Sugar production
Sucrose, glucose, fructose as well as lactose are all available in retail stores. But how are they made? Glucose and fructose occur naturally in fruit and honey, but not in sufficient amounts to isolate the sugars within. Glucose is obtained from starch, fructose from sucrose, and, as the term milk sugar already indicates, the primary source of lactose is milk.
Sucrose, which in terms of quantity can be considered the most important form, is mainly obtained from sugar cane (cane sugar) and sugar beets (beet sugar), both of which directly store sucrose. Other plants such as potatoes and grains store sugar in the form of starch. Worldwide production of sucrose amounts to approximately 90 million tons a year. In Europe, the primary source of sucrose is the sugar beet.
Cane sugar
The process used to crystallise sugar from sugar cane juice was probably developed in India during the 4th century AD. Arab traders introduced the method to Europe during the Middle Ages and from there it was brought to the colonies of various European countries, where large sugar cane plantations were soon established. The pith of the high, thick stalks of the reed-like sugar cane contains up to 20 per cent sugar. The juice of the sugar cane plant is pressed and then further processed in a method similar to that used for beet sugar.
Beet sugar
Sugar beets have been industrially cultivated throughout Europe since the 19th century. They are made up of 16 to 22 per cent sugar. After harvesting, the beets are washed, chopped into small pieces, and rinsed with hot water. The cloudy “sugar water” still contains impurities, which prevent the crystallisation of the sugar. The juice is therefore further purified and then concentrated into a sugar syrup. Crystals eventually form, which are then separated from the syrup. Today, about 26 per cent of the world’s sugar is made from beets.
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