- This article deals with sugar as food and as an important, widely traded commodity; the word also has other uses; see Sugar (disambiguation)
A sugar is a form of carbohydrate; the most commonly used sugar is a white crystalline solid, sucrose; used to alter the flavor and properties ('mouthfeel', perservation, texture) of beverages and food. The "simple" sugars, such as glucose (which is produced from sucrose by enzymes or acid hydrolysis), are a store of energy which is used by biological cells.
For information on the other sugars see monosaccharide, disaccharide
Magnified view of refined sugar crystals.
In culinary terms, sugar is a type of food associated with one of the primary taste sensations, that of sweetness.
In the Southern United States, and in some regions of Europe, sugar or to have the sugar is slang for diabetes mellitus the medical condition in which sugar metabolism is disrupted.
Sugar (Azucar) or sucrose is extracted from sugar cane, sugar beets, or sugar palm by a refining process. In the financial year 2001/2002, 134.1 million tonnes of sugar were produced worldwide.
The major cane sugar producing countries are countries with warm climates, such as Australia, Brazil, and Thailand. In 2001/2002 there was over twice as much sugar produced in developing countries as in developed countries. The greatest quantity of sugar is produced in Latin America and the Caribbean nations, and in the Far East.
The sugar beet regions are in cooler climates; North West and Eastern Europe, Northern Japan, plus some areas in the United States including California. The beet growing season ends with the start of harvesting around September. Harvesting and processing continues until March in some cases. The duration of harvesting and processing is influenced by the availability of processing plant capacity, and weather - harvested beet can be laid up until processed but frost damaged beet becomes effectively unprocessable.
The world's second largest sugar exporter is the EU. The Common Agricultural Policy of the EU sets maximum quotas for members production to match supply and demand, and a price. Excess production quota is exported (approx 5 million tons 2003). Part of this is "quota" sugar which is subsidised from industry levies, the remainder (approx half) is "C quota" sugar which is sold at market price without subsidy. These subsidies and a high import tariff make it difficult for other countries to export to the EU states, or compete with it on world markets. The U.S. sets high sugar prices to support its producers with the effect that many sugar consumers have switched to corn syrup (beverage manufacturers) or moved out of the country (candy makers).
The sugar market is also under attack from the cheap prices of glucose syrups produced from wheat and corn (maize). In combination with artificial sweeteners drinks manufacturers can produce very low cost products.
The raw vegetable material is crushed, and the juice is collected and filtered. The liquid is then treated (often with lime) to remove impurities, this is then neutralised with sulfur dioxide. The juice is then boiled, sediment settles to the bottom and can be dredged out, scum rises to the surface and this is skimmed off. The heat is removed and the liquid crystallises, usually while being stirred, to produce sugar which can be poured into moulds. A centrifuge can also be used during crystallisation.
The washed beet is sliced, and the sugar extracted with hot water in a 'diffuser'. Impurities are precipitated with an alkaline solution "milk of lime" and carbon dioxide gas from the lime kiln. After filtration the juice is concentrated by evaporation to a content of about 70% solids. The sugar is extracted by controlled crystallisation. The sugar crystals are removed by a centrifuge and the liquid recycled in the crystalliser stages. Liquid from which no more sugar can be economically removed is lost from the process as molasses.
The white sugar produced is sieved into different grades for selling.
Cane vs Beet
There is little perceptible difference between sugar produced from beet and that from cane. Testing for impurities can distinguish the two, and these have been developed to reduce fraudulent abuse of EU subsidies, and also aid detection of adulteration of fruit juice.
The residues of sugar production differ substantially. While Cane molasses can be used as an ingredient, beet molasses is unpalatable and generally used for industrial fermentation or as animal feedstuff. Cane pulp can be burnt, beet pulp is dried, pelleted and used as an animal feedstuff.
Types of culinary sugar
Culinary sugar is available in many forms, from "brown" or "raw" (which is not truly raw, but refined from sugar cane or beets) to highly refined "white" sugar. Turbinado sugar is raw sugar that has been steam-cleaned. Muscovado sugar (UK) is dark brown with about 13% molasses content, or light brown with about 6% molasses. Demarara sugar has about 2% molasses. Other types of speciality sugar include Golden Granulated sugar, Golden Caster, Molasses sugar, Dark brown, Light brown, Coffee crystals and Organic sugar. Mauritius and Malawi are significant producers of speciality sugars.
