Text C. Sugar crops

Sugar crops are crops produced as major sources of sugar, syrup, and other substances.

Sugar beet and sugar cane. These are crops which serve as a source of sucrose, the sugar of commerce. Sugar is a broad term applied to a large number of carbohydrates that have a more or less sweet taste. The primary sugar, glucose, is a product of photosynthesis and occurs in all green plants. Through chemical union, diverse sugars and starches are elaborated and become the major reserve food in storage organs, fruits and sap of plants. In most plants the sugars occur as a mixture that cannot be readily separated into the components. In the sap of some plants the sugar mixtures are condensed into syrup. The juices of sugar cane and sugar beet are unusually rich in pure sucrose. These two sugar crops serve as the sources of commercial sucrose.

Other sugar crops are sweet sorghum, sugar maple, sugar palm, honey and corn sugar.

Sugar maple. Colonists learned from the American Indians the art of making sugar and syrup from the sap of certain maple trees of the Great LaKes and St. Lawrence River region. The techniques, once used only for maple sugaring at home, have been for many years the basis of commercial production of sugar and syrup.

The trees are tapped for sap in early spring before the buds open. A large tree may be tapped each spring for many years. Trees vary greatly in yield of sap and sugar. The sugar in maple is almost 100% sucrose.

Sugar palm. Palm sugar is obtained from the sap of several species of palm in tropical regions of the world. In eastern Asia and Malaysia, where the production of palm sugar is an important village industry, the sugar palm is the major source of sap. The sap is collected from the stalk of the male flower rather than by tapping the trunk of the palm, as practiced with the maple tree. The sap contains 10 - 16% sucrose. In processing, the sap is condensed by heating until it becomes a thick syrup in which the sucrose crystallizes. The viscous mass is poured into molds to form small cakes of sweet substance.

Corn sugar and syrup. These are produced by the inversion of starch to its component sugar. These sweeteners have wide use in bakery, confectionery, and beverage industries.

Some varieties of corn have a sweet juice in the stalks. Cornstalk juice is reported to have been a source of a sweet substance used by Indians of Central America.