The Chemistry of Sweeteners

Sugars are also known as carbohydrates. Table sugar is a sweet-tasting carbohydrate called sucrose. It is made up from two smaller sugar molecules (glucose and fructose) joined together and so it is also known as a disaccharide.

Notice the two rings joined together. Similar five- and six-ring structures are seen in many artificial sweeteners.

scrose molecule

Intense sweeteners

These have a diverse range of chemical structures and are very much sweeter than sugar and other bulk sweeteners such as xylitol. Intense sweeteners are generally used in products to reduce calories or for making tooth friendly sweets.

Blends of intense sweeteners are increasingly being used in foods. Combinations can be chosen to provide a taste profile far superior to that of the single sweetener. This results in the use of less sweetener.

Chemical Structure and Sweetness
Chemical Strcuture Sweetness Value Description
aspartame molecule 200 Aspartame is a dipeptide. It is a compound of two amino acids joined together (aspartic acid and phenylalanine). Only a very small amounts are needed for sweetening purposes
acesulfmae molecule 200 Acesulfame-K is a synthetic compound that acts as a synergist with other sweeteners. This means that a mixture of two sweeteners can be sweeter than an equal quantity of either sweetener alone
saccharin molecule 300 Saccharin is a synthetic compound. The taste of saccharin is not ideal when used alone or at high concentrations. It synergises well with acesulfame-K and is often used in this way
cyclamate molecule 30 Cyclamate are not as sweet as most of the other intense sweeteners and its taste is not ideal at higher concentrations but it is well suited for blending with other sweeteners
sucralose molecule 600 Sucralose is modified sucrose. This results in the body not being able to use it for energy and so whilst it retains the sweet taste of sugar it has no calories. It is also one of the strongest of the artificial sweeteners

A sweetness value of 600 means it is 600 times sweeter than sucrose!

Bulk sweeteners

This group is predominantly composed of the polyols , which are derivatives of normal sugars and exhibit carbohydrate-like structure and functionality. The polyols can often be used as direct replacements for sugar. Many of the polyols occur naturally to varying degrees, but most are produced commercially by hydrogenation of their corresponding sugar pre-cursors.

Polyols are suitable for diabetics by virtue of a reduced glycaemic index . They are also reported as being able to play a role in actively reducing the risk of tooth decay.

They may act as a laxative if consumed to excess and a warning to this effect is printed on package labels.

Chemical structure and sweetness of some bulk sweeteners
Chemical Structure Sweetness Value Name and E-Number
erythritol molecule 60%

Erythritol

E968

isomaly molecule 45%

Isomalt

E953

lactitol molecule 35%

Lactitol

E966

maltitol molecule 80%

Maltitol

E965

 

mannitol molecule 50%

Mannitol

E421

sorbitol molecule 60%

Sorbitol

E420

xylitol molecule 100%

Xylitol

E967

A sweetness value of 50% means it is only half as sweet as sucrose