Sucrose

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Sucrose
Identifiers
CAS number57-50-1 YesY
PubChem5988
ChemSpider5768 YesY
UNIIC151H8M554 YesY
EC-number200-334-9
DrugBankDB02772
ChEBICHEBI:17992 YesY
ChEMBLCHEMBL253582 YesY
RTECS numberWN6500000
Jmol-3D imagesImage 1
Properties[1]
Molecular formulaC12H22O11
Molar mass342.30 g/mol
Appearancewhite solid
Density1.587 g/cm3, solid
Melting point

186 °C decomp.

Solubility in water2000 g/L (25 °C)
log P−3.76
Structure
Crystal structureMonoclinic
Space groupP21
Hazards
MSDSICSC 1507
EU Indexnot listed
NFPA 704
NFPA 704.svg
1
1
0
Related compounds
Related compoundsLactose
Maltose
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references
 
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Sucrose
Identifiers
CAS number57-50-1 YesY
PubChem5988
ChemSpider5768 YesY
UNIIC151H8M554 YesY
EC-number200-334-9
DrugBankDB02772
ChEBICHEBI:17992 YesY
ChEMBLCHEMBL253582 YesY
RTECS numberWN6500000
Jmol-3D imagesImage 1
Properties[1]
Molecular formulaC12H22O11
Molar mass342.30 g/mol
Appearancewhite solid
Density1.587 g/cm3, solid
Melting point

186 °C decomp.

Solubility in water2000 g/L (25 °C)
log P−3.76
Structure
Crystal structureMonoclinic
Space groupP21
Hazards
MSDSICSC 1507
EU Indexnot listed
NFPA 704
NFPA 704.svg
1
1
0
Related compounds
Related compoundsLactose
Maltose
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Sucrose is the organic compound commonly known as table sugar and sometimes called saccharose. A white, odorless, crystalline powder with a sweet taste, it is best known for its nutritional role. The molecule is a disaccharide composed of the monosaccharides glucose and fructose with the molecular formula C12H22O11. The word was formed in mid-19th century from Latin sucrum = "sugar" and the chemical suffix -ose.

The world produced about 168 million tonnes of table sugar in 2011.[2]

Contents

Physical and chemical properties

Sucrose is a molecule with five stereocenters and many sites that are reactive or can be reactive. The molecule exists as a single isomer.

Structural α-D-glucopyranosyl-(1→2)-β-D-fructofuranoside

In sucrose, the components glucose and fructose are linked via an ether bond between C1 on the glucosyl subunit and C2 on the fructosyl unit. The bond is called a glycosidic linkage. Glucose exists predominantly as two isomeric "pyranoses" (α and β), but only one of these forms the links to the fructose. Fructose itself exists as a mixture of "furanoses", each of which having α and β isomers, but only one particular isomer links to the glucosyl unit. What is notable about sucrose is that, unlike most disaccharides, the glycosidic bond is formed between the reducing ends of both glucose and fructose, and not between the reducing end of one and the nonreducing end of the other. This linkage inhibits further bonding to other saccharide units. Since it contains no anomeric hydroxyl groups, it is classified as a nonreducing sugar.

Sucrose crystallizes in the monoclinic space group P21, with values at 300 K being a = 1.08631 nm, b = 0.87044 nm, c = 0.77624 nm, β = 102.938°.[3][4]

The usual measure of purity of sucrose is by polarimetry — the measurement of the rotation of plane-polarized light by a solution of sugar. The specific rotation at 20 °C using yellow "sodium-D" light (589 nm) is +66.47°. Commercial samples of sugar are assayed using this parameter. Sucrose is not damaged by air.

Thermal and oxidative degradation

Solubility of sucrose in water vs. temperature
T (°C)S (g/ml)
502.59
552.73
602.89
653.06
703.25
753.46
803.69
853.94
904.20

Sucrose decomposes as it melts at 186 °C (367 °F) to form caramel. Like other carbohydrates, it combusts to carbon dioxide and water. For example, in the amateur rocket motor propellant called rocket candy it is the fuel together with the oxidizer potassium nitrate.[citation needed]

48 KNO3 + 5 C12H22O11 → 24 K2CO3 + 24 N2 + 55 H2O + 36 CO2

Sucrose burns with chloric acid, formed by the reaction of hydrochloric acid and potassium chlorate:

