slaves became the dominant source of 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 in the British Empire in 1838.

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 producing more sugar. In fact, they produced up to ninety percent of the sugar that the western Europeans consumed. Some islands proved more successful than others when it came to producing the product. And in Barbados and the British Leeward Islands sugar provided 93% and 97% respectively of 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. Many Britons (especially children) also ate jams. 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 formed 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.

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.

The rise of beet sugar

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 (in present-day Poland), 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 imports of sugar in 1813. The beet-sugar industry that emerged in consequence grew, and today sugar-beet provides approximately 30% of world sugar production.

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.

Mechanization

Beginning in the late 18th century, the production of sugar became increasingly mechanized. The steam engine first powered a sugar-mill in Jamaica in 1768, and soon after, 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 served to heat the next, with minimal heat wasted. Today, many industries use multiple-effect evaporators for evaporating water.

The process of separating sugar from molasses also received mechanical attention: David Weston first applied the centrifuge to this task in Hawaii in 1852.

Etymology

The English word "sugar" originates from the Arabic and Persian word shakar, itself derived from Sanskrit Sharkara . It came to English by way of French, Spanish and/or Italian, which derived their word for sugar from the Arabic and Persian shakar (whence the Portuguese word açúcar, the Spanish word azúcar, the Italian word zucchero, the Old French word zuchre and the contemporary French word sucre). (Compare the OED.) The Greek word for "sugar", zahari, means "sugar" or "pebble". Note that the English word jaggery (meaning "coarse brown Indian sugar") has similar ultimate etymological origins (presumably in Sanskrit).

As a food

Originally a luxury, sugar eventually became sufficiently cheap and common to influence standard cuisine. Britain and the Caribbean islands have cuisines where the use of sugar became particularly prominent.

Sugar forms a major element in confectionery and in desserts. Cooks use it as a food preservative as well as for sweetening.

Production

Harvested sugarcane from India ready for processing.

Table sugar (sucrose) comes from plant sources. Two important sugar crops predominate: sugarcane (Saccharum spp.) and sugar beets (Beta vulgaris), in which sugar can account for 12% to 20% of the plant's dry weight. Some minor commercial sugar crops include the date palm (Phoenix dactylifera), sorghum (Sorghum vulgare), and the sugar maple (Acer saccharum). In the financial year 2001/2002, worldwide production of sugar amounted to 134.1 million tonnes.

The first production of sugar from sugar-cane took place in India. Alexander the Great's companions reported seeing "honey produced without the intervention of bees" and it remained exotic in Europe until the Arabs started cultivating it in Sicily and Spain. Only after the Crusades did it begin to rival honey as a sweetener in Europe. The Spanish began cultivating sugar-cane in the West Indies in 1506 (and in Cuba in 1523). The Portuguese first cultivated sugar-cane in Brazil in 1532.

Most cane-sugar comes from countries with warm climates, such as Brazil, India, China, Thailand, Mexico and Australia, the top sugar-producing countries in the world. Brazil overshadows most countries, with roughly 30 million tonnes of cane-sugar produced in 2006, while India produced 21 million, China 11 million, and Thailand and Mexico roughly 5 million each. Viewed by region, Asia predominates in cane-sugar production, with large contributions from China, India and Thailand and other countries combining to account for 40% of global production in 2006. South America comes in second place with 32% of global production; Africa and Central America each produce 8% and Australia 5%. The United States, the Caribbean and Europe make up the remainder, with roughly 3% each.

Beet-sugar comes from regions with cooler climates: northwest and eastern Europe, northern Japan, plus some areas in the United States (including California). In the northern hemisphere, the beet-growing season ends with the start of harvesting around September. Harvesting and processing continues until March in some cases. The availability of processing-plant capacity, and the weather both influence the duration of harvesting and processing - the industry can lay up harvested beet until processed, but frost-damaged beet becomes effectively unprocessable.

The European Union (EU) has become the world's second-largest sugar exporter. The Common Agricultural Policy of the EU sets maximum quotas for members' production to match supply and demand, and a price. Europe exports excess production quota (approximately 5 million tonnes in 2003). Part of this, "quota" sugar, gets subsidised from industry levies, the remainder (approximately half) sells as "C quota" sugar at market prices without subsidy. These subsidies and a high import tariff make it difficult for other countries to export to the EU states, or to compete with the Europeans on world markets.

