14-05-2012, 03:27 PM
Sugar Plant
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Sugarcane is a perennial herb belonging to the grass family. Native to tropical and subtropical regions of the world, this tropical grass is 10-24-feet tall, bears long, pointed leaves, and has several stalks. The segmented stalks have a bud at each joint and as the plant matures, small flowers appear.
THE DIFFERENT TYPES
There are a bewildering number of sugars and syrups available in the shops while other types are available for the industrial user. Some of the basic differences are discussed below.
White sugar is essentially pure sucrose and there is no difference between that derived from cane and that from beet. Different manufacturers produce crystals of different sizes however and this leads to some apparent differences. Smaller crystals dissolve more readily and might therefore appear to be sweeter because none is left at the bottom of the cup and they seem sweeter on the tongue if eaten alone. Similarly smaller crystals have more surfaces per spoonful and appear whiter than larger crystals. [Having said that, some white sugars are less white than others: it depends on how much processing the manufacturer applies.]
There are several speciality white sugars:
caster sugar is just a very small crystal size white sugar
icing sugar is ground up white sugar, essentially sugar dust
sugar cubes are lumps of sugar crystals "glued" together with a sugar syrup
preserving sugar is a special large crystal
Brown sugars come in many different styles but are essentially one of two types: sticky browns and free-flowing browns. The sticky browns were originally the sort of mixture that comes out of a cane sugar crystallising pan. The extreme of this, still made in India today, is "juggeri" or "gur" which is essentially such a mixture boiled until dry.
In modern refining practice both of these types are made by mixing a refined or at least purified sugar with a suitable syrup. The colour of the sugar and the syrup determines the colour of the final product and the ratio of syrup to sugar plus any drying applied determines whether the product is sticky or free-flowing.
Syrups, of which there are again an enormous range, range from pure sucrose solutions as sold to industrial users to heavily treated syrups incorporating flavours and colours. Refiners or "Golden" syrup is a sugar solution which has been carefully treated to invert some of the sucrose. Inversion is a chemical process which breaks down the disaccharide sucrose to its constituent sugars: glucose and fructose. This helps ensure that crystallisation does not occur during storage. Treacle is a similar product made from molasses rather than a pure sugar
STEPS INVOLVED IN MAKING SUGAR PLANTING
Sugarcane cuttings are planted in fields by workers or mechanical planters. In order for the cane to grow, the seeds must be planted in well-drained soil. Typical cane soil is made of a mixture of silt, sand, clay particles and organic matter. Canes are spaced at least 4-feet apart and lined in rows and covered with soil. Fertilizers are applied from the time of planting up until the beginning of the ripening period. Cane fields are also routinely weeded to provide for optimum growth of the cane. Depending on the region where the crop is planted, cane seasons last from 8-22 months. In the United States, sugarcane is grown in Florida, Hawaii, Louisiana and Texas.
COLLECTING THE HARVEST
Mature canes are gathered by a combination of manual and mechanical methods. Canes are cut at ground level, its leaves are removed and the top is trimmed off by cutting off the last mature joint. Cane is then placed into large piles and picked up, tied, and transported to a sugar factory.
CLEANSING AND GRINDING
Stalks are thoroughly washed and cut when reaching the sugar mill. After the cleaning process, a machine led by a series of rotating knives, shreds the cane into pieces. This is known as "grinding." During grinding, hot water is sprayed on to the sugarcane to dissolve any remaining hard sugar. The smaller pieces of cane are then spread out on a conveyer belt.
JUICING
The shredded pieces of sugarcane travel on the conveyer belt through a series of heavy-duty rollers, which extract juice from the pulp. The pulp that remains or "bagasse" is dried and used as fuel. The raw juice moves on through the mill to be clarified.
CLARIFYING
Carbon dioxide and the milk of a lime are added to the liquid sugar mixture and it is heated to the boiling point, as the process of clarifying begins. As the carbon dioxide travels through the liquid it forms calcium carbonate, which attracts non-sugar debris (fats, gums, and wax) from the juice, and pulls them away from the sugar juice. The juice is then pushed through a series of filters to remove any remaining impurities.
EVAPORATION
The clear juice which results from the clarifying process is put under a vacuum, where the juice boils at a low temperature and begins to evaporate. It is heated until it forms into a thick, brown syrup.