8 HClO3 + C12H22O11 → 11 H2O + 12 CO2 + 8 HCl

Sucrose can be dehydrated with sulfuric acid to form a black, carbon-rich solid, as indicated in the following idealized equation:

H2SO4(catalyst) + C12H22O11 → 12 C + 11 H2O + heat and H2O + SO3 as a result of heat

Hydrolysis

Hydrolysis breaks the glycosidic bond converting sucrose into glucose and fructose. Hydrolysis is, however, so slow that solutions of sucrose can sit for years with negligible change. If the enzyme sucrase is added, however, the reaction will proceed rapidly.[5] Hydrolysis can also be accelerated with acids, such as cream of tartar or lemon juice, both weak acids. Likewise, gastric acidity converts sucrose to glucose and fructose during digestion.

Synthesis and biosynthesis of sucrose

The biosynthesis of sucrose proceeds via the precursors UDP-glucose and fructose 6-phosphate, catalyzed by the enzyme sucrose-6-phosphate synthase. The energy for the reaction is gained by the cleavage of Uridine diphosphate (UDP). Sucrose is formed by plants and cyanobacteria but not by other organisms. Sucrose is found naturally in many food plants along with the monosaccharide fructose. In many fruits, such as pineapple and apricot, sucrose is the main sugar. In others, such as grapes and pears, fructose is the main sugar.

Chemical synthesis

Model of sucrose molecule.

Although sucrose is invariably isolated from natural sources, its chemical synthesis was first achieved in 1953 by Raymond Lemieux.[6]

As a food

Refined sugar was a luxury before the 18th century. It became widely popular in 18th century, then graduated to becoming a necessary food in the 19th century. This evolution of taste and demand for sugar as an essential food ingredient unleashed major economic and social changes.[7] Eventually, table sugar became sufficiently cheap and common enough to influence standard cuisine and flavored drinks.

Sucrose forms a major element in confectionery and desserts. Cooks use it for sweetening — its fructose component, which has almost double the sweetness of glucose, makes sucrose distinctively sweet in comparison to other carbohydrate foods.[8] It can also act as a food preservative when used in sufficient concentrations. Sucrose is important to the structure of many foods, including biscuits and cookies, cakes and pies, candy, and ice cream and sorbets. It is a common ingredient in many processed and so-called "junk foods."

Metabolism of sucrose

Granulated sucrose

In humans and other mammals, sucrose is broken down into its constituent monosaccharides, glucose and fructose, by sucrase or isomaltase glycoside hydrolases, which are located in the membrane of the microvilli lining the duodenum.[9][10] The resulting glucose and fructose molecules are then rapidly absorbed into the bloodstream. In bacteria and some animals, sucrose is digested by the enzyme invertase.

Sucrose is an easily assimilated macronutrient that provides a quick source of energy, provoking a rapid rise in blood glucose upon ingestion. Overconsumption of sucrose has been linked with adverse health effects. The most common is dental caries or tooth decay, in which oral bacteria convert sugars (including sucrose) from food into acids that attack tooth enamel.

Sucrose, as a pure carbohydrate, has an energy content of 3.94 kilocalories per gram (or 17 kilojoules per gram). When large amounts of refined food that contain high percentages of sucrose are consumed, beneficial nutrients can be displaced from the diet, which can contribute to an increased risk for chronic disease. It has been suggested that sucrose-containing drinks may be linked to the development of obesity and insulin resistance.[11]

The rapidity with which sucrose raises blood glucose can cause problems for people suffering from defective glucose metabolism, such as persons with hypoglycemia or diabetes mellitus. Sucrose can contribute to the development of metabolic syndrome.[12] In an experiment with rats that were fed a diet one-third of which was sucrose, the sucrose first elevated blood levels of triglycerides, which induced visceral fat and ultimately resulted in insulin resistance.[13] Another study found that rats fed sucrose-rich diets developed high triglycerides, hyperglycemia, and insulin resistance.[14]

Human health

Human beings have long sought sugars, but aside from wild honey, have not had access to the large quantities that characterize the modern diet. Studies have indicated potential links between processed sugar consumption (otherwise referred to as free sugars) and health hazards, including obesity and tooth decay[15][16] and is relevant to other chemical forms of sugar, not just sucrose. It is also considered as a source of endogenous glycation processes.[citation needed]