The United States sets high sugar prices to support its producers, with the effect that many former consumers of sugar have switched to corn syrup (beverage-manufacturers) or moved out of the country (candy-makers).

The cheap prices of glucose syrups produced from wheat and corn (maize) threaten the traditional sugar market. Used in combination with artificial sweeteners, they can allow drink-manufacturers to produce very low-cost goods.

Cane

Main article: Sugarcane

Since the 6th century BC cane-sugar producers have crushed the harvested vegetable material from sugar-cane in order to collect and filter the juice. They then treat the liquid (often with lime (calcium oxide)) to remove impurities and then neutralize it. Boiling the juice then allows the sediment to settle to the bottom for dredging out, while the scum rises to the surface for skimming off. In cooling, the liquid crystallizes, usually in the process of stirring, to produce sugar crystals. Centrifuges usually remove the uncrystallized syrup. The producers can then either sell the resultant sugar, as is, for use; or process it further to produce lighter grades. This processing may take place in another factory in another country.

Beet

Sugar beets

Main article: Sugar beet

Beet-sugar producers slice the washed beets, then extract the sugar with hot water in a "diffuser". An alkaline solution ("milk of lime" and carbon dioxide from the lime kiln) then serves to precipitate impurities (see carbonatation). After filtration, evaporation concentrates the juice to a content of about 70% solids, and controlled crystallisation extracts the sugar. A centrifuge removes the sugar crystals from the liquid, which gets recycled in the crystalliser stages. When economic constraints prevent the removal of more sugar, the manufacturer discards the remaining liquid, now known as molasses.

Sieving the resultant white sugar produces different grades for selling.

Cane versus beet

Little perceptible difference exists between sugar produced from beet and that from cane. Chemical tests can distinguish the two, and some tests aim to detect fraudulent abuse of European Union subsidies or to aid in the detection of adulterated fruit-juice.

The production of sugar-cane needs approximately four times as much water as the production of sugar-beet, therefore some countries that traditionally produced cane-sugar (such as Egypt) have seen the building of new beet-sugar factories recently. On the other hand, sugar cane tolerates hot climates better. Some sugar-factories process both sugar cane and sugar beets and extend their processing period in that way.

The production of sugar results in residues which differ substantially depending on the raw materials used and on the place of production. While cooks often use cane molasses in food-preparation, humans find molasses from sugar-beet unpalatable, and it therefore ends up mostly as industrial fermentation feedstock (for example in alcohol distilleries), or as animal-feed. Once dried, either type of molasses can serve as fuel for burning.

Culinary sugars

Grainier, raw sugar.

So-called raw sugars comprise yellow to brown sugars made by clarifying the source syrup by boiling and drying with heat, until it becomes a crystalline solid, with minimal chemical processing. Raw beet sugars result from the processing of sugar-beet juice, but only as intermediates en route to white sugar. Types of raw sugar include demerara, muscovado, and turbinado. Mauritius and Malawi export significant quantities of such specialty sugars. Manufacturers sometimes prepare raw sugar as loaves rather than as a crystalline powder, by pouring sugar and molasses together into molds and allowing the mixture to dry. This results in sugar-cakes or loaves, called jaggery or gur in India, pingbian tang in China, and panela, panocha, pile, piloncillo and pão-de-açúcar in various parts of Latin America. In South America, truly raw sugar, unheated and made from sugar-cane grown on farms, does not have a large market-share.

Mill white sugar, also called plantation white, crystal sugar, or superior sugar, consists of raw sugar where the production process does not remove colored impurities, but rather bleaches them white by exposure to sulfur dioxide. Though the most common form of sugar in sugarcane-growing areas, this product does not store or ship well; after a few weeks, its impurities tend to promote discoloration and clumping.

Blanco directo, a white sugar common in India and other south Asian countries, comes from precipitating many impurities out of the cane juice by using phosphatation — a treatment with phosphoric acid and calcium hydroxide similar to the carbonatation technique used in beet-sugar refining. In terms of sucrose purity, blanco directo is more pure than mill white, but less pure than white refined sugar.

