Sucrose Vs. Fructose- What's The Difference?

Sucrose and fructose are commonly and naturally found substances. They are both carbohydrates, in the form of simple sugars. Both these sugars are processed to be used in commercially prepared food products. Since there are a number of similarities between the two, they are often compared, especially in matters relating to nutrition.

What we commonly call table sugar is nothing but the organic compound sucrose. It is a white, crystalline, odorless, sweet powder. Human beings have been consuming sucrose for a very long period of time. The molecule of sucrose is a disaccharide, which means it is made from two units of sugar ('di-' meaning two, and 'saccharide' meaning related to sugar).

The two molecules that make up sucrose are actually derived from glucose and fructose. The molecular formula of sucrose is C₁₂H₂₂O₁₁. It is one of the main ingredient used in confectioneries and desserts. It is also used a food preservative.

Fructose is also referred to as fruit sugar. It is a monosaccharide, and is found in a number of foods. It makes up the trio of important dietary monosaccharides, along with glucose and galactose. It is a white solid substance, which dissolves easily in water. Of all the sugars it is the most water-soluble. It is commonly found in honey, fruits, etc. It is one of the component molecules of sucrose. The chemical formula of fructose is C₆H₁₂O₆.

While fructose is found naturally in fruits, vegetables, and honey, sucrose is derived from maple syrup, beets, and sugar cane. There is no difference between the energy content in sucrose and fructose; both of them contain 4 calories of energy per gram. However, fructose is sweeter as compared to sucrose, therefore one has to use fructose in lesser quantities for the same kind of sweetness as sucrose. This is the reason why the former is often referred to as a low-calorie sweetener.

There is a difference in the digestion and absorption processes of the two. When you consume fructose, the intestine absorbs it directly, without it undergoing any reactions with any enzymes. However, when you consume sucrose or disaccharides, the digestive enzyme sucrase has to divide it into fructose and glucose. It is only after the division that the body is able to digest sucrose.

Sucrose contains one molecule of glucose. Therefore, when sucrose is consumed it triggers the release of insulin. It is when insulin is released that the glucose from the blood is taken up. On the other hand, there is not much of an insulin release after the consumption of fructose.

When fructose is consumed, it is said that it behaves like fat, with respect to the responses to it from various hormones. This can be attributed to the fact that there is no insulin secretion after consumption of fructose, or increase in the production of leptin. Consumption of high amounts of sucrose, on the other hand, leads to diabetes and obesity.