Tooth decay

Tooth decay has become a prominent health hazard associated with the consumption of sugar. Oral bacteria such as Streptococcus mutans live in dental plaque and metabolize any sugars (not just sucrose, but also glucose, lactose, fructose, and cooked starches[17]) into lactic acid. High concentrations of acid may result on the surface of a tooth, leading to tooth demineralization.[18][19]

All 6-carbon sugars and disaccharides based on 6-carbon sugars can be converted by dental plaque bacteria into acid that demineralizes teeth, but sucrose may be uniquely useful to Streptococcus mutans.[20] Sucrose may be the sugar most efficiently converted to dextran, with which the bacteria glues itself to the tooth surface. Thus, sucrose could enable Streptococcus mutans to adhere more strongly and resist attempts at removal. The dextran itself also acts as a reserve food supply for the bacteria. Such a special role of sucrose in the formation of tooth decay is much more significant in light of the almost universal use of sucrose as the most desirable sweetening agent.

Glycemic index and by-products of sucrose

Sucrose is a disaccharide made up of 50% glucose and 50% fructose and has a moderately high glycemic index of 80, about the same as pasteurized processed honey, 75, and more than raw honey, 35,[21] but not nearly that of maltose, which is a disaccharide made up of 100% glucose (i.e., 2 parts glucose), 105,[22] which, in turn, causes an immediate response within the body's digestive system. As with other sugars, sucrose is digested into its components via the enzyme sucrase; to glucose (blood sugar) and fructose. The glucose component is transported into the blood (90%) and excess glucose is converted to temporary storage in the liver – named glycogen. The fructose is either bonded to cellulose and transported out the GI tract or processed by the liver into citrates, aldehydes, and, for the most part, lipid droplets (fat).

As the glycemic index measures the speed at which glucose is released into the bloodstream a refined sugar containing glucose is considered high-glycemic. As with other sugars, over-consumption may cause an increase in blood sugar levels from a normal 90 mg/dL to up over 150 mg/dL.[23] (5 mmol/l to over 8.3 mmol/l).

Diabetes mellitus

Diabetes Mellitus, a disease that causes the body to metabolize sugar poorly, occurs when either:

  1. the body attacks the cells producing insulin, the hormone that allows the metabolizing of sugar (Type 1 diabetes)
  2. the body's cells exhibit impaired responses to insulin (Type 2 diabetes).

When glucose builds up in the bloodstream, it can cause two problems:

  1. in the short term, cells become starved for energy because they do not have access to the glucose
  2. in the long term, frequent glucose build-up increases the acidity of the blood, damaging many of the body's organs, including the eyes, kidneys, nerves, and/or heart.

Authorities advise diabetics to avoid sugar-rich foods to prevent adverse reactions.[24]

Obesity

The National Health and Nutrition Examination Survey I and their follow-on studies as part of a series indicate that the population in the United States has increased its proportion of energy consumption from carbohydrates and decreased its proportion from total fat while obesity has increased. This implies, along with the United Nations report cited below, that obesity may correlate better with sugar consumption than with fat consumption, and that reducing fat consumption while increasing sugar consumption actually increases the level of obesity. The following table summarizes this study (based on the proportion of energy intake from different food sources for US Adults 20–74 years old, as carried out by the U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Health Statistics, Hyattsville, MD[25]):

YearSexCarbohydrateFatProteinObesity
1971Male42.4%36.9%16.5%12.1%
1971Female45.4%36.1%16.9%16.6%
2000Male49.0%32.8%15.5%27.7%
2000Female51.6%32.8%15.1%34.0%

A 2002 study conducted by the U.S. National Academy of Sciences concluded that, due to discrepancies in data from different studies, it could not set a tolerable upper intake level, since "there is no clear and consistent association between increased intakes of added sugars and BMI." However, it explains that this may be due to the underreporting of the consumption of added sugars. (BMI, or "body mass index," is a measure of weight and height used to estimate body fat.)[26]

Gout

The occurrence of gout is connected with an excess production of uric acid. A diet rich in sucrose may lead to gout as it raises the level of insulin, which prevents excretion of uric acid from the body. As the concentration of uric acid in the body increases, so does the concentration of uric acid in the joint liquid and beyond a critical concentration, the uric acid begins to precipitate into crystals. Researchers have implicated sugary drinks high in fructose in a surge in cases of gout.[27][28]