White refined sugar has become the most common form of sugar in North America as well as in Europe. Refined sugar can be made by dissolving raw sugar and purifying it with a phosphoric acid method similar to that used for blanco directo, a carbonatation process involving calcium hydroxide and carbon dioxide, or by various filtration strategies. It is then further purified by filtration through a bed of activated carbon or bone char depending on where the processing takes place. Beet sugar refineries produce refined white sugar directly without an intermediate raw stage. White refined sugar is typically sold as granulated sugar, which has been dried to prevent clumping.

Granulated sugar comes in various crystal sizes — for home and industrial use — depending on the application:

• Coarse-grained sugars, such as sanding sugar (also called "pearl sugar", "decorating sugar", nibbed sugar or sugar nibs) adds "sparkle" and flavor for decorating to baked goods, candies, cookies/biscuits and other desserts. The sparkling effect occurs because the sugar forms large crystals which reflect light. Sanding sugar, a large-crystal sugar, serves for making edible decorations. It has larger granules that sparkle when sprinkled on baked goods and candies and will not dissolve when subjected to heat.
• Normal granulated sugars for table use: typically they have a grain size about 0.5 mm across
• Finer grades result from selectively sieving the granulated sugar
  • caster (or castor) (0.35 mm), commonly used in baking
  • superfine sugar, also called baker's sugar, berry sugar, or bar sugar — favored for sweetening drinks or for preparing meringue

• Finest grades
  • Powdered sugar, 10X sugar, confectioner's sugar (0.060 mm), or icing sugar (0.024 mm), produced by grinding sugar to a fine powder. The manufacturer may add a small amount of anti-caking agent to prevent clumping — either cornstarch (1% to 3%) or tri-calcium phosphate.

    

    Sugar-cubes close-up.

Retailers also sell sugar cubes or lumps for convenient consumption of a standardised amount. Suppliers of sugar-cubes make them by mixing sugar crystals with sugar syrup. Jakub Kryštof Rad invented sugar-cubes in 1841.

Brown sugar crystals.

Brown sugars come from the late stages of sugar refining, when sugar forms fine crystals with significant molasses-content, or from coating white refined sugar with a cane molasses syrup. Their color and taste become stronger with increasing molasses-content, as do their moisture-retaining properties. Brown sugars also tend to harden if exposed to the atmosphere, although proper handling can reverse this.

The World Health Organisation and the Food and Agriculture Organization of the United Nations expert report (WHO Technical Report Series 916 Diet, Nutrition and the Prevention of Chronic Diseases) defines free sugars as all monosaccharides and disaccharides added to foods by the manufacturer, cook or consumer, plus sugars naturally present in honey, syrups and fruit-juices. This includes all the sugars referred to above. The term distinguishes these forms from all other culinary sugars added in their natural form with no refining at all.

Natural sugars comprise all completely unrefined sugars: effectively all sugars not defined as free sugars. The WHO Technical Report Series 916 Diet, Nutrition and the Prevention of Chronic Diseases approves only natural sugars as carbohydrates for unrestricted consumption. Natural sugars come in fruit, grains and vegetables in their natural or cooked form.

Chemistry

Sucrose: a disaccharide of glucose (left) and fructose (right), important molecules in the body.

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 simple sugars (monosaccharides) conform to (CH₂O)_n where n is between 3 and 7. A notable exception, deoxyribose, as its name suggests, has a "missing" oxygen atom. All saccharides with more than one ring in their structure result from two or more monosaccharides joined by glycosidic bonds with the resultant loss of a molecule of water (H₂O) per bond.

As well as using classifications based on their reactive group, chemists may also subdivide sugars according to the number of carbons they contain. Derivatives of trioses (C₃H₆O₃) are intermediates in glycolysis. Pentoses (5-carbon sugars) include ribose and deoxyribose, which form part of nucleic acids. Ribose also forms a component of several chemicals that have importance in the metabolic process, including NADH and ATP. Hexoses (6-carbon sugars) include glucose, 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 (table sugar). Sucrose has the chemical formula C₁₂H₂₂O₁₁.