While some of these forms may appear to be less processed than white sugar, some of them are made by adding back cane molasses to white sugar (both cane and beet).
Sugar comes in lumps, grains ('granulated sugar') and powder. Caster sugar (British English) or superfine sugar (USA) is finely granulated white sugar for use in a sprinkler or 'caster', and is generally used for baking eg cakes, meringues where its smaller size aids dissolution and for sweetening drinks. Icing sugar (British English) or confectioner's sugar (USA name) is finer than caster sugar, and is used for sugar icing, and dusting.
Sugar cubes, made of compacted sugar granules, are used to sweeten drinks.
Palm sugar, or jaggery, is obtained from the sap of the palm tree and is used in southeast Asia.
In biochemistry, a sugar is the simplest molecule that can be identified as a carbohydrate. These are monosaccharides and disaccharides. 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 (CH2O)n where n is between 3 and 7. A notable exception is deoxyribose, which as the name suggests is "missing" an oxygen. As well as being clasified by their reactive group, sugars are also classified by the number of carbons they contain. Derivatives of trioses (C3H6O3) are intermediates in glycolysis. Pentoses 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 include glucose which is a universal substrate for the production of energy in the form of ATP. During photosynthesis plants produce glucose which is then stored as starch.
Many pentoses and hexoses are capable of forming 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 as a ring 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. Glycosidic bonds must be hydrolysed or otherwise broken by enzymes before such compounds can be used in metabolism. After digestion and absorption the pricipal monosaccharieds present in the blood and internal tissues are: glucose, fructose, and galactose.
The term "glyco-" indicates the presence of a sugar in an otherwise non-carbohydrate substance: for example, a glycoprotein is a protein to which one or more sugars are connected.
Simple sugars include sucrose, fructose, glucose, galactose, maltose and mannose.
Sucrose can be converted by hydrolysis into a syrup of fructose and glucose, producing what is called invert sugar. This resulting syrup is sweeter than the original sucrose, and is useful for making confections sweeter and softer in texture.
Sugar cane has long been known in tropical areas of the world, and was chewed raw to extract its sweetness (sukha in Sanskrit). Later sugar refining was developed in the Middle East, India and China, where it became a staple of cooking and desserts. Later sugar spread to other areas of the world through trade. It arrived in Europe with the arrival of the Moors. Crusaders also brought sugar home with them after their campaigns in the Holy Land. While sugar cane could not be grown in northern Europe, sugar could be extracted from certain beets and these began to be widely cultivated around 1801, after the British control of the seas during the Napoleonic wars isolated mainland Europe from the Caribbean.
The History of Sugar in the West
In the 1390s, a better press, which doubled the juice obtained from the cane, was developed. This permitted economic expansion of sugar plantations to Andalusia and the Algarve. In the 1420s, sugar was carried to the Canary Islands and Madeira and Porto Santa Maria.
In 1493, Christopher Columbus stopped, intending to stay only four days, at Gomera in the Canary Islands, for wine and water. Columbus became romantically involved with the Governor of the Island, Beatrice. He stayed a month. When he finally sailed she gave him cuttings of sugarcane, the first to reach the New World.
The Portuguese took sugar to Brazil. Hans Staden, published in 1555, writes that by 1540 there were 800 sugar mills on Santa Catalina Island and another 2000 up the north coast of Brazil, Demarara and Surinam. Approximately 3000 small mills built before 1550 in the New World created an unprecedented demand for cast iron gears, levers, axes and other implements. Specialist 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. In the years 1625 to 1750, sugar was worth its weight in gold. Price declined slowly as production became multi-sourced especially through British colonial policy. Sugar production also increased in the American Colonies, Cuba, and Brazil. African slaves became the dominant plantation worker as they were resistant to the diseases of malaria and yellow fever. European indentured servants were in shorter supply, succeptible to disease and a less economic investment. Local Native Americans had been reduced by European diseases like smallpox.
With the European colonization of the Americas, the Caribbean became the world's largest source of sugar. Sugar cane could be grown on these islands using slave labour at vastly lower prices than sugar beets could be grown in Europe, or cane sugar imported from the East. Thus the economies of entire islands such as Guadaloupe and Barbados were based on sugar production. The largest sugar producer in the world, by 1750, was the French colony known as Saint-Domingue, which is today the independent country of Haiti. Jamaica was another major producer in the 1700s.