United Nations nutritional advice

In 2003, four United Nations agencies (including the World Health Organization and the Food and Agriculture Organization) commissioned a report compiled by a panel of 30 international experts. The panel stated that the total of free sugars (all monosaccharides and disaccharides added to foods by manufacturers, cooks or consumers, plus sugars naturally present in honey, syrups, and fruit juices) should not account for more than 10% of the energy intake of a healthy diet, while carbohydrates in total should represent between 55% and 75% of the energy intake.[29]

Debate on extrinsic sugar

Argument continues as to the value of extrinsic sugar (sugar added to food) compared to that of intrinsic sugar (naturally present in food). Adding sugar to food sweetens the taste, but increases the total number of calories, among other negative effects on health and physiology.

In the US, sugar has become increasingly evident in food products, as more food manufacturers add sugar or high-fructose corn syrup to a wide variety of consumables. Candy bars, soft drinks, potato chips, snacks, fruit juice, peanut butter, soups, ice cream, jams, jellies, yogurt, and many breads may have added sugars.

Religious, vegetarian and vegan concerns

The sugar refining industry often uses bone char (calcinated animal bones) for decolorizing.[30][31] About 25% of sugar produced in the U.S. is processed using bone char as a filter, the remainder being processed with activated carbon. As bone char does not seem to remain in finished sugar, Jewish religious leaders consider sugar filtered through it to be parve and therefore kosher. In contrast, Muslims consider filtered sugar to be haraam because the animals may have been improperly slaughtered or bone char may contain pork remains.[31]

Production

History of sucrose production

Table sugar production in the 19th century. Sugar cane plantations (upper image) employed slave or indentured laborers. The picture shows workers harvesting cane, loading it on a boat for transport to the plant, while a European overseer watches in the lower right. The lower image shows a sugar plant with two furnace chimneys. Sugar plants and plantations were harsh, inhumane work.[32]
A sugarloaf was a traditional form for sugar in the 17th to 19th centuries. Sugar nips were required to break off pieces.

The production of table sugar has a long history. The army of Alexander the Great was halted on the banks of river Indus by the refusal of his troops to go further east. They saw people in the Indian subcontinent growing sugarcane and making granulated, salt-like sweet powder, locally called साखर, pronounced as saccharum (ζάκχαρι). On their return journey, the Macedonian soldiers carried the "honey bearing reeds." Sugarcane remained a limited crop for over a millennium; sugar, a rare commodity; and traders of sugar, wealthy. Venice, at the height of its financial power, was the chief sugar-distributing center of Europe.[33] Arabs started producing it in Sicily and Spain. Only after the Crusades did it begin to rival honey as a sweetener in Europe. The Spanish began cultivating sugarcane in the West Indies in 1506 (and in Cuba in 1523). The Portuguese first cultivated sugarcane in Brazil in 1532.

Some scholars claim Indians discovered how to crystallize sugar during the Gupta dynasty, around AD 350.[34]

Other scholars point to the ancient manuscripts of China, dated to be from the eight century BC, where one of the earliest historical mention of sugar cane is included along with the fact that their knowledge of sugar cane was derived from India.[33] Further, it appears that by about 500 BC, residents of present-day India began making sugar syrup and cooling it in large flat bowls to make raw table sugar crystals that were easier to store and transport. In the local Indian language, these crystals were called khanda (खण्ड), which is the source of the word candy.[35]

Regardless of which century table sugar production was discovered, it was a luxury in much of the world until the 18th century. Only the royalty and very wealthy could afford sugar. In 18th century, the demand for table sugar boomed in Europe, and by 19th century it had become a human necessity.[7] The use of sugar grew from use in tea, to cakes, confectionery and chocolates. Suppliers marketed sugar in novel forms, such as solid cones which consumers required a sugar nip, a pliers-like tool, to break off pieces.

