Saccharin

The oldest sweetener of them all was discovered around 1879. Saccharin itself is about 550 times sweeter than sugar, while sodium-type saccharin has 450 times the sweetening strength of sugar. An important advantage of saccharin is its stability in heat and cold. Saccharin also keeps well in solutions of water such as lemonade. The strong flavour that used to be associated with saccharin has now been virtually eliminated as a result of improvements. Saccharin and cyclamate together makes an optimum combination that increases the sweetening power while providing a rounded, sugar-like flavour.

Cyclamate

Cyclamates were discovered around 1935. Cyclamate has 35 times the sweetening power of sugar. Cyclamate is known for its excellent flavour, and has proven itself particularly in combination with saccharin. Cyclamate plus saccharin remains stable in cooking and baking. Saccharin and cyclamates are excreted by the human body via the kidneys unchanged.

Aspartame

Aspartame is a more recent sweetening agent, having been discovered only in 1965. It is a sweetening agent based on quasi-natural protein components and is metabolised with them. It consists of two nutrition-biological active amino acids that occur in over half of all of foodstuffs, namely phenylalanine and asparagine. With around 4 kca/g, aspartame is thus not wholly calorie-free. However, it has considerable sweetening strength, being 200 times sweeter than sugar.
In the USA, aspartame is known under the registered brand name NutraSweet. A marked benefit of aspartame compared with other sweetening agents is its pleasant, purely sweet sugar-like taste. Aspartame is less suitable for heating to high temperatures, so is not recommended for cooking and baking or for products sterilised by heat.
Sweetening agents have synergetic characteristics, which means that the sweetening strength of combinations of sweetening agents is greater than the sum of individual sweetening agents.

Acesulfame K

Acesulfame K (E950), or Acesulfame Potassium, is a calorie-free sweetener approved for use since 1983. It is an organic synthetic salt. It is 200 times sweeter than sugar, has synergistic sweetening effect with other sweeteners, has a long shelf-life and is heat stable
It is often used as part of the sweetener composition of beverages.

Sucralose

Sucralose (E955) is a zero-calorie sugar substitute artificial sweetener approved for use in the European Union since 2004. It is the only low calorie sweetener that is made from sugar. Sucralose is produced by changing three alcohol groups on the sugar molecule with three chlorine atoms. This results in a stable sweetener that tastes like sugar without the calories. It is about 600 times sweeter than sugar.  It is heat stable and can be used for baking and for products that require a longer shelf life.

Stevia

Stevia rebaudiana Bertoni is a small shrub native to South America. It is a member of the Asteraceae family and has proven adaptable to cultivation in many parts of the world. For centuries its leaves have been used by the Guarani people of Paraguay to sweeten beverages, until it was discovered by the Italian-Swiss botanist Dr. Moisès Santiago de Bertoni (1857-1929). The sweet components found in the Stevia leaf are up to 200 times sweeter than sugar and have no caloric content.
Rebaudioside A (Reb A) is the sweetest and purest extract of the Stevia leaf. This is used for the sweetener.
Stevia is not yet allowed in the European Union. The authorisation procedure is in progress.