Comparison of Sucrose and Fructose

Sucrose and fructose are both simple sugars or carbohydrates. Monosaccharides are another name for fructose, which is a single sugar molecule. Sucrose is a disaccharide, meaning it is a sugar molecule containing glucose and fructose. 

Sugar is obtained naturally from natural foods and sugar-added processed meals. Although sucrose and fructose are both natural sugars that taste sweet on our lips, they are processed differently in our bodies.

Fructose 

Fructose is a monosaccharide, a form of sugar. Fructose, also known as ‘fruit sugar’, is one of the three most frequently occuring monosaccharides in nature. (Glucose and galactose are the other two.) Fructose is found in practically all fruits, as its name implies, but it is also found in commercial quantities in sugarcane, sugarbeets, and corn.

The disaccharide sucrose, sometimes known as ordinary sugar, is formed when fructose and glucose combine. It is known as D – fructopyranose in this form, whereas fructose occurs in water as an equilibrium combination of 70% fructopyranose, 22% fructofuranose, and 7% three other forms, including its acyclic structures. 

Six carbon atoms, twelve hydrogen atoms, and six oxygen atoms make up fructose. At carbon number 2, it has a ketone functional group. As a result, it is a ketohexose. 

Properties of fructose

Physical properties:

• The molar mass of fructose equals 180.16 g/mol.

• Fructose appears as white crystals

• Its melting point is 91–185 ºC (dec.)*

Chemical properties:

• Fructose has the chemical formula C6H12O6.

• One molecule of fructose has five hydroxyls and one ketone group.

• The ketone group in fructose is present in hemiacetal form rather than free form.

Sucrose

Sucrose is a glycosyl glycoside made up of glucose and fructose units connected by an acetal oxygen bridge from the glucose hemiacetal to the fructose hemiketal. 

It functions as an osmolyte, a sweetener, a human metabolite, an algal metabolite, a Saccharomyces Cerevisiae metabolite, an E. coli metabolite, and a mouse metabolite.

Sucrose is a disaccharide, which means it comprises two monosaccharides: glucose and fructose. Sucrose is a naturally occurring sugar refined and crystallised from white sugar. Its molecular formula is C12H22O11.

Properties of sucrose 

Physical properties:

• It is known as a crystalline substance that dissolves in water.

• This chemical decomposes at high temperatures (above 186oC), resulting in caramel.

• It dissolves in water at 20°C and has a solubility of 203.9g/100mL.

• The enthalpy of combustion for sucrose is 5647 kJ.mol-1, which is the standard value.

Chemical properties:

• Sucrose can be burned to produce carbon dioxide and water as a byproduct.

• When treated with chloric acid, this chemical produces hydrochloric acid, carbon dioxide, and water.

• The glycosidic connection that connects the two carbs in a C12H22O11 molecule is broken during hydrolysis, resulting in glucose and fructose.

• Sucrose can be dehydrated with the help of H2SO4 (which works as a catalyst) to produce a black carbon-rich solid.

Differences between sucrose and fructose

Sucrose and fructose are digested and absorbed in distinct ways:

• Fructose digestion and adsorption

Fructose, like glucose, is taken into the blood circulation immediately from the small intestine. It elevates blood sugar levels more slowly than glucose and does not affect insulin levels right away. On the other hand, fructose may have more long-term harmful effects than glucose because it does not immediately elevate blood sugar. Before our body can use fructose for energy, it must first be converted to glucose by our liver. 

• Sucrose digestion and adsorption

Because sucrose is a disaccharide, it must be broken down before our body can use it. Sucrose is partially broken down in our mouth by enzymes into glucose and fructose. However, the majority of sugar digestion takes place in the small intestine. Sucrose is broken into glucose and fructose by the enzyme sucrase, produced by the lining of our small intestine. They are absorbed into our bloodstream.

• Sweetness levels

Apart from its inexpensive cost, fructose’s great relative sweetness is the key reason for its commercial use in foods and beverages. It is the sweetest of all the carbohydrates found in nature. Fructose is typically thought to be 1.73 times sweeter than sucrose. The 5-ring form of fructose, on the other hand, is sweeter; the 6-ring form tastes similar to regular table sugar. The 6-ring form of fructose is formed when it is heated. The sweetness of fructose is detected earlier than that of sucrose or dextrose, and the taste peaks (higher than sucrose) and fades faster than that of sucrose.

• Glycemic index

Fructose has the lowest glycemic index (GI = 19) of all natural sugars since it is converted to glucose in the liver. Honey (typically roughly 50% fructose content) has a GI of 55, while standard table sugar (sucrose, which is half fructose) has a GI of 65. Products with high fructose content may be discouraged because excessive fructose consumption may cause various disorders, such as metabolic syndrome and insulin resistance.

Conclusion

Sucrose and fructose are both simple sugars or carbohydrates. Monosaccharides are another name for fructose, which is a single sugar molecule. Fructose, like glucose, is taken into the circulation immediately from the small intestine.

Because sucrose is a disaccharide, it must be broken down before our body can use it. Fructose is typically thought to be 1.73 times sweeter than sucrose. Fructose has the lowest glycemic index (GI = 19) of all natural sugars since it is converted to glucose in the liver.