During the eighteenth century, sugar became enormously popular and went through a series of booms. The main reason for the heightened demand and production of sugar was 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 ninety-three and ninety-seven percent of the island’s exports, respectively.
Planters later began developing ways to boost production even more. For example, they began using more animal 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 prices of sugar reached soaring heights, especially during events such as the revolt against the Dutch and the Napoleonic wars. Sugar was a highly desired product, and the islands knew exactly how to take advantage of the situation.
As Europeans established sugar plantations on these larger Caribbean islands, prices fell, especially in Britain. What had previously been a luxury good began, by the eighteenth century, to be commonly consumed by all levels of society. At first most sugar in Britain was used in tea, but later candies and chocolates became extremely popular. Sugar was commonly sold in solid cones and required a sugar nip, a pliers-like tool, to break off pieces.
Sugar cane quickly exhausts the soil and larger islands with fresher soil were pressed into production in the nineteenth century. For example, it was in this century that Cuba rose as the richest land in the Caribbean (with sugar being its dominant crop) because it was the only major island that was free of mountainous terrain. Instead, nearly three-quarters of its land formed a rolling plain which was ideal for planting crops. Cuba also prospered above other islands because they used better methods when harvesting the sugar crops. They had been introduced to modern milling methods such as water mills, enclosed furnaces, steam engines, and vacuum pans. All these things increased their production and production rate.
After the world's only successful slave revolution established the independent nation of Haiti, sugar production in that country declined and Cuba replaced Saint-Domingue as the world's largest producer. Production spread to South America as well as to new European colonies in Africa and the Pacific.
The rise of Beet
The German scientist Margraaf had identified sugar in beet (the ancestor of sugar beet, beetroot and fodder beet. His student Achard improved the quality of the beet grown, and developed a factory process. This was largely ignored because of the availability of cane. During the Napoleonic Wars, Napoleon, fearful of the loss of sugar for the masses because of the British blockade against France, used Achard's work to develop the European production of sugar. Sugar production from beet came to the UK in the early 20th century.
While it is no longer grown by slaves, sugar growing in developing countries continues to this day to be associated with workers earning minimal wages and living in extreme poverty. Cuba was a large producer of sugar in the 20th century until the collapse of the Soviet Union took away their export market and the industry collapsed.
In the developed countries, the sugar industry is machine reliant, 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.
In 2003, a report was commissioned by two U.N. agencies, the World Health Organization and the Food and Agriculture Organization, compiled by a panel of 30 international experts. It stated that sugar should not account for more than 10% of a healthy diet. However, the Sugar Association (http://www.sugar.org/) of the US insists that other evidence indicates that a quarter of our food and drink intake can safely consist of sugar.
There is an on-going argument as to the value of extrinsic sugar (sugar added to food) compared to that of intrinsic (sugar, seldom sucrose, naturally present in food).
Sugar is an enormously important commodity throughout the world. However, many sugar farmers receive a low price for their produce. This has led to small quantities of sugar being available as a 'fair trade' item in some countries. More significantly in terms of quantity, the European Union and the USA provide preferential trade regimes to permit certain developing and least-developed countries to sell sugar at higher prices. The ACP-EU Sugar Protocol is an undertaking between the European Union and certain African, Caribbean and Pacific countries whereby the EU undertakes for an indefinite period to purchase and import, at guaranteed prices, specific quantities of cane sugar (in total 1.3 million tonnes), raw or white, which originate in the ACP states and which these States undertake to deliver to it. The agreement incorprates a prior agreement that the UK had to take raw sugar from the Caribbean (mostly Commonwealth states). The ACP-EU Sugar Protocol and the accompanying EU sugar regime is currently being challenged in a dispute in the WTO by Australia, Brazil and Thailand.
- Expert Report on diet and chronic disease (WHO/FAO) (http://www.who.int/mediacentre/releases/2003/pr20/en/)
- Sugar industry threatens to scupper WHO (Guardian) (http://www.guardian.co.uk/international/story/0,3604,940287,00.html)
- European Commission proposes to overhaul EU sugar regime (sugartraders.co.uk) (http://www.sugartraders.co.uk/)