Sugar
Authors: Colonna William J. , Samaraweera Upasiri , Clarke Margaret A. , Cleary Michael , Godshall Mary An , White J. S. ,   Updated by Staff
Published: February 2006

Sucrose is a nonreducing disaccharide produced by crystallization from syrups derived from processing sugarcane and sugarbeets. Sucrose’s most important properties are its water solubility and its sweetness. The latter is influenced by temperature, pH, etc, and is synergistic with other sweeteners. Sucrose is destroyed by strong oxidizing agents, and extremes of pH. Optical rotation, enzymatic analysis, and instrumental methods are used for sucrose quantitation. Sucrose is the leading food additive and contributes sweetness, mouthfeel, texture, body, humectancy, and appearance to foods. Sugar also enhances the taste of foods and minimizes undesirable flavors.

Sugar is one of the purest foods made from natural sources and has never been known to have harmful components.

This article outlines the history of sugarcane as a source of sucrose sweetener, and traces the development of major industrial unit processes for sugar production. Chemical and physical properties of sucrose and cane sugar are listed. Cultivation and harvest of sugarcane and product of either raw cane sugar or direct consumption (plantation white) cane sugar are described. Production of noncentrifugal cane sugar is described briefly. Production, consumption, and use statistics are given. Processes for refining raw sugar into refined white and brown products are delineated, and the products and their standards are described. Other products from cane sugar and sugarcane are described.

Sugar beets, grown in temperate climates predominately in the northern hemisphere, provide about one‐third of the world sugar supply and about half of the U.S. requirements. The crop is usually harvested at the end of the growing season and held in large storage piles until processing. Cultivation and processing of sugar beets are detailed.

Sugar analysis includes the determination of sucrose in raw sugar, along with other quality factors such as moisture, ash, and color, for trading purposes. It also includes the determination of reducing sugars in products of sugar manufacture and the determination of sugars in foods in general. Polarimetry, commonly called polarization in the industry, is the most widely used method for sugar analysis in commerce, and copper reduction methods are still commonly used for reducing sugars.

Esters, ethers, acids, polyurethanes, and other polymers are synthesized from sucrose. Sucrose esters are used as food emulsifiers, fat mimetics, detergents, bleach boosters, and antibacterials. Selective chlorination converts sucrose into sucralose, a noncaloric, high intensity sweetener. Alcohols, organic acids, antibiotics, dextrans, levans, and noncariogenic sweeteners are derived from sucrose by fermentation. Sucrose is used in medicines to mask unpleasant tastes, in tablet formulations, and to promote wound healing. Sucrose derivatives are used in treating ulcers and as antitumor agents. At current consumption rates, dietary sucrose promotes dental caries, but does not cause diabetes, hyperactivity, obesity, or heart disease.

Although commercially sucrose is the most important sugar, there are other special sugars with special applications, among which fructose is the most important. Fructose, a monosaccharide consisting of one‐half of the sucrose molecule but having a sweetness 1.3–1.8 times that of sucrose, constitutes 4–8 wt % of many fruits, where it primarily occurs with glucose (dextrose) and sucrose. Maltose (malt sugar) is a disaccharide comprising two molecules of glucose. Although occurring in some plants and fruits, it is more frequently recognized as a structural component of starch. Lactose (milk sugar) is the only commercially available sugar that is derived from animal rather than plant sources. It is a disaccharide consisting of one galactose and one glucose moiety and has only one‐fifth the sweetening power of sucrose.