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 the sweetener in Europe. The Spanish began cultivating sugar cane in the West Indies in 1506, and in Cuba in 1523. It was first cultivated in Brazil 1532 by the Portuguese.
Table sugar or sucrose comes from plant sources. The most important two sugar crops are sugarcane (Saccharum spp.) and sugar beets (Beta vulgaris), in which sugar can account for 12%–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, 134.1 million tonnes of sugar were produced worldwide.
Most cane sugar comes from countries with warm climates, such as Brazil, India, China and Australia (in descending order). 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, the United States and the Caribbean nations, and in the Far East.
Beet sugar comes from regions with cooler climates: northwest 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 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. Excess production quota is exported (approx 5 million tonnes in 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 cheap prices of glucose syrups produced from wheat and corn (maize) threaten the traditional sugar market. In combination with artificial sweeteners, drink manufacturers can produce very low-cost products.
Cane
Cane-sugar producers crush the harvested vegetable material, then collect and filter the juice. They then treat the liquid (often with lime (calcium oxide)) to remove impurities, this is then neutralized with sulfur dioxide. The juice is then boiled, the 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 crystals. It is usual to remove the uncrystallised syrup with a centrifuge. The resultant sugar is then either sold as is for use or processed further to produce lighter grades. This processing may take place in another factory in another country.
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 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. 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. Tests can distinguish the two, and some tests aim to detect fraudulent abuse of EU subsidies or to aid in the detection of adulterated fruit-juice.
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, humans find molasses from sugar beet unpalatable, and it therefore ends up mostly as industrial fermentation feedstock, or as animal-feed. Once dried, either type of molasses can serve as fuel for burning.
Culinary sugars
Raw sugars comprise yellow to brown sugars made from clarified cane-juice boiled down to a crystalline solid with minimal chemical processing. Raw sugars are produced in the processing of sugar beet juice but only as intermediates en route to white sugar. Types of raw sugar available as a specialty item outside the tropics include demerara, muscovado, and turbinado. Mauritius and Malawi export significant quantities of such specialty sugars. Raw sugar is sometimes prepared as loaves rather than as a crystalline powder: in this technique, sugar and molasses are poured together into molds and allowed to dry. The resulting sugar cakes or loaves are called jaggery or gur in India, pingbian tong in China, and panela, panocha, pile, and piloncillo in various parts of Latin America.
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. This is the most common form of sugar in sugarcane growing areas, but 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 decolorized 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 (nibbed sugar or sugar nibs) find favor for decorating cookies (biscuits) and other desserts.
* Normal granulated for table use typically has a grain size about 0.5 mm across
* Finer grades result from selectively sieving the granulated sugar
o caster sugar (0.35 mm), commonly used in baking
o superfine sugar, also called baker's sugar, berry sugar, or bar sugar — favored for sweetening drinks or for preparing meringue
* Finest grades
o 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.
Retailers also sell sugar cubes or lumps for convenient consumption of a standardised amount.
Brown sugars derive from the late stages of sugar refining, when sugar forms fine crystals with significant molasses-content, or by 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.
2006-09-18 01:22:41
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answer #1
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answered by Guru 3
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