Not All Sugars Are Created Equal
Glucose is a naturally-forming sugar produced by the body after consuming certain types of foods. Sucrose is also a naturally-forming sugar, but it is found in plants like sugar beets and sugar cane, which are processed for human consumption. Although it is technically correct to call both of these substances "sugar," the differences in their methods of production and chemical composition affect how they taste.
How the Body Produces Glucose
Glucose, also known as "blood sugar," is a simple carbohydrate that flows through the bloodstream. Its purpose is similar to a battery in a radio or clock. Without it, people would not have enough energy to function properly. The body produces glucose after the consumption of food, particularly complex carbohydrates like bread, rice, potatoes, and pasta. The digestive process breaks down the molecules in these foods and the liver transforms them into a form of energy that the body can use: glucose. Although the end result of this process is sugar, the original foods consumed may not taste or smell sweet at all.
How Manufacturers Produce Sucrose
Sucrose, also known as "table sugar," is a simple carbohydrate that flows through the cells of plants. The sugar available for purchase in supermarkets is sucrose that has been commercially produced by refining sugar cane or sugar beets. The refining processes are slightly different for each plant, but the basic steps are: extracting the juice from the plant, filtering out dirt and other impurities from the juice, and boiling the water out of the filtered liquid. Once all of the water has evaporated, what remains is pure sucrose, which has a naturally crystalline form. Sucrose tastes sweet, as do most foods that are prepared with sucrose.
Why Two Forms of Sugar Taste Different
The taste buds on the tongue are comprised of chemical sensors that send signals through the nervous system and tell the brain how to interpret whether a food is sweet, salty, sour, or bitter. Food is comprised of molecules, and the geometric shape of these molecules determines how the taste buds interpret them.
The geometric shapes of glucose and sucrose molecules are different. Glucose is comprised of six carbon atoms, connected by six elements of water, and it is created after the process of digestion, which is why the food originally consumed may not taste sweet. Sucrose is a sugar before digestion. It is made up of one molecule of glucose and one molecule of fructose, another naturally-forming sugar commonly found in fruit. The result of this combination of two sugars is a geometric shape that taste buds interpret as sweeter than glucose.