The demand for cheaper table sugar drove, in part, colonization of tropical islands and nations where labor-intensive sugarcane plantations and table sugar manufacturing could thrive. Growing sugar cane crop in hot humid climate, and producing table sugar in high temperature sugar mills was harsh, inhumane work. The demand for cheap and docile labor for this work, in part, first drove slave trade from Africa (in particular West Africa), followed by indentured labor trade from South Asia (in particular India).[32][36][37] Millions of slaves, followed by millions of indentured laborers were brought into the Caribbean, Indian Ocean, Pacific Islands, East Africa, Natal, north and eastern parts of South America, and southeast Asia. The modern ethnic mix of many nations, settled in last two centuries, has been influenced by table sugar.[38][39][40]

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. During the same century, Europeans began experimenting with sugar production from other crops. Andreas Marggraf identified sucrose in beet root and his student Franz Achard built a sugar beet processing factory in Silesia (Poland). However, the beet-sugar industry really took off during the Napoleonic Wars, when France and the continent were cut off from Caribbean sugar. In 2010, about 20 percent of the world's sugar was produced from beets.[41]

Today, a large beet refinery producing around 1,500 tonnes of sugar a day needs a permanent workforce of about 150 for 24-hour production.

Current trends in sucrose production

Harvested sugarcane from Venezuela ready for processing.
A table sugar factory in England. The tall diffusers are visible to the middle left where the harvest transforms into a sugar syrup. The boiler and furnace are in the center, where table sugar crystals form. An expressway for transport is visible in the lower left.

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. Minor commercial sugar crops include the date palm (Phoenix dactylifera), sorghum (Sorghum vulgare), and the sugar maple (Acer saccharum). Sucrose is obtained by extraction of these crops with hot water, concentration of the extract gives syrups, from which solid sucrose can be crystallized. In 2011, worldwide production of table sugar amounted to 168 million tonnes.[2]

Most cane sugar comes from countries with warm climates, because sugar cane crop does not tolerate frost. Sugar beets, on the other hand, grow only in cooler temperate regions and do not tolerate extreme heat. About 80 percent of sucrose is derived from sugar cane, the rest almost all from sugar beet.

In 2010, Brazil, India, European Union, China, Thailand, and United States were the major sugar-producing countries in the world.[42] Brazil produced about 38 million tonnes of table sugar in 2010, while India produced 27 million, EU-27 countries 15 million, China 11 million, Thailand about 10 million, and United States over 7 million.[2] Sugar production is a growth industry. The country rankings for table sugar production change with each years sugar cane crop harvest and as new sugar production plants are commissioned worldwide.

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.[42]

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 a 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 purchasers of sugar have switched to corn syrup (beverage manufacturers) or moved out of the country (candymakers).

The low 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.

High-fructose corn syrup usage in USA

Sucrose has been partially replaced in American industrial food production by other sweeteners such as fructose syrups or combinations of functional ingredients and high-intensity sweeteners. This shift is attributable to governmental subsidies of U.S. corn and an import tariff on foreign sugar, raising the price of sucrose to levels above those of the rest of the world.[43] Because of the artificially elevated price of sucrose, HFCS is cost efficient for many sweetener applications.

Cane

Since the 6th century BC, cane sugar producers have crushed the harvested vegetable material from sugarcane 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 sugar product for use as is, or process it further to produce lighter grades. The later processing may take place in another factory in another country.

Sugarcane is a major component of Brazilian agriculture; the country is a top producer of sugarcane products, such as crystallized sugar and ethanol (ethanol fuel). The sucrose found in sugarcane produces ethanol when fermented and distilled. Brazil has implemented ethanol as an alternative fuel on a national scale.[44]

Beet

Sugar beets

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[clarification needed], 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, or sells it on to producers of animal feed.

Sieving the resultant white sugar produces different grades for selling.

Cane versus beet

It is difficult to tell the difference between fully refined sugar produced from beet and cane. One way is by isotope analysis of carbon. Cane uses C4 carbon fixation, and beet C3 carbon fixation, resulting in a different ratio of 13C and 12C isotopes in the sucrose. Tests are used to detect fraudulent abuse of European Union subsidies or to aid in the detection of adulterated fruit juice.

The production of sugarcane 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 that 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 beets 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.

Pure beet sugar is difficult to find in the marketplace. Although some brands label their product clearly as "pure cane sugar", beet sugar is almost always labeled simply as sugar or pure sugar. Interviews with the 5 major beet sugar-producing companies revealed that many store brands or "private label" sugar products are pure beet sugar. The lot code can be used to identify the company and the plant from which the sugar came, thus enabling the savvy shopper to identify beet sugar in the store.[45]

Culinary sugars

Grainy 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.[citation needed] 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 sugarcane grown on farms, does not have a large market-share.[clarification needed]

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[clarification needed] stage. White refined sugar is typically sold as granulated sugar, which has been dried to prevent clumping.

