3 SUGAR SOURCES Sugar is a broad term

3. SUGAR & SOURCES

Sugar is a broad term applied to a large number of carbohydrates present in many plants and characterized by a more or less sweet taste. The primary sugar, glucose, is a product of photosynthesis and occurs in all green plants. In most plants, the sugars occur as a mixture that cannot readily be separated into the components. In the sap of some plants, the sugar mixtures are condensed into syrup. Juices of sugarcane (Saccharum officinarum) and sugar beet (Beta vulgaris) are rich in pure sucrose, although beet sugar is generally much less sweet than cane sugar. These two sugar crops are the main sources of commercial sucrose.

The Manufacturing Process 1. Planting and harvesting Sugarcane requires an average temperature of 75 F (23. 9 °C) and uniform rainfall of about 80 inches (203 centimeters) per year. Therefore it is grown in tropical or subtropical areas. Sugarcane takes about seven months to mature in a tropical area and about 1222 months in a subtropical area. At this time, fields of sugarcane are tested for sucrose, and the most mature fields are harvested first. The harvested cane stalks are taken to mills for processing into raw sugar.

2. Preparation and processing After the cane arrives at the mill yards, it is unloaded and excessive soil and rocks are removed. The cane is cleaned by flooding the carrier with warm water or by spreading the cane on agitating conveyors that pass through strong jets of water and combing drums (to remove larger amounts of rocks, trash, and leaves, etc. ). At this point, the cane is clean and ready to be milled.

3. Juice extraction pressing Two or three heavily grooved crusher rollers break the cane and extract a large part of the juice, or swing-hammer type shredders shred the cane without extracting the juice. Revolving knives cutting the stalks into chips are supplementary to the crushers. (In most countries, the shredder precedes the crusher. ) A combination of two, or even all three, methods may be used. The pressing process involves crushing the stalks between the heavy and grooved metal rollers to separate the fiber (bagasse) from the juice that contains the sugar. As the cane is crushed, hot water (or a combination of hot water and recovered impurejuice) is sprayed onto the crushed cane counter currently as it leaves each mill fordiluting. The extracted juice, called vesou, contains 95 percent or more of the sucrosepresent. The mass is then diffused, a process that involves finely cutting or shredding the stalks. Next, the sugar is separated from the cut stalks by dissolving it in hot water or hot Juices.

4. Purification of juice-clarification and evaporation The juice from the mills, a dark green color, is acid and turbid. The clarification (or defecation) process is designed to remove both soluble and insoluble impurities (such as sand, soil, and ground rock) that have not been removed by preliminary screening. The process employs lime and heat as the clarifying agents. The muds separate from the clear juice through sedimentation. The non-sugar impurities are removed by continuous filtration. The final clarified juice contains about 85 percent water and has the same composition as the raw extracted juice except for the removed impurities. To concentrate this clarified juice, about two-thirds of the water is removed through vacuum evaporation. Generally, four vacuum-boiling cells or bodies are arranged in series so that each succeeding body has a higher vacuum (and therefore boils at a lower temperature). The vapors from one body can thus boil the juice in the next one-the steam introduced into the first cell does what is called multiple-effect evaporation. The vapor from the last cell goes to a condenser. The syrup leaves the last body continuously with about 65 percent solids and 35 percent water.

5. Crystallization is the next step in the manufacture of sugar. Crystallization takes place in a singlestage vacuum pan. The syrup is evaporated until saturated with sugar. As soon as the saturation point has been exceeded, small grains of sugar are added to the pan, or "strike. ". Additional syrup is added to the strike and evaporated so that the original crystals that were formed are allowed to grow in size. The growth of the crystals continues until the pan is full. When sucrose concentration reaches the desired level, the dense mixture of syrup and sugar crystals, called massecuite, is discharged into large containers known as crystallizers. Crystallization continues in the crystallizers as the massecuite is slowly stirred and cooled. Massecuite from the mixers is allowed to flow into centrifugals, where thick syrup, or molasses, is separated from the raw sugar by centrifugal force.

