The simplest definition of fructose and sucrose is that the first is a sugar found naturally in fruits while the second is table sugar.
Fructose is a simple sugar because it has a single sweetening molecule, making it a monosaccharide. Glucose and fructose combine to form the complex carbohydrate known as sucrose.
Characteristics of Fructose
Found naturally in fruits, honey, and vegetables, it is up to twice as sweet as sucrose and is the sweetest of the naturally occurring sugars. It is also a major component of high-fructose corn syrup. Because of this less fructose is used to achieve the same level of sweetness, meaning fewer calories will be consumed. However, because of this characteristic its flavor can be intensely cloying.
Fructose has a low glycemic index, meaning it does not cause a rapid rise or fall in blood glucose levels because t takes a long time for the body to break it down. When high sugar foods are consumed, blood sugar levels peak rapidly, then fall just as quickly, often resulting in a dip below normal blood sugar levels, and possibly enhancing appetite.
Although still unproven, some researchers believe that carbohydrates with a low glycemic index have health benefits such as preventing spikes in blood sugar levels of diabetics. The World Health Organization believes that fructose may even prevent type II diabetes, as well as obesity, and weight gain. Thanks to these various properties, glucose is often used as a sweetening agent in processed foods such as dairy product, preserves and commercially-prepared baked goods.
Characteristics of Sucrose
Sucrose is a complex carbohydrate that is also a disaccharide, meaning it is composed of two monosaccharides, which are fructose and glucose. The latter is the sugar that the human body converts into energy. Sucrose creates a quick energy boost because it is easily absorbed into the blood stream.
It is a white and crystalline in appearance, melting at 186 degrees C, thereby decomposing to form caramel. Brown sugar, the second most common form, is made by adding a small amount of molasses. Sources include sugar cane, sugar beets, and maple trees. Sugar is obtained from the juice of canes and beets, and the sap of maple trees.
Sucrose consisting of fine crystals is the best for cooking because they dissolve fastest and are easy to stir. Brown sugar is different in only that it appears to be more moist than white sugar and may be a white sugar substitute for cooking. Natural brown sugar is made from raw sugar and has a naturally brown color.