Granulated sugar for table use.

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

Sugar cubes close-up.

Retailers also sell sugar cubes or lumps for convenient consumption of a standardized amount. Suppliers of sugarcubes make them by mixing sugar crystals with sugar syrup. Jakub Kryštof Rad invented sugarcubes in 1841 in the Czech part of former Austrian Empire (what is now the Czech Republic).[47]

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.

Dissolved sugar content

Scientists and the sugar industry use degrees Brix (symbol °Bx), introduced by Adolf 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.

The Brix degrees are measured using an infrared sensor. This measurement 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.

Baking weight/mass volume relationship

Different culinary sugars have different densities due to variation in particle size and inclusion of moisture.

The Domino Sugar Company has established the following volume to weight conversions:

Trade and economics

One of the most widely-traded commodities in the world throughout history, sugar accounts for around 2% of the global dry cargo market.[citation needed] International sugar prices show great volatility, ranging from around 3 to over 60 cents per pound in the past 50 years. About 100 of the world's 180 countries 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.[citation needed] Consumption per capita rises with income per capita until it reaches a plateau of around 35 kg per person per year in middle income countries.

World raw sugar price from 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 in essence 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.[48] 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.[49] The African, Caribbean, Pacific and least developed country sugar exporters reacted with dismay to the EU sugar proposals.[50] On 25 November 2005, the Council of the EU agreed to cut EU sugar prices by 36% as from 2009. In 2007, it seemed[51] that the U.S. Sugar Program could become the next target for reform. However, some commentators expected 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.[52] 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.[53][54]

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 $60.00 per tonne to small farmers for sugar branded as "Fairtrade",[55] government schemes such the U.S. Sugar Program and the ACP Sugar Protocol offer premiums of around $400.00 per tonne above world market prices. However, the EU announced on 14 September 2007 that it had offered "to eliminate all duties and quotas on the import of sugar into the EU".[56]

The US 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 Primetime Emmy Awards on FOX Television. The Sugar Association uses the trademark tagline "Sugar: sweet by nature."[57]

