At the end of the unit the student will be able to:
1 Explain the composition of sugar
2 Identify the different types of sugar
3 State the role of sugar in cooking
4 List the functions of sugar
The term’ sugar’ means ”SUCROSE”, it is 99. 9 percent pure sucrose. It IS extracted from either sugarcane or sugar beet and mainly used as a sweetening agent.
Sugar may be classified into two chemical groups
1. Mono-saccharides which means simple sugar like glucose& dextrose
2. Di-saccharides or compound sugar like maltose & lactose
Sugarcane was cultivated in India as early as 400 BC The principle source for extracting sugar is from sugarcane and sugar beet. In the beet the sugar is stored in the roots whereas in sugarcane it is stored in the stem. Sugar beet IS a crop of temperate climate Whereas sugarcane is a crop grown in tropical climate. Sugarcane contains 18 per cent sugar and sugar beet contains about 15 per cent.
Composition of sugar:
Sugar contains the following components:
Sucrose – 99 per cent
Minerals – 04 per cent
Moisture – 07 per cent
Manufacture of sugar:
Sugar is obtained from sugarcane by crushing them and collecting the juice. The juice thus gathered is heated and treated with lime to purify it and then it IS filtered. It Is evaporated until saturated solution is produced which is then crystallised. The uncrystallised syrup Which remains after the removal of sugar crystals is called molasses.
Refining of sugar beet :
The beets are sliced into strips and crushed. Milk of lime and carbon di oxide is added to filter it. It is then crystallised into sugar granules.
1. Centrifugal machines Spin off the molasses. This process is called affination.
2. Melting is the process of dissolving sugar in water.
4. Liquid thus obtained 13 cloudy and is filtered thereafter.
3. Milk of limra’ is added and carbon dioxide bubbled through the liquid to clarify it.
5. After filtration the liquid 13 brown in colour with impurities. This’ is further clarified through animal Charcoal. This is the char process.
6. This sugar liquor 1s concentrated and crystallised in a vacuum pan
7. When the crystals are of required size, they are separated from any liquor that IS left in a centrifugal machine.
8. The sugar crystals are then dried.
Properties of Sugar
Sugar contains the following properties:
1. Hydrolysis: The nature of sugar is such that it can be converted from compound sugar into simple sugar with the help of an enzyme. Ex-reaction of yeast in bread making process.
2. Rate of fermentation: It is a natural food for the yeast and speeds up the activity of the yeast. ‘
3. Sweetness and flavour: It gives sweetness and flavour to the product.
4. Absorption and retention: It can absorb moisture and retain it.
5. Browning reaction: It can undergo browning reaction when heated which gives flavour and colour to cakes.
6. Heat resistance: It can withstand heat and can be cooked to different stages.
(B) Types of sugar:
There are different types of sugar available in the market. Some of the commonly found varieties are as follows:
1. Castor sugar: Superfine granulated sugar used for making cakes and cookies.
2. Granulated sugar: Shaped into fine granules, it contains 99.7 percent sucrose and 0.06 per cent moisture. Most commonly used both for table and cooking purposes.
3. Powdered sugar: Sugar that is powered used in making dessert or sweets.
4. Cube sugar: This is granulated sugar moistened with syrup and moulded intg cubes and then dried. Used for sweetening hot drinks.
5. Brown sugar: Sugar crystals from coloured molasses syrup it usually contains 85 to 99.5 per cent sucrose.
6. Molasses: It is a by-product obtained in the process of sugar manufacture, it contains 85 to 92 per cent sucrose. It IS also rich m iron.
7. Glucose: Less sweet than sucrose also present in the body and fruits 1n natural forms
8. Icing sugar or confectioner’s sugar: Edible starch is added to the powdered sugar to prevent it from forming lumps. It contains three per cent starch Used for making icings.
9. Honey: This IS a form of natural sugar made by the bees from the nectar of flowers
10. Maple syrup: It IS a sweetner made from the sap of maple tree These trees store sugar in their roots which is later tapped and concentrated. It is eaten with pancakes, French toasts etc.
(C) Role of Sugar in Cooking
In the presence of water, sugar can be cooked to different stages.
|Temperature||Name Of Degree|
(d) Functions of sugar
1. Sweetening agent.
2. Gives crust colour to bread and cake.
3. Retains moisture and prevent the product from drying out.
5. Speeds up the activity of yeast.
6. Delays the coagulation of proteins in eggs.
4. Preservative, for example, canned fruits & murrabba.
7. Creaming agent.
8. Helps to entrap air when creamed with fat.
|Sweetener||Drinks, Cakes, Pastries|
|Crust colour||Browing of cakes, breads|
|Main Ingredients||Sugar candies, toffees.|
|Structural ingredient||It strengthens egg white, for example in meringue.|
|Activator||It speeds up yeast fermentation, for e.g. in breads.|
Storage of sugar:
1. Store Sugar always in a dry cool place
2. It should be put into airtight containers.
3. It should be stored away from direct sunlight.
Sugar IS an essential ingredient which adds sweetness to the dish and also helps in the preservation of fruits It improves the eating quality of the product by preventing it from drying out.