6. Centrifuging The high-speed centrifugal action used to separate the massecuite into raw sugar crystals and molasses is done in revolving machines called centrifugals. A centrifugal machine has a cylindrical basket suspended on a spindle, with perforated sides lined with wire cloth, inside which are metal sheets containing 400 to 600 perforations per square inch. The basket revolves at speeds from 1, 000 to 1, 800 RPM. The raw sugar is retained in the centrifuge basket because the perforated lining retains the sugar crystals. The mother liquor, or molasses, passes through the lining (due to the centrifugal force exerted). The final molasses (blackstrap molasses) containing sucrose, reducing sugars, organic non sugars, ash, and water, is sent to large storage tanks. Once the sugar is centrifuged, it is "cut down" and sent to a granulator for drying. In some countries, sugarcane is processed in small factories without the use of centrifuges, and a dark brown product (non centrifugal sugar) is produced. Centrifugal sugar is produced in more than 60 countries while non centrifugal sugar in about twenty countries.

7. Drying and packaging Damp sugar crystals are dried by being tumbled through heated air in a granulator. The dry sugar crystals are then sorted by size through vibrating screens and placed into storage bins. Sugar is then sent to be packed in the familiar packaging we see in grocery stores, in bulk packaging, or in liquid form for industrial use.

Types of sugar • There are many different types of granulated sugar. Some of these are used only by the food industry and professional bakers and are not available in the supermarket. The types of granulated sugars differ in crystal size. Each crystal size provides unique functional characteristics that make the sugar appropriate for a specific food's special need.

• �Regular or white sugar, extra fine or fine sugar • �Fruit Sugar • �Bakers Special Sugar • �Superfine, ultrafine, or bar sugar • �Confectioners or powdered sugar • �Coarse sugar • �Sanding sugar

Brown Sugar • �Turbinado sugar • �Brown sugar (light and dark) • �Muscovado or Barbados sugar • �Free-flowing brown sugars • �Demerara sugar Liquid Sugar • � Invert sugar

Stage Coated Small Thread(gloss) Large Thread(Gloss) Small Pearl Large Pearl Description Translucent syrup about to come to boil. A coating will be formed on top of the surface of a spoon The consistency is tested by plunging fingers into cold water first, then quickly in sugar syrup. On parting the fingers carefully short threads of 23 mm will form and break easily Temperature 100° C(212 F) The thread obtained between fingers will be stronger and about 0. 5 cm wide. Round bubbles will form on surface of syrup. When taken between fingers, it forms a wide solid thread The thread of sugar between the fingers may reach a width 2 cm. when one blows on the skimmer is dipped into syrup, bubbles are formed on the other side 103°C(218°F) 102°C(216'F) 103 -105 °C(217 -221°F) 107 -109°C(224 -228 F) Soft(Small) Ball When the thickened syrup is dropped in water it will roll into a ball shape. If one blows on a skimmer dipped into syrup, bubbles break loose and blow away. 116 -118°C(241 -244 F) Hard(Large) Ball When the thickened syrup Is dropped in water it will roll into a hard ball. If one blows through skimmer snowy flakes are formed. 121 -124°C(250 -255°F) Soft(light or Small) Crack A drop of syrup in cold water hardens immediately and will crack and stick to teeth when chewed. The drops of syrup in cold water become hard and brittle, but notsticky. The sugar acquires a pale straw-yellow colour at the edges of the pan 129 -135°C(265 -275°F) Light Caramel The syrup at this stage will not contain any water, begins to change in to barley sugar, then into caramel. The colour will be yellow at first, becomes golden and then brown 151 -160°C(302 -325°F) Brown/Dark. Caramel(Black jack) Last stage of sugar cookery before carbonisation. The sugar losessweetness and turn dark brown in colour 161 -170 °C Hard Crack 149 -150°C(295 -300°F)