References

  1. ^ Sucrose, International Chemical Safety Card 1507, Geneva: International Programme on Chemical Safety, November 2003, http://www.inchem.org/documents/icsc/icsc/eics1507.htm
  2. ^ a b c "Sugar: World Markets and Trade". United States Department of Agriculture. November 2011. http://www.fas.usda.gov/htp/sugar/2011/Nov2011sugar.pdf.
  3. ^ C. A. Beevers, T. R. R. McDonald, J. H. Robertson and F. Stern (1952). "The crystal structure of sucrose". Acta Cryst 5 (5): 689–690. doi:10.1107/S0365110X52001908.
  4. ^ Hynes, R. C.; Le Page, Y. (1991). "Sucrose, a convenient test crystal for absolute structures". Journal of Applied Crystallography 24 (4): 352. doi:10.1107/S0021889891002492.
  5. ^ "Sucrase", Encyclopædia Britannica Online
  6. ^ Lemieux, R. U.; Huber, G. (1953). "A chemical synthesis of sucrose". J. Am. Chem. Soc. 75 (16): 4118. doi:10.1021/ja01112a545.
  7. ^ a b Sidney Mintz (1986). Sweetness and Power: The Place of Sugar in Modern History. Penguin. ISBN 978-0-14-009233-2.
  8. ^ Taubes, Gary. (April 13, 2011). Is Sugar Toxic?. The New York Times.
  9. ^ Gray GM (1971). "Intestinal Digestion and Maldigestion of Dietary Carbohydrate". Annual Review of Medicine 22: 391–404. doi:10.1146/annurev.me.22.020171.002135. PMID 4944426.
  10. ^ Kaneko JJ. Carbohydrate metabolism and its diseases. In Kaneko JJ, Harvey JW, Bruss ML, eds. Clinical Biochemistry of Domestic Animals, San Diego, CA: Academic Press (2008) p. 46 ISBN 012370491.
  11. ^ Ten, Svetlana; Maclaren, Noel (2004). "Insulin resistance syndrome in children". J. Clin. Endocrinol. Metab. 89 (6): 2526–39. doi:10.1210/jc.2004-0276. PMID 15181020.
  12. ^ Alexander Aguilera, Alfonso; Hernández Díaz, Guillermo; Lara Barcelata, Martín; Angulo Guerrero, Ofelia; Oliart Ros, Rosa M. (2004). "Effects of fish oil on hypertension, plasma lipids, and tumor necrosis factor-alpha in rats with sucrose-induced metabolic syndrome". J. Nutr. Biochem. 15 (6): 350–57. doi:10.1016/j.jnutbio.2003.12.008. PMID 15157941.
  13. ^ Fukuchi, Satoshi; Hamaguchi, Kazuyuki; Seike, Masataka; Himeno, Katsuro; Sakata, Toshiie; Yoshimatsu, Hironobu (2004). "Role of Fatty Acid Composition in the Development of Metabolic Disorders in Sucrose-Induced Obese Rats". Exp. Biol. Med. 229 (6): 486–93. PMID 15169967.
  14. ^ Lombardo, Y. B.; Drago, S.; Chicco, A.; Fainstein-Day, P.; Gutman, R.; Gagliardino, J. J.; Gomez Dumm, C. L. (1996). "Long-term administration of a sucrose-rich diet to normal rats: relationship between metabolic and hormonal profiles and morphological changes in the endocrine pancreas". Metabolism 45 (12): 1527–32. doi:10.1016/S0026-0495(96)90183-3. PMID 8969287.
  15. ^ Joint WHO/FAO Expert Consultation, 2003, "WHO Technical Report Series 916 Diet, Nutrition and the Prevention of Chronic Diseases", Geneva
  16. ^ Diet, nutrition and the prevention of dental diseases, Paula Moynihan, WHO Collaborating Centre for Nutrition and Oral Health, School of Dental Sciences, University of Newcastle and Poul Erik Petersen, WHO Collaborating Centre for Community Oral Health Programmes and Research, University of Copenhagen, Public Health Nutrition: 7(1A), 201–226
  17. ^ "What causes tooth decay?". Animated-teeth.com. http://www.animated-teeth.com/tooth_decay/t2_tooth_decay_caries.htm. Retrieved 2010-05-05.
  18. ^ Tooth Decay. Elmhurst.edu. Retrieved on 2011-11-18.
  19. ^ What causes tooth decay?. Animated-teeth.com. Retrieved on 2011-11-18.
  20. ^ Tanzer, JM (1979 Aug). "Essential dependence of smooth surface caries on, and augmentation of fissure caries by, sucrose and Streptococcus mutans infection". Infection and immunity 25 (2): 526–31. PMC 443577. PMID 489122. //www.ncbi.nlm.nih.gov/pmc/articles/PMC443577/.
  21. ^ "Healthy Sugar Alternatives". Organic Lifestyle Magazine. http://www.organiclifestylemagazine.com/healthy-sugar-alternatives/. Retrieved 2012-07-20.
  22. ^ "Glycemic Index". Diabetesnet.com. http://www.diabetesnet.com/diabetes_food_diet/glycemic_index.php. Retrieved 2010-05-05.
  23. ^ Baschetti, R (2004). "Evolutionary legacy: form of ingestion, not quantity, is the key factor in producing the effects of sugar on human health". Medical hypotheses 63 (6): 933–8. doi:10.1016/j.mehy.2004.07.018. PMID 15504559.
  24. ^ What I need to know about Eating and Diabetes. Diabetes.niddk.nih.gov. Retrieved on 2011-11-18.