Many pentoses and hexoses can form ring structures. In these closed-chain forms, the aldehyde or ketone group remains unfree, 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 become metabolised. After digestion and absorption. the principal monosaccharides present in the blood and internal tissues include glucose, fructose, and galactose.

The prefix "glyco-" indicates the presence of a sugar in an otherwise non-carbohydrate substance. Note for example glycoproteins, proteins connected to one or more sugars.

Monosaccharides include fructose, glucose, galactose 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 C₁₂H₂₂O₁₁.

Hydrolysis can convert sucrose into a syrup of fructose and glucose, producing invert sugar. This resulting syrup, sweeter than the original sucrose, has uses in making confections because it does not crystallize as easily and thus produces a smoother finished product.

If combined with fine ash, sugar will burn with a blue flame.

Measuring sugar

See also International Commission for Uniform Methods of Sugar Analysis

Dissolved sugar content

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 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.

Purity

Technicians usually measure the purity (sucrose content) of sugar by polarimetry — the measurement of the rotation of plane-polarized light by a solution of sugar.

Baking weight/mass volume relationship

Sugar has a mass-to-volume relationship as follows:

Granular sugar 1 cup = 200g = 7 oz
Powdered sugar 1 cup = 100g = 3.5 oz
Brown sugar    1 cup = 220g = 7.8 oz

Trade and economics

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 kilograms 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.

World raw-sugar price for the calendar years 1960 to 2006.

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. This has led to numerous tariffs and levies in the past.

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-régime, 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,. On 25 November 2005 the Council of the EU agreed to cut EU sugar-prices by 36% as from 2009. It now seems that the U.S. Sugar Program could become the next target for reform. However, some commentators expect heavy lobbying from the U.S. sugar-industry, which donated $2.7 million to US House and US Senate incumbents in the 2006 US election, more than any other group of US food-growers. Especially prominent lobbyists include The Fanjul Brothers, so-called "sugar barons" who made the single largest individual contributions of soft money to both the Democratic and Republican parties in the political system of the United States of America.

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. However, the EU announced on 14 September 2007 that it would denounce the ACP Sugar Protocol with effect from 1 October 2009.

The Sugar Association has launched a campaign to promote sugar over artificial substitutes. The Association now aggressively challenges many common beliefs regarding negative side effects of sugar consumption. The campaign aired a high-profile television-commercial during the 2007 Prime Time Emmy Awards on FOX Television. The Sugar Association uses the trademark tagline "Sugar: sweet by nature."

See also

• Barley sugar
• Biobutanol
• Brown sugar
• Brix
• Caramel
• Corn syrup
• Fermentation
• Glycomics
• Golden syrup
• Holing cane
• List of unrefined sweeteners
• Natural brown sugar
• Palm sugar
• Rock candy
• Stevia
• Sugar plantations in the Caribbean
• Sugar loaf
• Sugar packet
• Sugar substitute

References

• Adas, Michael (January 2001). Agricultural and Pastoral Societies in Ancient and Classical History. Temple University Press. ISBN 1566398320.

• Robyt, John (January 1998). Essentials of Carbohydrate Chemistry. Springer-Verlag New York, LLC. ISBN 0387949518.

• James, Glyn (2004). Sugarcane. Blackwell Publishing. ISBN 063205476X.

• A C Hannah, The International Sugar Trade, Cambridge: Woodhead, 1996. ISBN 1-85573-069-3

• William Dufty, Sugar Blues, ISBN 0-446-34312-9

External links

History and culture

• Plant Cultures: botany, history and uses of sugar cane
• Big Sugar: documentary
• "From sweet on the table to fuel in the tank: the millenary history of Sugar Cane" Retrieved 2007-10-04

Food

• Cook's Thesaurus: Sugar (www.foodsubs.com)
• The Hidden Story of Big Sugar (www.macrobiotics.co.uk)

Health

• Expert Report on diet and chronic disease (WHO/FAO)
• Stop Being Sweet [1]
• Center for Science in the Public Interest sugar-labeling campaign

Social and environmental

• Ethical Sugar NGO
• The politics of sugar
• Harvesting Poverty: America's Sugar Daddies

Trade

• 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 and hyperactivity

• "The Myth of the Sugar Buzz" article from Skepticism.Net

Rare Sugar Research

• Rare Sugar Research Center