USES AND FUNCTIONS OF SUGAR Sugar Is not just a sweetener; it can be used in a number of different ways: • 1) As a preservative: at the right concentration sugar helps to stop microorganisms growing and so prevents food spoilage. For example, as in Jams and other preserves. This is why reduced sugar jams spoil much more quickly than traditional Jams. • 2) It helps to produce subtle changes in flavour: Sugar offsets the acidity and sour flavour In many foods such as mayonnaise, tomato products and tart fruits like gooseberries and grapefruit. • 3) As a bulking agent: sugar gives the characteristic texture to a variety of foods-including Jams, ice cream and cakes. • 4) To raise the boiling point or lower the freezing point. This is essential in some recipes, for example making ice cream. • 5) To speed up the process of fermentation (by yeast) in baking. This makes the dough rise, for example, bread and tea-cakes. • 6) It makes cakes light and open-textured when it is beaten with butter or eggs in a recipe. • 7) Low concentration of sugar speeds the effectiveness of baker's yeast by providing an Immediate, fast cooking source of nourishment for its growth-thus hastening the leavening process. • 8) The ability of sugar to crystallize, gives a delightful variety in cookery. • 9) Sugar gives puddings, bread, buns and bread rolls a good flavour and the characteristic golden brown colour, flavour (caramel) and a tender light and even texture.

Sugar Substitute: It is a food additive that duplicates the effects of the sugarin taste, usually with less food energy. Some sugar substitutes are natural and some are synthetic. Those that are not naturalare, in general, reffered to as artificial sweetener. • Natural Sugar Substitutes • �Barley Malt Syrup: This tastes a bit like molasses, and it's not as sweet as sugar or honey. It's mostly used to make beer, but it's also used to make breads or other baked goods. • �Coconut Syrup: Hawaiians like to pour this syrup on pancakes, but it's also used in several mixed drinks. • �Corn Syrup: This is thick, sweet syrup that's popular in America, but hard to find in other countries. Unlike other sweeteners, corn syrup doesn't crystallize and turn grainy when R's cold, so it's a good choice for frostings, fudge sauces, and candies. Baked N go goods made with corn syrup are molster and stay fresher longer than those made with sugar. • �Dark Corn Syrup: This corn syrup has a mild molasses flavour, and it's a common Ingredient in barbecue sauce, pecan pie. • �Orgeat: This sweet almond-flavoured syrup is used in many mixed drinks. • �Maple Syrup: It is made from the sap of sugar maples; maple syrup is a traditional topping for pancakes, waffles, and French toast. It's also used to make candles, frostings, candied yams, meat glazes, and baked beans. Lighter syrups usually have a more delicate flavour.

Artificial sweeteners • These materials often replace sugars in manufactured foods. These products often have the advantage for weight watchers that they have little or no calorific value. This is either because they are not metabolized by the body or they are used in small quantity as a consequence of great relative sweetness. • � Saccharin: The basic substance, benzoic sulfilimine, has effectively no foodenergy and is much sweeter than sucrose, but has an unpleasant bitter or metallic aftertaste, especially at high concentrations. It is used to sweeten products such as drinks, candies, biscuits, medicines, and toothpaste. • � Cyclamate: It is less expensive than most sweeteners, and is stable under heating. It is often used synergistically with other artificial sweeteners especially saccharin, the mixture of 10 parts cyclamate to 1 part saccharin is common and masks the off-tastes of both sweeteners • � Sorbitol: obtained by reduction of glucose. Sorbitol is found in apples, pears peaches, and prunes. • � Aspartame: Aspartame is an artificial sweetener. It is 180 times sweeter than sugar in typical concentrations, without the high energy value of sugar. This sweetener is marketed under a number of trademark names, including Equal, Nutra. Sweet, and Canderel, and is an ingredient of approximately 6, 000 consumer foods and beverages sold worldwide. It is commonly used in diet soft drinks, and is provided as a table condiment in some countries. It is also used in some brands of chewable vitamin supplements and common in many sugar-free chewing gums and has now been found in some chewing gums that are not sugar free. However, aspartame is not always suitable for baking because it often breaks down when heated and loses much of its sweetness. • � Xylitol: it can be extracted from corn fibre, birch, raspberries, plums, and corn. Xylitol is roughly as sweet as sucrose with only two-thirds the food energy.