  25. ^ National Health and Nutrition Examination Survey. Cdc.gov. Retrieved on 2011-11-18.
  26. ^ Dietary reference intakes: guiding principles for nutrition labeling and fortification. National Academies Press. 2004. ISBN 0-309-09132-2. http://books.google.com/?id=XzjYhuCGrL0C&printsec=frontcover.
  27. ^ Gout surge blamed on sweet drinks, BBC News, 1 February 2008
  28. ^ "Nutrients for Gout – good and bad – Doctor's Corner Newsletter Archive". ABCVitaminsLife.com. 2007-07-30. http://www.abcvitaminslife.com/HealthFacts/Article429.aspx. Retrieved 2010-05-05.
  29. ^ See table 6, page 56 of the WHO Technical Report Series 916, Diet, Nutrition and the Prevention of Chronic Diseases
  30. ^ The Great Sugar Debate: Is it Vegan?. Vegfamily.com. Retrieved on 2011-11-18.
  31. ^ a b Yacoubou, MS, Jeanne (2007). "Is Your Sugar Vegan? An Update on Sugar Processing Practices" (PDF). Vegetarian Journal (Baltimore, MD: The Vegetarian Resource Group) 26 (4): 16–20. https://www.vrg.org/journal/vj2007issue4/vj2007issue4.pdf. Retrieved 2007-04-04.
  32. ^ a b "Forced Labour". The National Archives, Government of the United Kingdom. 2010. http://www.nationalarchives.gov.uk/pathways/blackhistory/india/forced.htm.
  33. ^ a b George Rolph (1873). Something about sugar: its history, growth, manufacture and distribution. http://www.archive.org/details/somethingaboutsu00rolprich.
  34. ^ Adas, Michael (January 2001). Agricultural and Pastoral Societies in Ancient and Classical History. Temple University Press. ISBN 1-56639-832-0. p. 311.
  35. ^ "Sugarcane: Saccharum Offcinarum". USAID, Govt of United States. 2006. p. 7.1. http://www.usaid.gov/locations/latin_america_caribbean/environment/docs/ag&environ/Sugarcane.pdf.
  36. ^ Walton Lai (1993). Indentured labor, Caribbean sugar: Chinese and Indian migrants to the British West Indies, 1838–1918. ISBN 978-0-8018-7746-9.
  37. ^ Steven Vertovik (Robin Cohen, ed.) (1995). The Cambridge survey of world migration. pp. 57–68. ISBN 978-0-521-44405-7.
  38. ^ K Laurence (1994). "A Question of Labour: Indentured Immigration Into Trinidad & British Guiana, 1875–1917". St Martin's Press. ISBN 978-0-312-12172-3.
  39. ^ "St. Lucia’s Indian Arrival Day". Caribbean Repeating Islands. 2009. http://repeatingislands.com/2009/05/07/st-lucia’s-indian-arrival-day/.
  40. ^ "Indian indentured labourers". The National Archives, Government of the United Kingdom. 2010. http://www.nationalarchives.gov.uk/records/research-guides/indian-indentured-labour.htm.
  41. ^ "Agribusiness Handbook: Sugar beet white sugar". Food and Agriculture Organization, United Nations. 2009. http://www.eastagri.org/publications/pub_docs/4_Sugar_web.pdf.
  42. ^ a b Food and Agriculture Organization of the United Nations. Faostat.fao.org (2011-05-17). Retrieved on 2011-11-18.
  43. ^ Miraski, Benjamin (June 5, 2008). "Sugar's money, influence continue to plague domestic candy companies". Medill Reports. http://news.medill.northwestern.edu/chicago/news.aspx?id=92869.
  44. ^ Bolling, Suarez, Christine, Nydia R.. "The Brazilian Sugar Industry: Recent Developments". Brazil, sugarcane, sugar, ethanol, production, exports, prices.. USDA. http://www.ers.usda.gov/briefing/brazil/braziliansugar.pdf. Retrieved 11/10/11.
  45. ^ January 2010 Newsletter, IBS Treatment Center
  46. ^ The Oxford English Dictionary classifies both spellings as correct, but "castor" used to prevail.
  47. ^ Dacice and the world’s first sugar cube. dacice.cz
  48. ^ EC – Export subsidies on sugar. (PDF). wto.org. Retrieved on 2011-11-18.
  49. ^ Agriculture – Sugar. Ec.europa.eu (2004-07-14). Retrieved on 2011-11-18.
  50. ^ ACP Group of States – The Fiji Communiqué on Sugar. Acpsec.org (2007-05-03). Retrieved on 2011-11-18.
  51. ^ International Sugar Trade Coalition. Sugarcoalition.org. Retrieved on 2011-11-18.
  52. ^ New York Times, October 18, 2007, Seeing Sugar’s Future in Fuel
  53. ^ New York Times, November 11, 2003, America’s Sugar Daddies
  54. ^ "Sugar Daddie$". Mother Jones. 1997-05-01. http://www.motherjones.com/news/special_reports/coinop_congress/97mojo_400/boller.html. Retrieved 2010-05-05.
  55. ^ Sugar. FLO (Fairtrade Labelling Organizations International)
  56. ^ European Commission – External Trade – Trade Issues. Ec.europa.eu (2010-05-06). Retrieved on 2011-11-18.
  57. ^ Sugar Association. Sugar.org. Retrieved on 2011-11-18.

Further reading

External links